WO2020216913A1

WO2020216913A1 - Container lid allowing spectroscopy

Info

Publication number: WO2020216913A1
Application number: PCT/EP2020/061479
Authority: WO
Inventors: Jochen Brill; Michel Valentin KETTNER; Christoph Lungenschmied; Robert SEND; Wilfried HERMES
Original assignee: Trinamix Gmbh
Priority date: 2019-04-25
Filing date: 2020-04-24
Publication date: 2020-10-29

Abstract

A container lid (110) for closure of a chemical container (114), specifically for liquid chemicals, is disclosed. The container lid (110) comprises: - a lid body (130), wherein an optical window element (132) is disposed within the lid body (130); - a mechanical connection element (134) for mechanically connecting the container lid (110) to the chemical container (114);10 - at least one reflective element (140) positioned such that, when the container lid (110) is mechanically connected to the chemical container (114), the reflective element (140) at least partially is positioned in an interior space (124) of the chemical container (114); and - at least one sample space (144) fluidically connected to the interior space (124) of the chemical container (114) when the container lid (110) is mechanically connected to the chemical container (114), wherein the sample space (144) is located in between the reflective element (140) and the optical window element (132).

Description

Container Lid allowing Spectroscopy

Technical Field

The invention relates to a container lid for closure of a chemical container, a chemical container system, a spectrometer system, various uses of the use of the container lid, the container sys tem and the spectrometer system, and to a method for spectroscopic analysis of at least one sample. Such devices, systems and methods can, in general, be employed for investigation or monitoring purposes, in particular, in the infrared (IR) spectral region, especially in the near- infrared (NIR) and the mid-infrared (MidIR) spectral regions. The invention, as an example, may be used for product verification purposes and for detecting product piracy. Other fields of appli cation are possible, such as custom controls, medications and their verifications including anti counterfeiting, tax control in fuels or the like.

Background art

In many fields of technology, the identification and verification of products, specifically liquid products in containers, is of significant importance. Thus, as an example, in crop protection, herbicides, fungicides, insecticides or other active chemical substances are often sold as liquid chemicals in containers.

The containers may be combined with a packaging or lid having a dosing means, in order to facilitate the dosing of the active ingredient for the customer, since both overdosage and under dosage may be critical for the performance and direct contact to the substances should be avoided. One example for such a lid is given in WO 95/27187 A1 which discloses a tubular two- chamber liquid metering device for leaktight insertion into a container opening. The metering device comprises a cylindrical wall with a closed base and a cover which is provided with a pas sage for a pouring duct. The wall has at least one opening in the region of the cover and at least one further opening is located on a peripheral line between the opening and the base. Disposed in the outer cylindrical chamber defined by the wall, the base and the cover form a tubular body which at one end is connected in a leaktight manner to the pouring duct and at its other end maintains a distance from the base. The tubular body has at least one opening on a peripheral line in the region of the connection to the pouring duct. A freely movable body with a circular cross-section is provided in the main metering chamber defined by the inner cylinder between the opening and the base.

The chemical substances contained in the containers, however, are often affected by product piracy or other illegal actions. Thus, as an example, products may be illegally sold in a diluted form or containing cheaper and/or inappropriate ingredients. Further, active ingredients may be made without a license. The detection of manipulated products or even product piracy in the field imposes significant technical challenges. Thus, as an example, for many customers such as farmers the detection of falsified or manipulated products is technically impossible. Specifi- cally, the detection of counterfeiting, dilution or manipulated composition of products remains an issue.

For laboratory purposes, various spectroscopic solutions for product authentication or product verification exist. Various spectrometer devices and systems for investigations in the infrared (IR) spectral region, especially in the near-infrared (NIR) spectral region, are known. The spec trometer devices and systems generally comprise one or more wavelength-selective elements for separating incident light into a spectrum of constituent wavelengths and one or more detect ed devices for detecting the constituent wavelengths, such as one or more prisms, gratings, filters or the like. Especially, spectrometer devices which comprise a combination of a linearly variable filter (LVF) and a detector array have already been proposed. Flerein, the LVF is desig nated for separating light captured from an object, also referred to as a sample, into a spectrum of constituent wavelength signals while the detector array includes a plurality of pixels, wherein each of the plurality of pixels is disposed to receive at least a portion of a plurality of the constit uent wavelength signals that provides a power reading for each constituent wavelength. Typi cally, in order to accomplish that the incident light may impinge the LVF in a manner normal to a receiving surface of the LVF, a baffle is used for this purpose, which, however, generally results in a low light throughput and a poor signal-to-noise ratio.

For applications in the field, portable spectroscopic devices have been developed. Thus, as one of the various examples, US 2014/131578 A1 discloses a portable spectrometer device which includes an illumination source for directing at a sample as well as a tapered light pipe (TLP) for capturing the light which interacts with the sample at a first focal ratio and for delivering the light at a second focal ratio lower than the first focal ratio to the LVF.

The application of mobile spectroscopy in the field, however, imposes some additional technical challenges on the user. Thus, as an example, samples have to be taken from a container, have to be transferred into a suitable sample container and, further, have to be analyzed under well- defined conditions. The implementation of these handling steps, however, often turns out to be quite tedious for the customer or user. Specifically, additional training and equipment, in addi tion to the hand-held spectrometer may be required, and the user may even take the risk of get ting in contact with the chemical during analysis.

Problem to be solved

It is therefore desirable to provide for devices and methods addressing the above-mentioned technical challenges of known solutions. Specifically, devices and methods are desirable allow ing for a convenient analysis of the product in the field, specifically with a mobile spectrometer. Specifically, a convenient way for analysis, authentication or verification of a product contained in a chemical container is desirable, which avoids contamination of the user with the product and which, still, provides reliable analytical results.

Summary This problem is addressed by a container lid for closure of a chemical container, a chemical container system, a spectrometer system, various uses of the use of the container lid, the con tainer system and the spectrometer system, and a method for spectroscopic analysis of at least one sample. Advantageous embodiments which might be realized in an isolated fashion or in any arbitrary combinations are listed in the dependent claims.

As used in the following, the terms“have”,“comprise” or“include” or any arbitrary grammatical variations thereof are used in a non-exclusive way. Thus, these terms may both refer to a situa tion in which, besides the feature introduced by these terms, no further features are present in the entity described in this context and to a situation in which one or more further features are present. As an example, the expressions“A has B”,“A comprises B” and“A includes B” may both refer to a situation in which, besides B, no other element is present in A (i.e. a situation in which A solely and exclusively consists of B) and to a situation in which, besides B, one or more further elements are present in entity A, such as element C, elements C and D or even further elements.

Further, it shall be noted that the terms“at least one”,“one or more” or similar expressions indi cating that a feature or element may be present once or more than once typically will be used only once when introducing the respective feature or element. In the following, in most cases, when referring to the respective feature or element, the expressions“at least one” or“one or more” will not be repeated, non-withstanding the fact that the respective feature or element may be present once or more than once.

Further, as used in the following, the terms "preferably", "more preferably", "particularly", "more particularly", "specifically", "more specifically" or similar terms are used in conjunction with op tional features, without restricting alternative possibilities. Thus, features introduced by these terms are optional features and are not intended to restrict the scope of the claims in any way. The invention may, as the skilled person will recognize, be performed by using alternative fea tures. Similarly, features introduced by "in an embodiment of the invention" or similar expres sions are intended to be optional features, without any restriction regarding alternative embodi ments of the invention, without any restrictions regarding the scope of the invention and without any restriction regarding the possibility of combining the features introduced in such way with other optional or non-optional features of the invention.

In a first aspect of the present invention, a container lid for closure of a chemical container, spe cifically a chemical container for liquid chemicals, is disclosed. The container lid comprises:

a lid body, wherein an optical window element is disposed within the lid body;

a mechanical connection element for mechanically connecting the container lid to the chemical container;

at least one reflective element positioned such that, when the container lid is me chanically connected to the chemical container, the reflective element at least par tially is positioned in an interior space of the chemical container; and at least one sample space fluidically connected to the interior space of the chemical container when the container lid is mechanically connected to the chemical contain er, wherein the sample space is located in between the reflective element and the optical window element.

