DK179468B1

DK179468B1 - A sampling pipette and cuvette, a method of carrying out spectroscopy and a device

Info

Publication number: DK179468B1
Application number: DKPA201770289A
Authority: DK
Inventors: Larsen Anders
Original assignee: Q-Interline A/S
Priority date: 2017-04-28
Filing date: 2017-04-28
Publication date: 2018-11-21
Also published as: DK201770289A1

Abstract

The present invention relates inter alis to a sampling pipette and cuvette comprising: a sample void formed in the sampling pipette and cuvette; the sample void being formed by a wall section(s) of the cuvette where said wall section(s) defines an outer surface of said cuvette; a tubular channel extendingfrom an inlet arranged at distal end of the sampling pipette and cuvette to the sample void; the wall section being made from an elastic material allowing deformation of the sample void and the wall section(s) comprising two optical windows being translucent to light with a wavelength in the range of UV,VIS and/or NIR with a transmission of at least 50%, said optical windows being opposite to each other, so as to allow light to be emitted through the sample void by passing through the optical windows.

Description

(¹⁹) DANMARK (10)

(12)

PATENTSKRIFT

Patent- og Varemærkestyrelsen

Int.CI.: B01L 3/02 (2006.01) G01N 1/10 (2006.01)

Ansøgningsnummer: PA 2017 70289

Indleveringsdato: 2017-04-28

Løbedag:2017-04-28

Aim. tilgængelig: 2018-10-29

Patentets meddelelse bkg. og publiceret den: 2018-11-21

Patenthaver:

Q-Interline A/S, Stengårdsvej 7 Lunderød, 4340 Tølløse, Danmark

Opfinder:

Anders Larsen, Marupvej 21,4340 Tølløse, Danmark

Fuldmægtig:

Plougmann Vingtoft A/S, Rued Langgaards Vej 8, 2300 København S, Danmark

Titel: A SAMPLING PIPETTE AND CUVETTE, A METHOD OF CARRYING OUTSPECTROSCOPY AND A DEVICE

Fremdragne publikationer:

US 2005/0101025 A1

US 2007/0081155 A1

DE 102007059167A1

US 2009/0306300 A1

WO 2008/134423 A1

Sammendrag:

Fortsættes...

Fig. 1 i

A SAMPLING PIPETTE AND CUVETTE, A METHOD OF CARRYING OUT SPECTROSCOPY AND A DEVICE

FIELD OF THE INVENTION

The present invention relates to a sampling pipette and cuvette comprising:

a sample void formed in the sampling pipette and cuvette; the sample void being formed by a wall section(s) of the cuvette where said wall section(s) defines an outer surface of said cuvette;

a tubular channel extending from an inlet arranged at distal end of the sampling pipette and cuvette to the sample void;

the wall section being made from an elastic material allowing deformation of the sample void and the wall section(s) comprising two optical windows being translucent to light with a wavelength in the range of UV,VIS and/or NIR with a transmission of at least 50%, said optical windows being opposite to each other, so as to allow light to be emitted through the sample void by passing through the optical windows.

The invention also relates to method of carrying out spectroscopy and a device using the sampling pipette and device for carrying out spectroscopy using a sampling pipette and cuvette.

BACKGROUND OF THE INVENTION

Liquid samples and in particular samples of dairy products are today inspected by use of FTIR spectroscopy (15021543:2006), during which a sample is sucked into FTIR equipment, heated and in some situations homogenised, and is introduced into a cuvette with an optical path length in the order of 35 micrometre. After inspection/measuring the equipment must undergo a time consuming and difficult cleaning procedure before a new sample can be investigated.

US2005/0101025 discloses a UV transmissible pipette time and UV absorbance measurement apparatus to provide a fast, convenient, economical and less contaminated means for measuring yields, purities and concentration of proteins, DNA, or RNA samples inside said pipette tip by UV absorbance analysis. The pipette tip is formed of plastic material transparent between 200 nm and 350 nm.

The pipette tip not only can be used for sampling and dispensing accurate liquid volumes, but can also be defiend as a photocell for absorbance measurement.

Since e.g. 100 samples are investigated per day, the present procedure may form a bottle-neck in an production facility.

Further, many samples has a high dry matter content rendering the material unsuited for being introduced in cuvette with an optical path length in the order of 35 micrometre.

Hence, an improved sampling and measurement device and method would be advantageous, and in particular a more efficient and/or reliable sampling and measuring would be advantageous.

SUMMARY OF THE INVENTION

Thus, the above described object and several other objects are intended to be obtained in a first aspect of the invention by providing a sampling pipette and cuvette preferably comprising:

UV, VIS and/or NIR preferably refers to

Ultra Violet light with a wavelength from 10 nm to 400 nm, Visual light with a wavelength from 400 nm to 700 nm, and/or Near Infra Red radiation with a wavelength from 700 nm to 2500 nm. where nm refers to nanometer.