The term“container lid” as used herein is a broad term and is to be given its ordinary and cus tomary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a device or a combi nation of devices configured for closing and opening or a mouth of a container, specifically for reversibly closing the container. The container lid, as an example, may comprise one or more of a cap, a cover, a cover plate, a vial cap, a stopper, a screw cap, a crimped cap, a crown seal or similar devices. The container lid may be configured for mechanical connection to the container, such as by one or more of a form-fit connection, a force-fit connection or by adhesive bonding. As an example, the container lid may comprise one or more connection elements for connecting the container lid to the container. The term“closure” as used herein specifically may refer to a sealing of at least one opening. For the purpose of closure, the container lid may cover the at least one opening of the chemical container and/or a fully or partially be inserted into the open ing of the chemical container and/or may fully or partially surround a rim of a mouth of the con tainer having the opening.

The term“container” as used herein is a broad term and is to be given its ordinary and custom ary meaning to a person of ordinary skill in the art and is not to be limited to a special or cus tomized meaning. The term specifically may refer, without limitation, to a device or a combina tion of devices configured for holding one or more substances, specifically chemicals, more specifically amorphous substances such as liquids, granular substances or powders. The con tainer specifically may comprise a container wall surrounding one or more interior spaces, the container wall specifically having one or more openings for insertion of the substance, the open ing being closable by the container lid. The container wall specifically may be made of at least one material selected from the group consisting of a plastic material, a metal and glass. Other materials, however, are feasible. The container, as an example, specifically may comprise at least one of a bottle, a barrel or a canister. The container, as an example, specifically may be configured for holding large amounts of liquid chemicals, such as amounts of 100 ml. to 500 L of liquid chemicals, specifically amounts of 500 ml. to 200 L of liquid chemicals.

The term“chemical” as used herein, as well as the term“substance”, may generally refer to an arbitrary material to be transported by the container, such as a solid material, a gaseous mate rial or a liquid. Specifically, the chemical may be in an amorphous form. Thus, as an example, the chemical may comprise a liquid chemical, such as at least one liquid chemical selected from the group consisting of: a pesticide; a fungicide, a herbicide, a rodenticide, a pharmaceutical or drug; a fuel; a fertilizer; a solvent. Other chemicals are possible.

The term“lid body” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to an element or a combination of elements suited for providing mechanical stability and/or mechanical protection to the container lid. Thus, as an example, the lid body may be made of at least one basic material, such as at least one rigid basic material, and/or may provide a frame for one or more remaining parts of the lid, such as the window element. The lid body, as an example, may be made of one or more of a plastic material, a metal or a glass. Composite materials are feasible, too.

The lid body, as outlined above, comprises at least one optical window element disposed within the body. As an example, the optical window element may be disposed concentrically on a rota tional axis of the lid body. Other embodiments, however, are feasible too. The term“optical win dow element” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to an element which is fully or par tially transparent for light in one or more of the visible spectral range of 380 nm to 780 nm, the infrared spectral range of 780 nm to 1 mm, specifically the near-infrared spectral range of 0.78 pm to 3.0 pm, and the ultraviolet spectral range of 100 nm to 380 nm. More specifically, as will be outlined in further detail below, the element may be fully or partially transparent for light in the spectral range of 1 100 nm to 2500 nm. The term“transparent”, as used therein, specifically may refer to a transparency of at least 20%, more specifically of at least 50%, more specifically of at least 90%, as will be outlined in further detail below.

The optical window element, as an example, may be contained in a frame of the lid body, such as by disposing a disk-shaped optical window element and/or a lens-shaped optical window element within the frame. Thus, as an example, the lid body may contain an opening forming a frame, wherein the optical window element fully or partially closes the opening in the lid body. Alternatively, however, the optical window element may form part of the lid body, such as by rendering at least one part of the lid body transparent in one or more of the above-mentioned spectral ranges, e.g. by using one or more materials for the lid body which are transparent in the above-mentioned sense.

As further outlined above, the container lid contains at least one mechanical connection element for mechanically connecting the container lids to the chemical container. The term“mechanical connection element” as used herein is a broad term and is to be given its ordinary and custom ary meaning to a person of ordinary skill in the art and is not to be limited to a special or cus tomized meaning. The term specifically may refer, without limitation, to an arbitrary element or a combination of elements configured for mechanically engaging at least one further element or device, thereby connecting the part containing the mechanical connection element with the at least one further element or device. The mechanical connection element may, as will be out lined in further detail below, contain one or more of a connection element configured for forming a form-fit connection and/or a force-fit connection with the container. As an example, the me chanical connection element may comprise at least one thread, specifically at least one internal screw thread, as will be outlined in further detail below. The mechanical connection element specifically may contain at least one mechanical connection element which is suited for engag- ing with at least one complementary mechanical connection element, such as with at least one counterpart mechanical connection element. Thus, the chemical container may comprise at least one counterpart mechanical connection element configured for engaging with the mechan ical connection element of the container lid. The mechanical connection element specifically may be configured for securing the container lid to the container, thereby e.g. providing for an air-tight and/or liquid-tight closure of the opening of the chemical container by the container lid.

As further outlined above, the container lid comprises at least one reflective element. The term “reflective element” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to an element or a combination of elements having at least one surface having a reflectance of at least 20%, more specifically of at least 50% and most specifically of at least 90%, in one or more of the visible spectral range of 380 nm to 780 nm, the infrared spectral range of 780 nm to 1 mm, specifically the near-infrared spectral range of 0.78 pm to 3.0 pm, and the ultraviolet spectral range of 100 nm to 380 nm. More specifically, as will be outlined in further detail below, the reflective element may be fully or partially reflective for light in the spectral range of 1100 nm to 2500 nm. The term“reflectance” as used herein is a broad term and is to be given its ordinary and customary meaning to a per son of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a ratio R of a reflected intensity of light IR and the incident intensity of light lo: R=IR/I_O. The reflected light, therein, may be reflected in a directed fashion or in a diffuse fashion. The reflective element specifically may contain at least one flat or slightly curved reflective surface, such as at least one reflective surface having a radius of cur vature of at least 40 mm, more preferably of at least 50 mm or at least 100 mm.

The at least one reflective element is contained and positioned in the container lid, e.g. relative to the mechanical connection element, such that, when the container lid is mechanically con nected to the chemical container, the reflective element at least partially is positioned in an inte rior space of the chemical container. Therein, the reflective element specifically may be posi tioned such that the at least one reflective surface of the reflective element faces the optical window element, thereby allowing for a straight optical path between the reflective element and the optical window element. Alternatively, however, in between the reflective surface and the optical window element, one or more additional reflective elements may be positioned, thereby providing for a non-straight optical path in between the reflective surface and the optical window element, such as an optical path with one or more reflections.

As outlined above, the interior space of the container may fully or partially be surrounded by the at least one container wall. The container wall may contain the at least one opening to be closed by the container lid. The reflective element, thus, is positioned relative to the optical win dow element such that the reflective element is located on the inside of the container. Thus, the mechanical connection element may define an orientation of mechanical connection of the con tainer lid to the container, thereby defining an inner side of the optical window element and an outer side of the optical window element, wherein the reflective element is positioned on the inner side. For positioning the reflective element relative to the optical window element, the con tainer lid may contain at least one spacer element, as will be outlined in further detail below.

The spacer element may be separate from the reflective element and/or may fully or partially be comprised by the reflective element or vice versa. As an example, the spacer element may con tain at least one spacer rod or spacer bar protruding into the interior space of the container, wherein the reflective element is contained at an end of the spacer element. Additionally or al ternatively, the spacer element may also contain at least one mechanical holding structure or mechanical frame protruding into the interior space of the container, wherein the reflective ele ment is held by the mechanical holding structure or mechanical frame.

As further outlined above, the container lid comprises at least one sample space fluidically con nected to the interior space of the chemical container when the container lid is mechanically connected to the chemical container, wherein the sample space is located in between the re flective element and the optical window element. The term“sample space” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to an arbitrary space, compartment or chamber which is fully or partially fillable with a sample of the chemical contained within the container, specifically a fluid chemical sample. The sample space may fully or partially be surrounded by one or more walls. Alterna tively, however, the sample space may be an open sample space. The sample space, on one side, may be delimited by the reflective element. On an opposite side, the sample space may be open or may be delimited by a further element, such as the optical window element. Thus, the sample may fill the space in between the optical window element and the reflective element. Alternatively, however, the sample may only fill part of this space in between the optical window element and the reflective element. The sample space is located in between the reflective ele ment and the optical window element. Therein, the term“in between” specifically may refer to the fact that the sample space, specifically, may be located in an optical path in between the optical window element and the reflective element, such that the light in one or more of the above-mentioned spectral ranges, propagating from the optical window element to the reflective element or vice versa, crosses the sample space.

The sample space is fluidically connected to the interior space of the container. Thus, the fluidi- cal connection generally may allow for an exchange of liquids in between the interior space of the container and the sample space. For this purpose, one or more of the optional walls of the sample space may contain one or more openings, allowing for a sample of a liquid chemical contained within the interior space to enter the sample space. Alternatively, however, as out lined above, the at least one reflective element may be held by at least one open mechanical holding structure or open mechanical frame allowing for a liquid exchange between the sample space and the interior space of the chemical container.

As outlined above, the mechanical connection element generally may be suited for forming at least one of a form-fit connection and a force-fit connection with the chemical container, specifi cally with at least one counterpart mechanical connection element on the side of the chemical container. Specifically, the mechanical connection element may be or may comprise at least one element selected from the group consisting of: a thread, specifically an internal screw thread; a flange; a clip.

The optical window element specifically may be made of at least one plastic material. The plas tic material may be separate from a material of the at least one lid body and/or may be identical to the material of the at least one lid body. The plastic material of the optical window element specifically may comprise at least one plastic material selected from the group consisting of: a polyolefin, specifically polypropylene or polyethylene; a polyester, specifically polyethylene ter- ephthalate; a fluorinated polymer, specifically polytetrafluoroethylene; a chlorinated polymer, specifically polyvinylchloride; a polystyrene; a polyamide, specifically PA6; a polyacrylate, spe cifically poly(methyl methacrylate).

The optical window element specifically may have a thickness of 3 pm to 3 mm, specifically a thickness of 5 pm to 1 mm, more specifically a thickness of 10 pm to 500 pm. Thus, as an ex ample, the optical window element may be a rigid optical window element and/or may fully or partially be designed as a foil.

The optical window element may fully or partially be made of at least one material having a transmittance of at least 10 % over the spectral range of 1400 nm to 2000 nm or even over the spectral range of 1300 nm to 2500 nm. Therein, the term“transmittance” is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limita tion, to the ratio of the transmitted intensity of light I_T and the incident intensity of light lo: T=IT/I_O, usually indicated in %, i.e. T [%] = l/lo 100%. The transmittance of the optical entrance window element specifically may be at least 30% over the spectral range of 1400 nm to 2000 nm. More specifically, the transmittance T of the optical entrance window element may be at least 10% for every wavelength in the spectral range of 1400 nm to 2000 nm.

As outlined above, the container lid may further comprise at least one spacer element config ured for separating the reflective element from the lid body and for holding the reflective ele ment. The term“spacer element” is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a mechanical device, a mechani cal element or a combination of mechanical elements configured for holding and/or positioning at least one further element in a well-defined position and/or orientation and/or separation from at least one reference element. Specifically, the spacer element, as outlined above, may com prise at least one spacer rod or spacer bar protruding into the interior space of the container, wherein the reflective element is contained at an end of the spacer element. Additionally or al ternatively, the spacer element may also contain at least one mechanical holding structure or mechanical frame protruding into the interior space of the container, wherein the reflective ele ment is held by the mechanical holding structure or mechanical frame. Specifically, the spacer element may protrude from the lid body into the interior space of the chemical container when the container lid is mechanically connected to the chemical container.

As outlined above, the spacer element specifically may position the reflective element relative to the optical window element at a specific distance. Therein, specifically for spectroscopic pur poses, the distance between the optical window element and the reflective element may be 500 pm to 50 mm, specifically 100 pm to 20 mm, more specifically 200 pm to 8 mm. Therein, the term“distance” may refer to a geometric distance or geometric separation and/or may refer to an optical path length between the optical window element and the reflective element, specifi cally an optical path length in absence of the liquid chemical and/or sample in the sample space.

The container lid may further comprise at least one spectrometer connection element config ured for connecting the lid body to at least one spectrometer device located outside the interior space of the container. As used therein, the term“spectrometer connection element” may gen erally refer to an arbitrary element or combination of elements configured for mechanically con necting the spectrometer to the container lid or vice versa.

The term“spectrometer device” is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a device capable of optically ana lyzing at least one sample, thereby generating at least one item of information on at least one spectral property of the sample. Specifically, the term may refer to a device which is capable of recording the signal intensity with respect to the corresponding wavelength of a spectrum or a partition thereof, such as a wavelength interval, wherein the signal intensity may, preferably, be provided as an electrical signal which may be used for further evaluation. The spectrometer device specifically may be or may comprise at least one mobile spectrometer device, i.e. a spectrometer device capable of being moved by a human user, specifically capable of being carried by a human user. The spectrometer device specifically may be or may comprise at least one hand-held and/or mobile spectrometer device, specifically a spectrometer device having a weight of no more than 5 kg, specifically a weight of 3 kg or less.

The spectrometer connection element and the mechanical connection element specifically may be located on opposite sides of the lid body. Thus, as outlined above, the mechanical connec tion element for connecting the container lid to the container may be located on a first side, and the spectrometer connection element may be located on a second, opposing side.

The spectrometer connection element may fully or partially surround the optical window ele ment. Thus, as an example, the spectrometer device may comprise a housing having an en trance window, wherein the spectrometer connection element of the container lid interacts with a corresponding connection element fully or partially surrounding the entrance window of the spectrometer device. When the spectrometer device is connected to the container lid, thus, the entrance window of the spectrometer device and the optical window element of the container lid may be positioned such that the light from the interior space of the container may pass through the optical window element and through the entrance window of the spectrometer device, into an interior space of the spectrometer device inside the housing.

The spectrometer connection element specifically may comprise at least one element selected from the group consisting of: a magnet, specifically a ring-shaped magnet surrounding the opti cal window element; a thread, specifically a male thread; an adapter element for connecting the spectrometer device to the lid body, specifically a tubular adapter element; a clip. Other ele ments or combinations of two or more of these elements are feasible.

The lid body specifically may have a cylindrical shape, specifically a rotationally symmetrical shape. The optical window element and the reflective element are located on a cylinder axis of the lid body.

As outlined above, the reflective element specifically may at least partially be made of at least one of: a plastic material; a metal. Other materials, however, are feasible too, such as glassy materials. The reflective element at least partially may be made of a fluoropolymer, specifically of Spectralon, thereby specifically providing a standardized reflectance. The reflective element specifically may have a reflectance of at least 99 % over a spectral range of 1100 nm to 2500 nm. The reflective element specifically may have diffusive properties.

As outlined above, the sample space specifically may have at least one sidewall, fully or partial ly surrounding the sample space. The reflective element may form at least a part of a bottom of the sample space. The side wall may contain at least one opening axially spaced apart from the bottom, such that the sample space is fillable with a liquid sample from the bottom up to the opening, thereby defining a measurement chamber within the sample space fillable with liquid sample. Thus, the sample space may contain an overflow or level drain in the form of the at least one opening which defines a measurement chamber having a precise volume, since the measurement chamber may be fillable precisely up to the height of the overflow or level drain. Thereby, the length of an optical path within the measurement chamber of the sample space and/or within the sample itself may be designed in a well-defined manner, which is highly favor able for spectroscopic purposes. Further, the length of the optical path within the measurement chamber of the sample space and/or within the sample itself may be designed in a manner in dependent from the filling level of the container itself, since, e.g. by temporarily tilting the con tainer, the sample space may be fully filled with sample, independent from the filling level of the container. Specifically, the measurement chamber may have a length, specifically an optical path length in absence of the liquid chemical and/or an axial length, of no more than 60 mm, specifically of no more than 50 mm, more specifically an optical path length of 500 pm to 50 mm, more specifically of 100 pm to 20 mm, more specifically of 200 pm to 8 mm.