In a second aspect, the invention relates to a method of carrying out spectroscopy, such as an absorbance spectrum, on a fluid sample, preferably being a liquid sample, the method preferably utilises a sampling pipette and cuvette according to the first aspect of the invention and the method preferably comprises arranging a fluid sample in the sample void;

compressing the wall section(s) of the sample void so as to define two opposite substantial parallel wall sections including the optical windows spaced apart with predetermined distance (d) to provide a preselected linear optical path length through the sample between the said two adjacent substantial parallel wall sections;

radiating light through the sampling sample void along the linear optical path length and record a spectrum for the sample (SS).

By preselected linear optical path as used herein is preferably meant that the optical path is predetermined, but variable due to the optical path may vary between samples.

By transmission of at least a certain percentage is preferably meant the amount of light that passes through the element considered. The amount is preferably considered through-out the spectrum of the light transmitted.

In a third aspect, the invention relates to device for presenting a sample to a spectrometer, the device preferably comprises:

a holder configured for receiving and holding a sampling pipette and cuvette according to the first aspect of the invention;

said holder comprising compressing elements being configured for compressing wall sections of said cuvette to provide two adjacent substantial parallel wall sections spaced apart with predetermined distance (d) to provide a predetermined linear optical path length through the sample cuvette through and between the said two adjacent substantial parallel wall sections;

transmitting optics arranged to radiate light along the linear optical path length, and receiving optics arranged to receive the light transmitted by the transmitting optics.

By a device for presenting a sample to a spectrometer is preferably meant a device in which the sampling pipette and cuvette can be hold and comprising the optics to allow the light to be analysed in order to obtain an absorbance spectrum, The device may form an element of spectrometer.

Further aspects and embodiments of the invention are presented in the following as well as in the accompanying patent claims.

BRIEF DESCRIPTION OF THE FIGURES

The present invention and in particular preferred embodiments thereof will now be described in more detail with reference to the accompanying figures. The figures show ways of implementing the present invention and are not to be construed as being limiting to other possible embodiments falling within the scope of the attached claim set.

Figure 1 schematically illustrates cross sectional views of sampling pipette and cuvette according to a first embodiment of the invention;

Figure 2 schematically illustrates cross sectional views of a sampling pipette and cuvette according to a second embodiment of the invention;

Figure 3 schematically illustrates measuring device utilizing a sampling pipette and cuvette according to the invention;

Figure 4 is a flow-chart of a method according to the invention.

DETAILED DESCRIPTION OF AN EMBODIMENT

Reference is made to fig. 1 schematically illustrating a first embodiment of a device labelled a sampling pipette and cuvette 1. As disclosed herein, the labelling sampling pipette and cuvette is used to at least indicate that the device may serve to purposes namely:

sampling that may translate into extracting an amount of fluid from a larger amount of fluid and by used as a cuvette during which the sample is exposed e.g. to light of certain wavelength(s) e.g. to provide an absorbance spectrum for the sample.

In the following sampling pipette and cuvette is abbreviated as SPAC

As illustrated in fig. 1, the SPAC comprises a sample void 2 formed in the SPAC. The sample void may be seen as a cavity provided inside the SPAC and is adapted to hold a sample of liquid or gas.

It is noted that the left hand side of fig. 1 is a vertical cross section of the SPAC whereas the right hand side (upper part) of fig. 1 shows two horizontal cross sections of the SPAC along lines A-A and B-B. The right hand side (lower part) of fig. 1 illustrates a cross section of the sample void 2 of the SPAC in a compressed state part (indicated by A'-A'); the sample void 2 being compressed so as to set an internal distance (preselected optical distance) d to a preselected distance during measurement as will be disclosed in greater details below.

Thus, the sample void 2 being formed by a wall sections 8 of the cuvette 1 where said wall sections 8 defines an outer surface of the SPAC. In fig. 1 left hand side, the dotted lined square illustrates a possible plane outer geometry of the SPAC, but the outer geometry so indicated may be dispensed so that the SPAC is formed by the elements 2, 4, 6, 9 indicated in fig. 1.

The SPAC comprises a tubular channel 4 extending from an inlet 5 arranged at distal end of the SPAC to the sample void 2. This tubular channel serves the purpose of a fluid connection between the sample void 2 and the exterior to the SPAC, that is fluid that is to be introduced into the sample void 2 flows into the tubular channel 4, through the tubular channel 4 and into the sample void 2.

Since the SPAC is to be used as a cuvette it is preferred that the distance d in fig. 1 can be altered or set and the wall sections 8 are accordingly made from an elastic material allowing deformation of the sample void 2. This also has the advantage that for the geometrical shape of the sample void 2 can be altered from e.g. as illustrated having a circular cross section to a cross section comprising two parallel, plane sections (see numeral 12).