The container lid may further comprise at least one filling element configured to fill the sample space and, specifically, the measurement chamber of the sample space, with liquid sample from the container. The term“filling element” is a broad term and is to be given its ordinary and cus- tomary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to an element, a device or a combination of devices configured for transferring liquid sample from the container into the sample space and, specifically, into the measurement chamber. For transfer of the liquid sam ple, the filling element may contain an arbitrary transfer element, such as a pipe, a pipette, a movable sampling device or the like. Specifically, the filling element may be configured to fill the sample space with liquid sample from the container without opening the container lid. Thus, as an example, the filling element may contain at least one actuator protruding through the con tainer lid which may be actuated by a user from outside the container, without the necessity of opening the lid. As an example, an end portion of a tube or pipette may protrude through the lid and may be actuated by the user, such as from a pickup position into a transfer position. Thus, generally, the filling element may be movable from a pickup position in which the filling element is positioned for picking up sample from the container and a transfer position in which the filling element is positioned for transferring the sample into the sample space. As an example, a pi pette may be moved up and down inside the container, e.g. by handling an end portion of the pipette, thereby picking up sample when a tip of the pipette is in a lower, pickup position within a main storage space within the container inside the liquid chemical, and subsequently pulling up the pipette into an upper, transfer position within the sample space, and delivering the sample from the pipette into the sample space. The filling element specifically may comprise a dosing device for pickup of a predefined amount of sample. Thus, as outlined above, the filling element specifically may comprise at least one pipette.

In a further aspect of the present invention, a chemical container system is disclosed. The chemical container system specifically may be designed for use with liquid chemicals as out lined above. The chemical container system comprises:

at least one container lid according to the present invention, such as disclosed in any one of the embodiments described above and/or in any one of the embodiments described in further detail below; and

a chemical container having an interior space and at least one container-side me chanical connection element.

The container lid is mechanically connectable to the chemical container by using the mechani cal connection element and the container-side mechanical connection element.

The container-side connection element of the chemical container specifically may form a coun terpart to the mechanical connection element of the container lid. The container-side connection element of the chemical container specifically may comprise at least one thread, more specifi cally at least one male thread.

As outlined above, the chemical container specifically may comprise at least one element se lected from the group consisting of: a barrel; a canister; a bottle. For further details of the chem ical container, reference may be made to the disclosure given above in the context of the con tainer lid. In a further aspect of the present invention, a spectrometer system is disclosed. The spectrome ter system comprises:

at least one spectrometer device configured for analyzing light from at least one sample; and

at least one container lid according to the present invention, such as disclosed in any one of the embodiments described above and/or in any one of the embodiments described in further detail below.

The spectrometer device specifically may be reversibly connectable to the container lid. The spectrometer system may further comprise at least one chemical container having an interior space and at least one container-side mechanical connection element, wherein the container lid is mechanically connectable to the chemical container by using the mechanical connection ele ment and the container-side mechanical connection element. The spectrometer device specifi cally may be a mobile spectrometer device, more specifically a hand-held spectrometer device.

The spectrometer device specifically may comprise:

at least one housing having at least one entrance window;

at least one wavelength-selective element configured for separating incident light in to a spectrum of constituent wavelengths, the wavelength-selective element being disposed within the housing; and

at least one detector device configured for detecting at least a portion of the constit uent wavelengths, the detector device being disposed within the housing.

The term“housing” is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning.

The term specifically may refer, without limitation, to an element or a combination of elements which are configured for fully or partially surrounding and/or providing mechanical cover for one or more other elements. Thus, as an example, the housing may be or may comprise at least one rigid housing, such as at least one rigid housing made of at least one of a plastic material or a metal. Similarly, the term“entrance window” is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to an opening in the housing which is unfilled or which is filled with at least one optically transparent material, specif ically in the above-mentioned sense and/or in one or more of the above-mentioned spectral ranges. The entrance window specifically may comprise a transparent opening and/or early transparent window within the housing.

The term“wavelength-selective element” is a broad term and is to be given its ordinary and cus tomary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to an arbitrary element or a combination of elements suitable for one or more of transmitting, reflecting, deflecting or scattering light in a wavelength-dependent manner. The wavelength-selective element, as an example, may be or may comprise at least one element selected from the group consisting of: an optical grating; an optical prism; a wavelength selective optical filter, specifically a length variable filter.

The term“detector device” is a broad term and is to be given its ordinary and customary mean ing to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to an arbitrary device or combina tion of devices capable of monitoring and/or recording at least one physical, chemical or biologi cal parameter. Specifically, the detector device may comprise at least one optical detector de vice, such as a device configured for recording and/or monitoring incident light. The detector device specifically may, thus, be or may comprise an optical detector element, such as at least one optical sensor, e.g. an optical semiconductor sensor. As an example, the detector device may comprise at least one photodetector such as at least one CCD or CMOS device. The de tector device may, preferably, be designed for detecting electromagnetic radiation over a con siderably wide spectral range, wherein the infrared (IR) spectral range may particularly be pre ferred. Herein, indium gallium arsenide (InGaAs) may especially, be selected for the photocon- ductive layer within the sensor region of the optical sensor for wavelengths up to 2.6 pm, indium arsenide (InAs) for wavelengths up to 3.1 pm, lead sulfide (PbS) for wavelengths up to 3.5 pm, lead selenide (PbSe) for wavelengths up to 5 pm, indium antimonide (InSb) for wavelengths up to 5.5 pm; and mercury cadmium telluride (MCT, HgCdTe) for wavelengths up 16 pm. In a par ticularly preferred embodiment of the present invention, the detector device may comprise a sulfide chalcogenide, preferably lead sulfide (PbS), a selenide chalcogenide, preferably lead selenide (PbSe), a ternary chalcogenide, preferably lead sulfoselenide (PbSSe), or another ap propriate material. Infrared optical sensors which may be used for the detector device may be commercially available infrared optical sensors, such as infrared optical sensors commercially available under the brand name Hertzstueck™ from trinamiX GmbH, D-67056 Ludwigshafen am Rhein, Germany. The detector device specifically may comprise at least one detector array comprising a plurality of pixelated sensors, wherein each of the pixelated sensors is configured to detect at least a portion of at least one of the constituent wavelengths.

The optical window element of the container lid, when the spectrometer device is coupled to the container lid, specifically may be disposed in front of the entrance window of the spectrometer device. Thus, the light from the interior space of the container may pass through the optical window element of the container lid and the entrance window of the spectrometer device into an interior space inside the housing of the spectrometer device.

The spectrometer device may further comprise at least one optical element configured for re ceiving incident light from a sample and transferring the incident light to the wavelength- selective element. The optical element, as an example, may be or may comprise at least one optical element selected from the group consisting of: an optical concentrator device; a lens; a mirror; a prism; a waveguide.

The spectrometer device further comprises at least one illumination source configured for illu minating a liquid sample inside the sample space, specifically inside the measurement cham- ber, of the container lid. The illumination source, as an example, may be disposed inside the housing and/or on an outer side of the housing, e.g. in proximity to the entrance window of the housing. The illumination source, as an example, may comprise at least one element selected from the group consisting of: an LED, a laser, an incandescent lamp. The illumination source specifically may be configured for illuminating the liquid through the optical window element.

The spectrometer system may further comprise at least one evaluation unit configured for de termining information related to at least one spectral property of the sample by evaluating at least one detector signal provided by the detector device. The evaluation unit, as an example, may comprise at least one processor configured for performing the evaluation of the detector signal. The evaluation unit, as an example, may fully or partially be disposed within the housing and/or may fully or partially be disposed outside the housing. The evaluation units may be inte grated into the spectrometer device or may be separate from the spectrometer device, such as by being connected to the spectrometer device via at least one wire-bound or wireless interface.

In a further aspect of the present invention, a use of one or more of the container lid according to the present invention, the container system according to the present invention or the spec trometer system according to the present invention is disclosed, for a purpose of use, selected from the group consisting of: an identification of a liquid contained within the container; an au thentication of a liquid contained within the container; a detection of an unwanted manipulation of a liquid contained within the container; a verification of a composition of a liquid contained within the container; a pollution monitoring application; an industrial process monitoring applica tion; a chemical process monitoring application; a food processing process monitoring applica tion; a water quality monitoring application; an air quality monitoring application; a quality control application; a gas analytics application; a chemical sensing application; a customs control appli cation; an anti-counterfeiting application; a tax control application, specifically for tax control of fuels; a medical application.

In still a further aspect of the present invention, a method for spectroscopic analysis of at least one sample is disclosed, specifically of at least one liquid sample. The method comprises the following method steps, which may be performed in the given order. A different order is also possible, including the option of performing one or more of the method steps fully or partially simultaneously. Further, one or more of the method steps may be performed in a repeated fash ion. The method may comprise additional steps which are not listed. The method comprises the following steps:

I. providing the spectrometer system according to the present invention, such as de scribed in any one of the preceding embodiments and/or as described in any one of the embodiments disclosed in further detail below;

II. connecting the spectrometer device to the container lid; and

III. evaluating at least one detector signal provided by the spectrometer device.

The devices and methods according to the present invention provide a large number of ad vantages over known devices and methods. Thus, the invention generally allows for a conven- ient analysis of chemical substances, such as liquid chemicals, even in the field. Thus, besides the identification and/or authentication of products, the invention e.g. may be applied to the de tection of illegally diluted products, manipulated products, unlicensed products, counterfeiting or other illegal products or actions. The invention specifically may apply means of mobile spec troscopy. The product may be analyzed, authenticated or verified e.g. by customers, sales per sons, field inspectors, customs officers, tax control officers, pharmacists or medical healthcare employees, by using the means and methods according to the present invention. The invention generally may allow for designing the containment of certain products for a convenient analysis of the product with a mobile spectrometer. The invention specifically may allow for an analysis or product identification or product verification without opening the containment. The invention further specifically may allow for avoiding the person performing the identification, verification or analysis getting in contact with the substance.

The invention specifically may allow for integrating a measurement setup or a part thereof into the container lid. The container lid comprises the optical window element through which radia tion for the measurement may enter and/or exit the container. The container lid further compris es the at least one reflective element which may be configured to provide for a reflectance standard. The reflective element may reflect radiation entering the container through the optical window element back to a measurement device, such as back to the spectroscopic device. The container lid further may comprise a spacer element, which may ensure a well-defined distance between the optical window element and the reflective element. Thus, the spacer element may ensure a given distance comparable to a standard cuvette in I R spectroscopy. As an example, the distance may be 1 mm to 4 mm. Other designs, however, are feasible, too. Further, the con tainer lid comprises the sample space, which may comprise the measurement chamber, which specifically may be designed to have a specific and well-defined amount of liquid chemical be tween the optical window element and the reflective element.

The above-mentioned measurement chamber inside the sample space may contain a defined volume of the sample, specifically of the liquid sample. Thus, the measurement chamber may also be used for other purposes than analysis, authentication or verification by optical means. Thus, as an example, the measurement chamber may also be used for taking samples from the chemical substance contained within the container. Thus, as an example, the container lid or the measurement chamber may also be usable as a dosing means. The dosing means may be for measuring a specified volume of the chemical substance or more such as the liquid chemical inside the container, preferably without opening the container, such as in order to then remove the specified volume of liquid from the container for further use.

The invention specifically may allow for measurements of the chemical substance inside the container without the necessity of opening the container. Thus, the contents of the container may be one or more of analyzed, authenticated or verified without opening the container.

The optical window element specifically may be made of a material that is at least partially transparent in the infrared range. Additionally or alternatively, the optical window element may also be transparent in the visible spectral range, e.g. for a visual inspection of the measurement path. The reflective element, such as the reflective element providing for a reflectance standard, may, as an example, comprise at least one metallized surface, optionally covered with at least one plastic material for material compatibility, e.g. with the chemical substance contained in the container. Additionally or alternatively, the reflective element may contain a fluorinated polymer, such as a Teflon or PTFE disc, or the like.

The container lid may further comprise means for indicating whether the container has been opened. Thus, as an example, the container lid may also contain a breakable seal which is bro ken and/or irreversibly modified when opening the container and/or when removing the contain er lid from the container.

Summarizing and without excluding further possible embodiments, the following embodiments may be envisaged:

Embodiment 1 : A container lid for closure of a chemical container, specifically for liquid chemi cals, comprising

a lid body, wherein an optical window element is disposed within the lid body;

at least one reflective element positioned such that, when the container lid is me chanically connected to the chemical container, the reflective element at least par tially is positioned in an interior space of the chemical container; and

at least one sample space fluidically connected to the interior space of the chemical container when the container lid is mechanically connected to the chemical contain er, wherein the sample space is located in between the reflective element and the optical window element.

Embodiment 2: The container lid according to the preceding embodiment, wherein the mechan ical connection element comprises at least one element selected from the group consisting of: a thread, specifically an internal screw thread; a flange; a clip.

Embodiment 3: The container lid according to any one of the preceding embodiments, wherein the optical window element is made of at least one plastic material.

Embodiment 4: The container lid according to the preceding embodiment, wherein the plastic material of the optical window element comprises at least one plastic material selected from the group consisting of: a polyolefin, specifically polypropylene or polyethylene; a polyester, specifi cally polyethylene terephthalate; a fluorinated polymer, specifically polytetrafluoroethylene; a chlorinated polymer, specifically polyvinylchloride; a polystyrene; a polyamide, specifically PA6; a polyacrylate, specifically poly(methyl methacrylate). Embodiment 5: The container lid according to any one of the preceding embodiments, wherein the optical window element has a thickness of 3 pm to 3 mm, specifically a thickness of 5 pm to 1 mm, more specifically a thickness of 10 pm to 500 pm.

Embodiment 6: The container lid according to any one of the preceding embodiments, wherein the optical window element is made of a material having a transmittance of at least 10 % over the spectral range of 1400 nm to 2000 nm or even over the spectral range of 1300 nm to 2500 nm.

Embodiment 7: The container lid according to the preceding embodiment, wherein the transmit tance of the optical window element is at least 30% over the spectral range of 1400 nm to 2000 nm and more preferably over the spectral range of 1300 nm to 2500 nm.

Embodiment 8: The container lid according to any one of the preceding embodiments, wherein the transmittance of the optical window element is at least 10% for every wavelength in the spectral range of 1400 nm to 2000 nm.

Embodiment 9: The container lid according to any one of the preceding embodiments, wherein the container lid further comprises at least one spacer element configured for separating the reflective element from the lid body and for holding the reflective element.

Embodiment 10: The container lid according to the preceding embodiment, wherein the spacer element protrudes from the lid body into the interior space of the chemical container when the container lid is mechanically connected to the chemical container.

Embodiment 1 1 : The container lid according to any one of the preceding embodiments, wherein a distance between the optical window element and the reflective element is 500 pm to 50 mm, specifically 100 pm to 20 mm, more specifically 200 pm to 8 mm.

Embodiment 12: The container lid according to any one of the preceding embodiments, wherein the container lid further comprises at least one spectrometer connection element configured for connecting the lid body to at least one spectrometer device located outside the interior space of the chemical container.

Embodiment 13: The container lid according to the preceding embodiment, wherein the spec trometer connection element and the mechanical connection element are located on opposite sides of the lid body.

Embodiment 14: The container lid according to any one of the two preceding embodiments, wherein the spectrometer connection element fully or partially surrounds the optical window element. Embodiment 15: The container lid according to any one of the three preceding embodiments, wherein the spectrometer connection element comprises at least one element selected from the group consisting of: a magnet, specifically a ring-shaped magnet surrounding the optical win dow element; a thread, specifically a male thread; an adapter element for connecting the spec trometer device to the lid body, specifically a tubular adapter element; a clip.

Embodiment 16: The container lid according to any one of the preceding embodiments, wherein the lid body has a cylindrical shape.

Embodiment 17: The container lid according to the preceding embodiments, wherein the optical window element and the reflective element are located on a cylinder axis of the lid body.

Embodiment 18: The container lid according to any one of the preceding embodiments, wherein the reflective element at least partially is made of at least one of: a plastic material; a metal.

Embodiment 19: The container lid according to the preceding embodiments, wherein the reflec tive element at least partially is made of a fluoropolymer, specifically of Spectralon.