Further, in order to allow light to pass through the sample void 2, the wall section 8 comprising two optical windows 13 being translucent to light with a wavelength in the range of UV,VIS, and/or NIR with a transmission of at least 50%. By optical windows 13 is preferably meant that there is a region of the wall section 8 having a transmission of at least 50%, wherein transmission is defined as the percentage of light passing through the wall section, e.g. the strength of the optical signal is decreased by 50%. The transmission may be determined as the transmission through the SPAC divided by the transmission in open beam. The optical windows 13 being opposite to each other, so as to allow light to be emitted through the sample void 2 by passing through the optical windows 13. In some embodiments, at least the sample 2 void is made from a single material, whereby the optical windows 13 is provided by the material forming the sample void 2 be translucent to light. In other embodiments, the optical windows 13 are made from a separate material.

As also illustrated in fig. 1 is a sample 11 which is shown to occupy only a part of the sample void. In the embodiment of fig. 1, the sample is shown to have a level inside the sample void 2 be levelled with the position of the outlet (the end) of the tubular channel 4. The region above the sample inside the sample void is labelled a head space 10 and this head space can be used to obtain a reference measurement to be used during e.g. an absorbance measurement; in such cases, the lights pass through the sample as well as though the head space which provides two measurements, and the measurement through the head space 11 can be used as a reference measurement.

Reference is made to fig. 2 schematically illustrating a further embodiment of an SPAC 1. In this embodiment, the SPAC 1 further comprising a reference void 3. As illustrated, the reference void 3 is a void being separated from the sample void 3, that is the reference void 3 is in not fluid communication with the sample void. It is noted that the reference void 3 may have a fluid connection (not shown) to the exterior of the SPAC so as to pressure balancing between the interior of the reference void 3 and the exterior e.g. due to compression and/or thermal changes.

Similarly to the sample void 2, the reference void 3 is formed by a wall section(s) 8 of the cuvette 1 where said wall section(s) 8 being made from an elastic material allowing deformation of the reference void 2. Further, the wall sections 8 of the reference void 3 comprising two optical windows 13 being translucent to light with a wavelength in the range of UV,VIS and/or NIR with a transmission of at least 50% and optical windows 13 are arranged opposite to each other, so as to allow light to be emitted through the reference void 2 by passing through the optical windows 13. In some embodiments, at least the reference 2 void is made from a single material, whereby the optical windows 13 is provided by the material forming the sample void 2 be translucent to light. In other embodiments, the optical windows 13 are made from a separate material.

Thus, one intention of the reference void 3 is to provide void being geometrically similar to, such as identical to, the sample void 2 but not holding a sample so as to provide a measurement similar to the measurement performed through the sample void but not containing the sample thereby defining a well-defined reference measurement.

In some embodiments, no connection is provided into the reference void 3 whereby the composition of the content - if not being evacuated - of the reference void 3 may be set to be a well-defined content. Thus, in some embodiments, the reference void 3 is a confined void, which may contain a preselected content. If the reference void 3 is not confined, it has a fluid communication opening allowing fluid communication out of/into the interior of the reference void 3 (not illustrated).

As illustrated in connection with the sample void 2, the reference void 3 may be compressed to provide a preselected optical distance d (not illustrated for reference void 3).

It may be preferred to eliminate errors in measurements arising from geometrical differences between the sample void and the reference void, and in such and other situation, the sample void 2 and the reference void 3 are substantially geometrically identical to each other. Further, and as illustrated in fig. 2, the reference void 3 and the sample void 2 may be arranged side-by-side or one void above the other in the sampling pipette and cuvette (not illustrated).

The sample as well as the reference void 2, 3 may have a cylindrical shape in an un-compressed state that is what is disclosed in fig. 1 and 2, right hand side, upper part. The cylindrical shape is provided with rounded ends as also illustrated in the figures. The rounded end is typically provided to ease production of the SPAC and/or to avoid notch effects upon compression of the void, as e.g. a cylindrical shape with plane top and bottom may have a tendency to produce buckling at the position of the optical windows 13. The size of the voids 2, 3 and in particular the dimension of the sample void 2 may be selected to provide a volume of sample being sufficient to provide a representative sample of the fluid to be measured. Examples on dimensions are diameter smaller than 30 mm and a length smaller than 300mm such as a diameter smaller than 4 mm and a length smaller than 30 mm.

The SPAC may be configured to suck into the sample void a fluid sample. In such embodiments, the SPAC comprising a suction element 6 adapted to suck fluid through the tubular channel 4 and into the sample void 2. Such a suction element 6 is typically an element being configured to provide a pressure inside the sample void 2 being smaller than the pressure in the surroundings of the SPAC and of a size being sufficient to suck fluid through the tubular channel 4 and into the sample void 2.

In the specific embodiment shown in fig. 2, the suction element 6 comprises a resilient and compressible section of the SPAC forming a suction void 7 in fluid communication with the sample void 2 via a suction channel 9. The suction element of the cuvette 1 is made so as to be compressible by hand (or by a tool) so that upon compression the volume of the suction void 7 is reduced and upon release of the compression the suction void 7 resiliently revert to its uncompressible form. This results in a pumping action propagated to the inlet 5 of the tubular channel 4 which sucks fluid into the sample void 2 when the inlet 5 is placed in a fluid.

The volume of the sample introduced into the sample void 2 may be controlled by the size of the suction void 7 since the volume sucked depends inter alia on the size of the suction void 7 being compressed. In the preferred embodiment shown in fig. 1 and 2, the suction void 7 has a smaller volume than the sample void 2, so as to provide a head space 10 above a sample being sucked into the sample void 2.

It is noted that a repetition of the pumping action by compressing the suction void 7 may be carried out whereby a gradually filling of sample into the sample void 2 can be provided, inter alia as the tubular channel outlet is arranged at a distance from the bottom of the sample void 2. This requires that the volume of the suction void 7 is larger than the volume of the tubular channel 4.

In embodiments wherein the SPAC comprising a reference void 3, this reference void can contain a specific fluid, e.g. to provide a well-defined reference absorbance when the SPAC is applied in measurement. Thus, the reference void 3 may contain a reference fluid, such as water or air (or other suitable reference fluid), or the reference void (3) may be evacuated, that is substantially not containing any fluid. In the embodiments where the reference void 3 is a confined void, the reference fluid is typically introduced into the reference void 3 during production of the SPAC and similarly if the reference void is evacuated, this is also preferably provided during production. If the reference void 3 is not confined, it has a fluid communication opening allowing introduction of reference fluid or evacuation.

One advantage of the present invention is that it may be produced from relatively inexpensive materials and by a relatively simple production method, such as e.g. a bottle moulding process. For example, a sampling pipette and cuvette 1 can be made from a single material, such as a single material composition, being selected from the group consisting of polymeric plastic material, such as PTFE, PELD, PEHD, PFA. It may be necessary to produce the SPAC in an environment cleaned from impurities to avoid impurities to be introduced into void(s) of the SPAC. Further, if for instance injection moulding is used, the surface(s) of the mould forming the section which are to be used as optical windows, these surface should preferably be given a smoothness preventing moulding marks which could otherwise jeopardise the transmission of the optical windows.

While it is within the scope of the present invention that the SPAC is made from a single material (as outlined above), the SPAC can also be made from multiple materials (in sense of different materials). This is typically applied in embodiments, wherein the optical windows 13 are made from one material, such as PFA or PFTE, and the remaining part of the sampling pipette and cuvette 1 is made from a plastic material, such as PE-LD, PE-HD. This may be provided by bonding e.g by use of cyanoacrylate PFTE to PELH or PEHD; in a process, the SPAC may be moulded to have openings mating the optical windows 13 which subsequently a bonded to SPAC in the openings.

To fulfil the various desires as to transmission and compressibility, the SPAC is preferably manufactured with wall section(s) 8 forming the sample void 2 has a substantial uniform thickness, where substantial uniform refers to the accuracy obtainable in production. The wall thickness is typically selected to be less than 1mm, such as less than 0.5 mm.

Similarly, the wall section(s) 8 forming the reference void 3 has a substantial uniform thickness, said wall thickness being less than 1 mm such as less than 0.5 mm.

The size of the sample void 2 and when present, the reference void is selected according to the purpose for use. In some cases, a representative sample is to be measured and in such situations, the volume needed to provide a representative sample can be determined. Within the scope of the invention is considered to be SPACs with a volume of the sample void 2 and a volume of the reference void 7, being smaller than 400ml, such as smaller than 300 ml, such as smaller than 200 ml, preferably smaller 150 ml, such as smaller than 100 ml, preferably smaller than 50ml, such as smaller than 25 ml, preferably smaller than 15 ml, preferably smaller than 10 ml, such as smaller than 5ml.

Due to its design, the SPAC is considered to be a single-time-use cuvette. This feature is provided inter alia by the relatively inexpensive production of the SPAC and that the SPAC typically is impractical to clean.

The invention also relates to a method of carrying out spectroscopy, such as an absorbance spectrum, on a fluid sample, preferably being a liquid sample. Such method utilises an SPAC as disclosed herein.

Reference is made to fig. 4. The method of carrying out spectroscopy by use of the SPAC, and the method typically commences by arranging a fluid sample in the sample void 2. With reference to the embodiments shown in fig. 1 and 2, this is carried by a user compresses the suction element 6 and introduces the end of the tubular channel 4 comprising the inlet 5 in the fluid to be measured where after the compression of the suction element 6 is released and the resiliency of the suction element 6 will make the suction reverting to its uncompressed state thereby sucking up a sample fluid into the sample void 2.