Embodiment 20: The container lid according to any one of the preceding embodiments, wherein the reflective element has a reflectance of at least 99 % over a spectral range of 1 100 nm to 2500 nm.

Embodiment 21 : The container lid according to any one of the preceding embodiments, wherein the reflective element has diffusive properties.

Embodiment 22: The container lid according to any one of the preceding embodiments, wherein the sample space has at least one sidewall, wherein the reflective element forms at least a part of a bottom of the sample space, wherein the side wall contains at least one opening axially spaced apart from the bottom, such that the sample space is fillable with a liquid sample from the bottom up to the opening, thereby defining a measurement chamber within the sample space fillable with liquid sample.

Embodiment 23: The container lid according to the preceding claim, wherein the measurement chamber has a length of no more than 60 mm, specifically of no more than 50 mm, more specif ically an optical path length of 500 pm to 50 mm, more specifically of 100 pm to 20 mm, more specifically of 200 pm to 8 mm.

Embodiment 24: The container lid according to any one of the preceding embodiments, further comprising at least one filling element configured to fill the sample space with liquid sample from the chemical container. Embodiment 25: The container lid according to the preceding embodiment, wherein the filling element is configured to fill the sample space with liquid sample from the chemical container without opening the container lid.

Embodiment 26: The container lid according to any one of the two preceding embodiments, wherein the filling element is movable from a pickup position in which the filling element is posi tioned for picking up sample from the container and a transfer position in which the filling ele ment is positioned for transferring the sample into the sample space.

Embodiment 27: The container lid according to any one of the three preceding embodiments, wherein the filling element comprises a dosing device for pickup of a predefined amount of sample.

Embodiment 28: The container lid according to any one of the four preceding embodiments, wherein the filling element comprises at least one pipette.

Embodiment 29: A chemical container system, specifically for liquid chemicals, comprising:

at least one container lid according to any one of the preceding embodiments; a chemical container having an interior space and at least one container-side me chanical connection element,

wherein the container lid is mechanically connectable to the chemical container by using the mechanical connection element and the container-side mechanical connection element.

Embodiment 30: The chemical container system according to the preceding embodiment, wherein the container-side connection element of the chemical container comprises at least one thread, specifically at least one male thread.

Embodiment 31 : The chemical container system according to any one of the two preceding em bodiments, wherein the chemical container comprises at least one element selected from the group consisting of: bottle; a barrel; a canister; a bottle.

Embodiment 32: A spectrometer system, comprising:

at least one container lid according to any one of the preceding embodiments refer ring to a container lid.

Embodiment 33: The spectrometer system according to the preceding embodiment, wherein the spectrometer device is reversibly connectable to the container lid.

Embodiment 34: The spectrometer system according to any one of the two preceding embodi ments, wherein the spectrometer system further comprises at least one chemical container hav ing an interior space and at least one container-side mechanical connection element, wherein the container lid is mechanically connectable to the chemical container by using the mechanical connection element and the container-side mechanical connection element.

Embodiment 35: The spectrometer system according to any one of the preceding embodiments referring to a spectrometer system, wherein the spectrometer device is a mobile spectrometer device, specifically a hand-held spectrometer device.

Embodiment 36: The spectrometer system according to any one of the preceding embodiments referring to a spectrometer system, wherein the spectrometer device comprises:

at least one housing having at least one entrance window;

Embodiment 37: The spectrometer system according to the preceding embodiment, wherein the optical window element of the container lid, when the spectrometer device is coupled to the con tainer lid, is disposed in front of the entrance window of the spectrometer device.

Embodiment 38: The spectrometer system according to any one of the two preceding embodi ments, wherein the detector device comprises at least one detector array comprising a plurality of pixelated sensors, wherein each of the pixelated sensors is configured to detect at least a portion of at least one of the constituent wavelengths.

Embodiment 39: The spectrometer system according to any one of the three preceding embod iments, wherein the wavelength-selective element comprises at least one element selected from the group consisting of: an optical grating; an optical prism; a wavelength selective optical filter, specifically a length variable filter.

Embodiment 40: The spectrometer system according to any one of the four preceding embodi ments, wherein the spectrometer device further comprises at least one optical element config ured for receiving incident light from a sample and transferring the incident light to the wave- length-selective element.

Embodiment 41 : The spectrometer system according to any one of the preceding embodiments referring to a spectrometer system, wherein the spectrometer device further comprises an illu mination source configured for illuminating a liquid sample inside the sample space of the con tainer lid.

Embodiment 42: The spectrometer system according to the preceding embodiment, wherein the illumination source comprises at least one element selected from the group consisting of: an LED, a laser, an incandescent lamp. Embodiment 43: The spectrometer system according to any one of the two preceding embodi ments, wherein the illumination source is configured for illuminating the liquid through the optical window element.

Embodiment 44: The spectrometer system according to any one of the preceding embodiments referring to a spectrometer system, further comprising at least one evaluation unit configured for determining information related to at least one spectral property of the sample by evaluating at least one detector signal provided by the detector device.

Embodiment 45: A use of one or more of the container lid according to any one of the preceding embodiments referring to a container lid, the container system according to any one of the pre ceding embodiments referring to a container system or the spectrometer system according to any one of the preceding embodiments referring to a container system, for a purpose of use, selected from the group consisting of: an identification of a liquid contained within the container; an authentication of a liquid contained within the container; a detection of an unwanted manipu lation of a liquid contained within the container; a verification of a composition of a liquid con tained within the container; a pollution monitoring application; an industrial process monitoring application; a chemical process monitoring application; a food processing process monitoring application; a water quality monitoring application; an air quality monitoring application; a quality control application; a gas analytics application; a chemical sensing application; a customs con trol application; an anti-counterfeiting application; a tax control application, specifically for tax control of fuels; a medical application.

Embodiment 46: A method for spectroscopic analysis of at least one sample, specifically at least one liquid sample, the method comprising:

I. providing the spectrometer system according to any one of the preceding embodi ments referring to a spectrometer system;

II. connecting the spectrometer device to the container lid; and

Short description of the Figures

Further optional features and embodiments will be disclosed in more detail in the subsequent description of embodiments, preferably in conjunction with the dependent claims. Therein, the respective optional features may be realized in an isolated fashion as well as in any arbitrary feasible combination, as the skilled person will realize. The scope of the invention is not restrict ed by the preferred embodiments. The embodiments are schematically depicted in the Figures. Therein, identical reference numbers in these Figures refer to identical or functionally compara ble elements.

In the Figures: Figure 1 shows a first embodiment of a container lid, of a chemical container system and of a spectrometer system in a cross-sectional view;

Figure 2 shows a second embodiment of a container lid, of a chemical container system and of a spectrometer system in a cross-sectional view;

Figure 3 shows a third embodiment of a container lid, of a chemical container system and of a spectrometer system in a cross-sectional view; and

Figures 4 to 6 show absorbance curves of various plastic materials.

Detailed description of the embodiments

In Figures 1 -3, three different embodiments of a container lid 1 10, of a chemical container sys tem 1 12 comprising the container lid 1 10 and a chemical container 1 14, as well as of a spec trometer system 1 16 comprising a spectrometer device 1 18 and the container lid 1 10 are dis closed in cross-sectional views.

In a first embodiment shown in Fig. 1 , the chemical container 1 14, as an example, may com prise a container wall 120 and optionally a container neck 122. Thus, as an example, the chem ical container 1 14 may have the shape of a bottle or a canister. Other shapes, however, are feasible. The chemical container 1 14 comprises an interior space 124 which may be filled e.g. with a liquid chemical 126, e.g. up to a filling level 128.

The container lid 1 10 comprises a lid body 130 with an optical window element 132 disposed within the lid body 130. The container lid 1 10 further comprises at least one mechanical connec tion element 134 for mechanically connecting the container lid 1 10 to the chemical container 1 14, e.g. to the container neck 122. As an example and as can be seen in Fig. 1 , the mechani cal connection element 134 may comprise a rim 136 which may engage with the container neck 122, e.g. by a force-fit and/or by a form-fit connection. As an example, the mechanical connec tion element 134 may comprise a thread which may engage with a thread of the container neck 122. Other means of connection, however, are feasible, such as press-fit connections, crimping or the like.