Once the sample is contained in the sample void, the method preferably involves the step of compressing the wall section(s) 8 of the sample void 2 so as to define two opposite substantial parallel wall sections 12 including the optical windows 13 spaced apart with predetermined distance d to provide a preselected linear optical path length through the sample between the said two adjacent substantial parallel wall sections 12. This is schematically illustrated in fig. 3. By compressing to have a predetermined distance, the optical path through the sample is determined and thereby also the distance the lights passed through a sample.

The method also includes the step of radiating light through the sampling sample void 2 along the linear optical path length and record a spectrum for the sample (SS).

Depending on the type of measurement to be carried, difference approaches can be selected and in some preferred embodiments, the further comprising determining a reference spectrum (RS). Such a reference spectrum is used to weight the spectrum of the sample (SS) on the basis of the reference spectrum (RS) to obtain an absorbance spectrum for the sample (ASS) or alternatively a transmission spectrum (TSS).

While a reference spectrum may be defined in a number of ways, the present invention may preferably use a reference spectrum determined on the basis of a measurement in the SPAC corresponding to a measurement where no sample is present in the sample void.

In some preferred embodiments, the reference spectrum (RAS) is provided by introducing an amount of the sample into the sample void 2 at an amount providing a head space 10 (see fig. 1) in the sample void 2 above the sample, and record the spectrum for light passing through the head space 10 and assign this spectrum to be the reference spectrum (RS). It is noted that the optical window extend both the section comprising the sample and the head space 10.

In other embodiment, the SPAC comprises a reference void 3 (see fig. 2) and in such embodiments, the reference spectrum may be obtained by passing light through the reference void 3. It is noted that it is preferred that the optical windows or the transparency of the sample void 2 and the reference void 3 are similar such as substantial identical to eliminate errors in the measurement arising from difference (and unknown) transmissivities.

When a reference void 3 is present, the reference spectrum (RS) is typically provided by compressing the wall section(s) 8 of the reference void 3 so as to define two opposite substantial parallel wall sections 12 spaced apart with predetermined distance d to provide a preselected linear optical path length (preferably being predetermined, but variable to meet requirement of different product types to be sampled) through the sample cuvette through and between the said two adjacent substantial parallel wall sections. As for the sample void, the distance d typically varies with different sample compositions. However, the distance d is typically equal for both the sample void 2 and the reference void 3.

Once the reference void is compressed light is radiated through the reference void 3 along the linear optical path length and the spectrum is recorded and assigned to be the reference spectrum (RS).

For some samples, the transmission and thereby the obtained spectrum can be influenced by the temperature of the sample. To eliminate this or in general to control the measurement, the method may comprising controlling, prior to and/or during recording of the spectrum, the temperature of the sample to a preselected temperature or to be within a preselected temperature range. Such a controlling may be provided by heating and/or cooling the sample, e.g. by Peltier elements or other suitable temperature controlling device, and the heating and/or cooling aims at in certain embodiments, to control the temperature to be below 100°C, such as below 50°C, preferably below 30°C and above 0°C. In a preferred embodiment, the temperature is selected to be substantially 40°C where substantially refers to the accuracy obtainable.

The SPAC typically has dimension being larger than the light beam used to obtain the spectrum and in such cases the radiation of light provides a light beam having a cross section being smaller than the size of the optical windows 13, and the method provides a scan of the sample in the sample void 2 by a scanning movement of the light beam relatively to optical windows 13, thereby obtaining a spatial scan of the sample.

The scanning movement can be provided by a relatively and translatory movement of the SPAC, in the sense that both the light source and/or the SPAC can be moved relatively to each other.

The method may further comprises the step of determining a samples heterogeneity by analysing the spatial scan of the sample to identify spatial variations, e.g. by determining the standard variation in the spatial scan.

A method according to any of the claims 20-27, further comprising determining measurement repeatability by providing a number, such as two, three or more spectra and analysing variations, such as the dispersion, between the spectra, the spectra may be at the same spatial position or spatial scans.

In a further aspect, the invention relates to a method of carrying out spectroscopy, preferably as presented otherwise herein, at a preselected temperature, being the temperature at which the spectroscopy is selected to be carried out. This may in certain preferred embodiment be 40°C e.g. when that sample is a milk sample.

Often, the sample has a temperature being different, such as higher or lower than the preselected temperature and if for instance the apparatus as disclosed herein, the compressing elements 29 (see fig. 4) may be used to heat or cool the sample. However, the time needed to set the temperature of the sample varies depending on inter alia the initial temperature of the sample. Thus, one may set a waiting time to be sufficient long to guarantee that the sample has reached (through heat conduction) the preselected temperature, and even in such situation, it may not be a guarantee that the whole body of the sample has reach the preselected temperature, and in any event, the waiting time may at least potentially slow down the spectroscopy measurement.

Instead of introducing a waiting time or even introducing thermos sensors to measure the temperature of the sample, the present invention applies in some preferred embodiment, a principle in which the temperature of the sample is determined from the a spectrum obtained from the sample.