The lid body 130, as an example, may be made of one or more of a plastic material, a metal or a ceramic material. The optical window element 134, as an example, may be disposed within an opening 138 which preferably is centrally disposed in the lid body 130. The optical window ele ment 134, as an example, may fully or partially be made of a material, such as a glassy material and/or a plastic material, which is transparent in one or more of the visible spectral range, the infrared spectral range or the ultraviolet spectral range. Specifically, the transmittance of the optical window element 134 may be at least 10% over the spectral range of 1400 nm to 2000 nm. As an example, the optical window element 134 may have a thickness of a few microns to 1 mm, such as a thickness of 50 miti to 1 mm. Even though these values are specifically suitable specifically for infrared spectroscopy, other embodiments, dimensions and materials for the op tical window element 134 may be feasible.

The container lid 110 further comprises at least one reflective element 140. The reflective ele ment 140, as an example, may be connected to the lid body 130 by at least one spacer element 142 which may be configured for holding the reflective element 140 and for separating the re flective element 140 from the lid body 130. The reflective element 140 is configured such that, when the container lid 110 is mechanically connected to the chemical container 114, the reflec tive element 140 is positioned within the interior space 124 of the chemical container 114.

Thereby, a sample space 144 is formed in between the reflective element 140 and the optical window element 132. The sample space 144 is fluidically connected to the interior space 124 of the chemical container 1 14 and, thus, as can be seen in Fig. 1 , may be filled with liquid chemi cal 126.

The reflective element 140 may provide for a reflectance standard. As an example, at least one reflective plastic material may be used, e.g. a white plastic material, such as Spectralon. Addi tionally or alternatively, one or more metallic reflectors and/or dielectric reflectors may be used, such as by using a dielectric and/or metallic multilayer setup. The reflective element 140 may be configured for directed reflection and/or for diffusive reflection. Generally, the light 146 entering the chemical container 1 14 and the sample space 144 through the optical window element 132 may pass through the sample space 144 and the liquid chemical 126 contained therein and may be reflected backwards, as can be seen in Fig. 1.

As outlined above, the spectrometer system 116 further comprises the spectrometer device 1 18. The spectrometer device 1 18, as an example, may be reversibly connected to the contain er lid 1 10 by a removable spectrometer connection element 148, such as by a tubular connec tion element. The spectrometer device 118 may comprise a housing 150 having an entrance window 152 which may be or may comprise an opening and/or which may be or may comprise an optical element such as a lens. Inside the housing 150, at least one detector device 154 may be disposed, such as at least one array of photosensitive elements, e.g. a CCD and/or a CMOS array. Further, inside the housing 150 and in between the entrance window 152 and the detec tor device 154, at least one wavelength-selective element 156 may be disposed, such as for separating incident light into a spectrum of constituent wavelengths, such as one or more wave- length-selective filters, prisms, optical gratings or the like.

In Fig. 2, a modification of the setup shown in Fig. 1 is disclosed. For most of the details, refer ence may be made to the setup shown in Fig. 1. The embodiment of Fig. 2, however, differs from the embodiment shown in Fig. 1 in the design of the spacer element 142 and the sample space 144. Thus, in the embodiment of Fig. 2, the reflective element 140 forms a bottom of the sample space 144. The sample space 144 further, however, comprises at least one sidewall 158, which at least partially may be formed by the spacer element 142 which separates the re flective element 140 from the lid body 130 and which defines the positioning of the reflective element 140 within the chemical container 114. The sidewall 158, however, comprises at least one opening 160 axially spaced apart from the bottom of the sample space 144. Thus, the sam ple space 144 is fillable with liquid chemical 126 from the bottom formed by the reflective ele ment 142 up to the rim of the opening 160. Consequently, within the sample space 144, a measurement chamber 162 is defined which is fillable with a liquid sample of the liquid chemical 126. As can be seen in Fig. 2, the filling level of the liquid sample may be different from the fill ing level in the remaining interior space 124 of the chemical container 114. By providing the at least one opening 160, which may act as an overflow, a well-defined volume and/or optical path length of liquid sample within the measurement chamber 162 may be provided, such that the light 146 passes through a well-defined thickness of liquid sample before being reflected to the spectrometer device 118. The measurement chamber 162 may be filled e.g. by tilting the chem ical container 114, thereby allowing for liquid chemical 126 to enter the measurement chamber 162.

In Fig. 3, a modification of the embodiment of Fig. 2 is shown. The embodiment widely corre sponds to the embodiment of Fig. 2, so reference may be made to the description given above. Still, in order to simplify the filling of the measurement chamber 162 within the sample space 144 with liquid sample from the interior space 124 of the chemical container 1 14, at least one filling element 164 is provided. The filling element 164 specifically may be configured as a dos ing device 166. The filling element 164 may be configured to fill the sample space 144, specifi cally the measurement chamber 162, with liquid sample without opening the container lid 1 10. Thus, as an example, the dosing device 166 may comprise a pipette, which may be vertically movable in the setup of Fig. 3. Thus, in a position shown in Fig. 3, which may also be referred to as a pickup position, the filling element 164, specifically a mouth 168 of the pipette, may be lo cated inside the liquid chemical 126 and may take up liquid sample. Subsequently, the filling element 164 may be moved vertically upwards in Fig. 3, until the mouth 168 is located within the measurement chamber 162 and may transfer the liquid sample into the measurement chamber 162. Thus, the filling of the measurement chamber 162 and/or of the sample space 144 without opening the container lid 1 10 may be simplified.

In Figures 4 to 6, absorption measurements of various plastic materials are shown, which may be used for the optical window element 132. Therein, besides the materials, the thickness of the plastic material is also varied. Each of the graphs in these Figures shows, on the horizontal ax is, the wave number k = l ¹, given in cm ¹. On the vertical axis, the dimensionless absorbance A is given, which is the negative decadic logarithm of the transmittance T as defined above, i.e. A=-logioT. For the sake of clarity and simplification, several wavelengths are marked on the horizontal axis, as well as specific transmittances on the vertical axis.

In Fig. 4, absorbance curves for various materials having a similar thickness in the range of 23 pm to 30 pm are shown. Therein, PTFE denotes the fluorinated polymer polytetrafluoroethylene, PS denotes polystyrene, PET denotes polyethylene terephthalate, PELD denotes low density polyethylene, and PA6 denotes polycaprolactam, also referred to as Nylon 6. Firstly, as can be seen, all of these materials generally have a transmittance of at least 80%, i.e. an absorbance of less than 0.1 , over the spectral range of 1400 nm to 2000 nm. For wave lengths above 2.0 pm, higher absorption peaks may be noted, which severely decrease trans mission. Since, according to the Beer-Lambert law, the absorbance is roughly proportional to the thickness of the material, for all of these materials the layer thickness may be increased by a factor of 10, and the absorbance would still be below 1 over the named spectral range, i.e. the transmittance would still exceed 10%.

As can further be seen in these curves, the absorbance for these low thicknesses is subject to interference effects, which leads to periodic and sinusoidal absorbance curves as a function of the wave number. These interference effects are mainly due to the fact that the layer thickness is in the range of the wavelength and, at least partially, differs from the wavelength by no more than an order of magnitude. These interference effects, when using the plastic materials for spectroscopic purposes, may either be corrected electronically or mathematically, e.g. by filter ing these periodic signals. Additionally or alternatively, however, interference effects may be suppressed by optical means, such as by using a roughened surface for the optical window el ement 138 and/or by using anti-reflection coatings on the optical window element. For higher layer thicknesses, the interference effects will vanish. Additionally or alternatively, the material of the optical window 138 element may be chosen to have a refractive index close to the sample medium, e.g. a refractive index deviating by no more than 0.1 from the refractive index of the sample to be analyzed. As an example, specifically for aqueous media, the plastic material of the optical window element 138 may be chosen to have a refractive index close to water, e.g. having a refractive index of 1.33 ± 0.1. As an example, PTFE has a refractive index of 1.36 which is close to the refractive index of water of 1.33. Flence, PTFE may be a suitable material for measuring samples with a high water content.