This principle is based on that in water, hydrogen of one water molecule has 2, 3 or 4 bonds to oxygen of other water molecules where the number of bonds decreases as the temperature increases. As a rule of thumb, approximately 40% of the water molecules has 4 bonds at room temperature. Water absorbs light at 1400 nm (nanometer), although this in a spectrum is visible as a relatively wide peak composed of peaks from 2, 3 and 4 bonds, all being different. As temperature increases, the peak is slightly shifted and is has been found that this shift is highly visible and can be used to determine the temperature of the water and if the sample contains water, it is considered that thermo-equilibrium has established. At a wavelength of 1443 nm (nanometer) for water, this phenomenon has been found to be highly expressed.

To apply this principle, a method according to the present invention may comprise the consecutive steps of:

i) identifying from the spectrum whether the sample has a preselected temperature, preferably within a preselected span of temperature, such as within +-0.5°C of the preselected temperature, preferably within +-0.1°C of the preselected temperature, and ii) if the temperature has a temperature deviating from the preselected temperature, then cooling or heating the sample and repeat step i);

iii) if the sample has the preselected temperature, preferably within a preselected span of temperature, such as within +-0.5°C of the preselected temperature, preferably within +-0.1°C of the preselected temperature, the spectrum obtained is considered to the spectrum for the sample obtained at the preselected temperature.

The cooling in step ii) may either be an active cooling or heating in which e.g. Peltier elements are used to provide the cooling or heating or it may be a control of the temperature of the surroundings in general. It is noted that although this method is disclosed in connection with the SPAC, the apparatus and method disclosed herein, the scope of the method of determining the temperature based on spectrum is not to be limited thereto.

Reference is made to fig. 3 schematically illustrating a device for presenting a sample to a spectrometer. As illustrated the device has a holder 24 configured for receiving and holding an SPAC 1. The holder is in fig. 3 illustrated as comprising two adjacent compressing elements 29 being horizontally displaceable so as to vary the distance in between the two compressing elements 29. In fig. 3, the two compressing elements 29 are shown with an SPAC 1 in between them and in a configuration where they compress the sample void 2 to have a predetermined distance d inside.

Thus, the compressing elements 29 being configured for compressing wall sections 8 of the SPAC 1 to provide two adjacent substantial parallel wall sections spaced apart with predetermined distance d to provide a predetermined linear optical path length through the sample cuvette through and between the said two adjacent substantial parallel wall sections. This may be provided by the two adjacent compressing elements 29 each has plane surface being parallel to the adjacent one of the plane surface.

The device also comprising transmitting optics 22 arranged to radiate light along the linear optical path length and receiving optics 26 arranged to receive the light transmitted by the transmitting optics 22.

The device may further comprising means for controlling, prior to and/or during recording the spectrum, the temperature of the sample to a preselected temperature or to be within a preselected temperature range. Such means may be in the form of heating and/or cooling elements, such as Peltier elements. The means are configured to heat and/or cool the sample so the that its temperature is selected to be below 100°C, such as below 50°C, preferably below 30°C and above 0°C. The temperature of the sample, may be determined by a sensor sensing the temperature of the sample e.g. by sensing the temperature of the wall of the sample void. Alternatively, the temperature may be set by assuming a thermal equilibrium has been established between the sample and the heating and/or cooling element after some time.

List of itemized embodiments and aspects of the invention In following list, further embodiments and aspect are presented.

Item 1. A sampling pipette and cuvette (1) comprising:

a sample void (2) formed in the sampling pipette and cuvette (1); the sample void (2) being formed by a wall section(s) (8) of the cuvette (1) where said wall section(s) (8) defines an outer surface of said cuvette; a tubular channel (4) extending from an inlet (5) arranged at distal end of the sampling pipette and cuvette to the sample void (2);

the wall section (8) being made from an elastic material allowing deformation of the sample void (2) and the wall section(s) (8) comprising two optical windows (13) being translucent to light with a wavelength in the range of UV,VIS and/or NIR with a transmission of at least 50%, said optical windows (13) being opposite to each other, so as to allow light to be emitted through the sample void (2) by passing through the optical windows (13).

Item 2. A sampling pipette and cuvette (1) according to item 1, further comprising a reference void (3) not being in fluid communication with the sample void (2), the reference void (3) being formed by a wall section(s) (8) of the cuvette (1) where said wall section(s) (8) being made from an elastic material allowing deformation of the reference void (2) and the wall sections (8) comprising two optical windows (13) being translucent to light with a wavelength in the range of UV,VIS and/or-NIR with a transmission of at least 50%, said optical windows (13) being arranged opposite to each other, so as to allow light to be emitted through the reference void (2) by passing through the optical windows (13).

Item 3. A sampling pipette and cuvette (1) according to item 2, wherein the reference void (3) is a confined void.

Item 4. A sampling pipette and cuvette (1) according to item 2 or 3, wherein the sample void (2) and the reference void (3) are substantially geometrically identical to each other and being arranged side-by-side or in one void above the other in the sampling pipette and cuvette (1).