As a further result of the curves shown in Fig. 4, it turns out that fluorinated polymers such as PTFE provide for high transparency of the optical window element 132. Thus, over the full spec tral range of 1.4 pm to 2.5 pm, which is of high interest for infrared spectroscopy, PTFE shows a transmittance of more than 95% for a layer thickness of 25 pm. Specifically, even in the range of 2.0 pm to 2.5 pm, in which the other polymers exhibit a clear absorption peak, PTFE has a high transmittance of more than 95%. Consequently, since PTFE is also known as a highly inert ma terial which is suited to sustain even aggressive sample materials, fluorinated polymers such as PTFE turn out to be well-suited candidate materials for the optical window element 132. Since PTFE has an absorbance of below 0.02, corresponding to a transmittance of more than 95%, and since the absorbance is roughly proportional to the thickness of the material, PTFE may even be used at a thickness of approximately 125 pm, by still having an absorbance of less than 0.1 , corresponding to a transmittance of more than 80%. Or, alternatively, PTFE may even be used up to a thickness of 650 pm, still having a transmittance of more than 30%.

In Fig. 5, thickness dependency of the absorbance is shown for polypropylene, denoted as PP, for thicknesses of 4 pm to 50 pm. According to the Beer-Lambert law, since the absorbance is a logarithmic figure, the absorbance should be roughly proportional to the thickness of the plastic material, which is approximately valid for these curves. These effects, however, are superim posed by other optical effects, such as the above-mentioned interference effects, effects of ma terial inhomogeneity or surface effects. Still, as can be seen, at least for thicknesses of approx imately up to 12 pm, polypropylene has a transmittance of more than 80% in the wavelength range of 1.4 pm to 2.5 pm.

In Fig. 6, finally, further materials are evaluated, including polypropylene, polycarbonate PC and high density polyethylene PEHD. As can be seen and as discussed above in the context of Fig. 5, polypropylene has a transmittance of more than 80% in the wavelength range of 1.4 pm to 2.5 pm. H igh density polyethylene, however, exhibits a high absorption peak. Again and as dis cussed above, interference effects are detected which may require correction by electron ic/mathematical means and/or by optical means.

List of reference numbers

110 container lid

112 chemical container system

114 chemical container

116 spectrometer system

118 spectrometer device

120 container wall

122 container neck

124 interior space

126 liquid chemical

128 filling level

130 lid body

132 optical window element

134 mechanical connection element

136 rim

138 opening

140 reflective element

142 spacer element

144 sample space

146 light

148 spectrometer connection element 150 housing

152 entrance window

154 detector

156 wavelength-selective element 158 side wall

160 opening

162 measurement chamber

164 filling element

166 dosing device

168 mouth

References

WO 95/27187 A1

US 2014/131578 A1

Claims

1. A container lid (1 10) for closure of a chemical container (114), specifically for liquid chem icals, comprising

a lid body (130), wherein an optical window element (132) is disposed within the lid body (130);

a mechanical connection element (134) for mechanically connecting the container lid (1 10) to the chemical container (114);

at least one reflective element (140) positioned such that, when the container lid (110) is mechanically connected to the chemical container (114), the reflective ele ment (140) at least partially is positioned in an interior space (124) of the chemical container (114); and

at least one sample space (144) fluidically connected to the interior space (124) of the chemical container (1 14) when the container lid (110) is mechanically connected to the chemical container (1 14), wherein the sample space (144) is located in be tween the reflective element (140) and the optical window element (132).

2. The container lid (110) according to the preceding claim, wherein the mechanical connec tion element (134) comprises at least one element selected from the group consisting of: a thread; a flange; a clip.

3. The container lid (1 10) according to any one of the preceding claims, wherein the optical window element (132) is made of at least one plastic material.

4. The container lid (110) according to the preceding claim, wherein the plastic material of the optical window element (132) comprises at least one plastic material selected from the group consisting of: a polyolefin, specifically polypropylene or polyethylene; a polyester, specifically polyethylene terephthalate; a fluorinated polymer, specifically polytetrafluoro- ethylene; a chlorinated polymer, specifically polyvinylchloride; a polystyrene; a polyamide, specifically PA6; a polyacrylate, specifically poly(methyl methacrylate).

5. The container lid (110) according to any one of the preceding claims, wherein the optical window element (132) has a thickness of 3 pm to 3 mm, specifically a thickness of 5 pm to 1 mm, more specifically a thickness of 10 pm to 500 pm.

6. The container lid (110) according to any one of the preceding claims, wherein the optical window element (132) is made of a material having a transmittance of at least 10 % over the spectral range of 1400 nm to 2000 nm, specifically having a transmittance of at least 30 % over the spectral range of 1400 nm to 2000 nm.

7. The container lid (110) according to any one of the preceding claims, wherein the trans mittance of the optical window element (132) is at least 10% for every wavelength in the spectral range of 1400 nm to 2000 nm.

8. The container lid (110) according to any one of the preceding claims, wherein the contain er lid (1 10) further comprises at least one spacer element (142) configured for separating the reflective element (140) from the lid body (130) and for holding the reflective element (140), wherein the spacer element (142) protrudes from the lid body (130) into the interior space (124) of the chemical container (1 14) when the container lid (110) is mechanically connected to the chemical container (114).

9. The container lid (110) according to any one of the preceding claims, wherein a distance between the optical window element (132) and the reflective element (140) is 500 pm to 50 mm, specifically 100 pm to 20 mm, more specifically 200 pm to 8 mm.

10. The container lid (110) according to any one of the preceding claims, wherein the contain er lid (1 10) further comprises at least one spectrometer connection element (148) config ured for connecting the lid body (130) to at least one spectrometer device (1 18) located outside the interior space (124) of the chemical container (1 14).

1 1. The container lid (110) according to any one of the preceding claims, wherein the reflec tive element (140) at least partially is made of at least one of: a plastic material; a metal.

12. The container lid (110) according to any one of the preceding claims, wherein the reflec tive element (140) has a reflectance of at least 99 % over a spectral range of 1 100 nm to 2500 nm.

13. The container lid (110) according to any one of the preceding claims, wherein the sample space (144) has at least one side wall (158), wherein the reflective element (140) forms at least a part of a bottom of the sample space (144), wherein the side wall (158) contains at least one opening (160) axially spaced apart from the bottom, such that the sample space (144) is fillable with a liquid sample from the bottom up to the opening (160), thereby de fining a measurement chamber (162) within the sample space (144) fillable with liquid sample.

14. The container lid (110) according to any one of the preceding claims, further comprising at least one filling element (164) configured to fill the sample space (144) with liquid sample from the chemical container (114).

15. A chemical container system (1 12), specifically for liquid chemicals, comprising:

at least one container lid (110) according to any one of the preceding claims;

a chemical container (1 14) having an interior space (124) and at least one contain er-side mechanical connection element,

wherein the container lid (110) is mechanically connectable to the chemical container (114) by using the mechanical connection element (134) and the container-side mechani cal connection element.

16. A spectrometer system, comprising:

at least one spectrometer device (1 18) configured for analyzing light from at least one sample; and

at least one container lid (110) according to any one of the preceding claims refer ring to a container lid (1 10).

17. A use of one or more of the container lid (1 10) according to any one of the preceding claims referring to a container lid (1 10), the container system according to any one of the preceding claims referring to a container system or the spectrometer system according to any one of the preceding claims referring to a container system, for a purpose of use, se lected from the group consisting of: an identification of a liquid contained within the con tainer; an authentication of a liquid contained within the container; a detection of an un wanted manipulation of a liquid contained within the container; a verification of a composi tion of a liquid contained within the container; a pollution monitoring application; an indus trial process monitoring application; a chemical process monitoring application; a food processing process monitoring application; a water quality monitoring application; an air quality monitoring application; a quality control application; a gas analytics application; a chemical sensing application; a customs control application; an anti-counterfeiting applica tion; a tax control application, specifically for tax control of fuels; a medical application.

18. A method for spectroscopic analysis of at least one sample, specifically at least one liquid sample, the method comprising:

I. providing the spectrometer system (1 16) according to any one of the preceding claims referring to a spectrometer system (1 16);

II. connecting the spectrometer device (1 18) to the container lid (1 10); and

III. evaluating at least one detector signal provided by the spectrometer device (1 18).