Item 5. A sampling pipette and cuvette (1) according to any of the preceding items, wherein the sample void (2) and, when dependant on items 2-4 the reference void (3) have a cylindrical shape in an un-compressed state, preferably both with a diameter smaller than 30 mm and a length smaller than 300mm such as a diameter smaller than 4 mm and a length smaller than 30 mm.

Item 6. A sampling pipette and cuvette (1) according to any of the preceding items, further comprising a suction element (6) adapted to suck fluid through the tubular channel (4) and into the sample void (2).

Item 7. A sampling pipette and cuvette (1) according to item 6, wherein the suction element (6) comprising a resilient and compressible section of the cuvette (1) forming a suction void (7) in fluid communication with the sample void (2), wherein the suction element of the cuvette (1) is compressible by hand or by a tool so that upon compression the volume of the suction void (7) is reduced and upon release of the compression the suction void (7) resiliently revert to its uncompressible form.

Item 8. A sampling pipette and cuvette (1) according to item 7, wherein the suction void (7) is in fluid communication with the sample void (2) via a suction channel (9).

Item 9. A sampling pipette and cuvette (1) according to item 7 or 8, wherein the suction void (7) has a smaller volume than the sample void (2), so as to provide a head space (10) above a sample being sucked into the sample void (2).

Item 10. A sampling pipette and cuvette (1) according to any of the preceding items, wherein the reference void (3) contains a reference fluid, such as water or air, or wherein the reference void (3) is evacuated.

Item 11. A sampling pipette and cuvette (1) according to any of the preceding items, wherein the sampling pipette and cuvette (1) is made from a single material, such as a single material composition, being selected from the group consisting of polymeric plastic material, such as PTFE, PELD, PEHD, PFA.

Item 12. A sampling pipette and cuvette (1) according to any of the preceding items 10, wherein the sampling pipette and cuvette (1) is made from multiple materials, wherein the optical windows (13) are made from one material, such as PFA or PFTE, and the remaining part of the sampling pipette and cuvette (1) is made from a plastic material, such as PELD, PEHD.

Item 13. A sampling pipette and cuvette (1) according to any of the preceding items, wherein wall section(s) (8) forming the sample void has a substantial uniform thickness, said wall thickness being less than 1mm, such as less than 0.5 mm.

Item 14. A sampling pipette and cuvette (1) according to any of the preceding items 2-13, wherein the wall section(s) (8) forming the reference void (3) has a substantial uniform thickness, said wall thickness being less than 1 mm such as less than 0.5 mm.

Item 15. A sampling pipette and cuvette (1) according to any of the preceding items, wherein the volume of the sample void (2) and when dependant on items 2-14, the reference void 7, is smaller than 400ml, such as smaller than 300 ml, such as smaller than 200 ml, preferably smaller 150 ml, such as smaller than 100 ml, preferably smaller than 50ml, such as smaller than 25 ml, preferably smaller than 15 ml, preferably smaller than 10 ml, such as smaller than 5ml.

Item 16. A sampling pipette and cuvette (1) according to any of the preceding items, wherein the sample cuvette is a single-time-use cuvette.

Item 17. A method of carrying out spectroscopy, such as an absorbance spectrum, on a fluid sample, preferably being a liquid sample, the method utilises a sampling pipette and cuvette (1) according to any of the preceding items, the method comprising arranging a fluid sample in the sample void (2);

compressing the wall section(s) (8) of the sample void (2) so as to define two opposite substantial parallel wall sections (12) including the optical windows (13) spaced apart with predetermined distance (d) to provide a preselected linear optical path length through the sample between the said two adjacent substantial parallel wall sections (12);

radiating light through the sampling sample void (2) along the linear optical path length and record an electromagnetic spectrum for the sample (SS) in the wavelength of UV,VIS and/or NIR.

Item 18. A method according to item 17, further comprising determining a reference spectrum (RS) and weighting the spectrum of the sample (SS) on the basis of the reference spectrum (RS) to obtain an absorbance spectrum for the sample (ASS) or alternatively a transmission spectrum (TSS).

Item 19. A method according to item 17 or 18, wherein the reference spectrum (RAS) is provided by introducing an amount of the sample into the sample void (2) at an amount providing a head space (10) in the sample void (2) above the sample, and record the spectrum for light passing through the head space (10) and assign this spectrum to be the reference spectrum (RS).

Item 20. A method according to any of items 17-19, wherein the method utilises a sampling pipette and cuvette (1) according to any of the preceding items 2-16, wherein the reference spectrum (RS) is provided by compressing the wall section(s) (8) of the reference void (3) so as to define two opposite substantial parallel wall sections (12) spaced apart with predetermined distance (d) to provide a preselected linear optical path length through the sample cuvette through and between the said two adjacent substantial parallel wall sections;

radiating light through the reference void (3) along the linear optical path length and record a spectrum assigned to be the reference spectrum (RS).

Item 21. A method according to any of items 17-20, further comprising controlling, prior to and/or during recording the spectrum, the temperature of the sample to a preselected temperature or to be within a preselected temperature range, the controlling being provided by heating and/or cooling the sample, wherein the temperature is selected to be below 100°C, such as below 50°C, preferably below 30°C and above 0°C, such as the temperature is selected to be substantially 40°C.

Item 22. A method according to any of the items 17-21, wherein the radiation of light provides a light beam having a cross section being smaller than the size of the optical windows (13), and wherein the method further comprising providing a scan of the sample in the sample void (2) by a scanning movement of the light beam relatively to optical windows (13), thereby obtaining a spatial scan of the sample.

Item 23. A method according to item 22, wherein the scanning movement being provided by a relatively and translatory movement of the sampling pipette and cuvette.

Item 24. A method according to any of the items 22-23, further comprising determining a samples heterogeneity by analysing the spatial scan of the sample to identify spatial variations.

Item 25. A method according to any of the items 17-24, further comprising determining measurement repeatability by providing a number, such as two, three or more spectra and analysing variations between the spectra.

Item 26. A method according to any of the preceding items 17-25, the method further comprising, the consecutive steps of:

Item 27. A device for presenting a sample to a spectrometer the device comprising:

a holder (24) configured for receiving and holding a sampling pipette and cuvette (1) according to any of the preceding items 1-16;

said holder (24) comprising compressing elements (29) being configured for compressing wall sections (8) of said cuvette (1) to provide two adjacent substantial parallel wall sections spaced apart with predetermined distance (d) to provide a predetermined linear optical path length through the sample cuvette through and between the said two adjacent substantial parallel wall sections;

transmitting optics (22) arranged to radiate light along the linear optical path length, and receiving optics (26) arranged to receive the light transmitted by the transmitting optics (22).

Item 28. A device according to item 27, the device further comprising means for controlling, prior to and/or during recording the spectrum, the temperature of the sample to a preselected temperature or to be within a preselected temperature range, the controlling being provided by heating and/or cooling the sample, wherein the temperature is selected to be below 100°C, such as below 50°C, preferably below 30°C and above 0°C.

Although the present invention has been described in connection with the specified embodiments, it should not be construed as being in any way limited to the presented examples. The scope of the present invention is set out by the accompanying claim set. In the context of the claims, the terms comprising or comprises do not exclude other possible elements or steps. Also, the mentioning of references such as a or an etc. should not be construed as excluding a plurality. The use of reference signs in the claims with respect to elements indicated in the figures shall also not be construed as limiting the scope of the invention. Furthermore, individual features mentioned in different claims, may possibly be advantageously combined, and the mentioning of these features in different claims does not exclude that a combination of features is not possible and advantageous.

List of reference symbols used:

Sampling pipette and cuvette

Sample void

Reference void

Tubular channel

Inlet

Suction element

Suction void

Wall section of cuvette

Suction channel

Head space

Sample substantial parallel wall sections

Optical window

Optical engine, Fourier transformation spectrometer, light module, power supply and control element;

Transmitting optics

Holder for sampling pipette and cuvette (including heating elements)

Receiving optics, receiving lights emitted through the transmitting optics, passing through the sampling pipette and cuvette compressing element i

Claims

Patent claims

A sampling pipette and cuvette (1) comprising:

a sample cavity (2) formed in the sampling pipette and cuvette (1); wherein the sample cavity (2) is formed by one / more wall sections (8) of the cuvette (1), said wall section (8) defining an outer surface of said cuvette; a tubular channel (4) extending from an inlet (5) located at the distal end of the sampling pipette and cuvette to the sample cavity (2); wherein the wall section (s) (8) comprises two optical windows (13) which are translucent to light having a wavelength in the range of UV, VIS and / or NIR with a transmission of at least 50%, said optical windows (13) being opposite to each other, so as to allow light to be emitted through the sample cavity (2) by passing through the optical windows (13), characterized in that the wall section (8) is made of an elastic material which allows deformation of the sample cavity ( 2).

The sampling pipette and cuvette (1) according to claim 1, characterized in that further comprises a reference cavity (3) which is not in fluid communication with the sample cavity (2), the reference cavity (3) being formed by one / more wall sections (8). ) of the cuvette (1), said wall section (8) being made of an elastic material which allows deformation of the reference cavity (2), and wherein the wall sections (8) comprise two optical windows (13) which are translucent to light with a wavelength in the range of UV, VIS and / or NIR with a transmission of at least 50%, said optical windows (13) being placed opposite each other, so as to allow light to be emitted through the reference cavity (2) by passing through the optical windows (13).

Sampling pipette and cuvette (1) according to claim 2, characterized in that the sample cavity (2) and the reference cavity (3) are substantially geometrically identical to each other and are arranged side-by-side or a cavity above each other in the sampling pipette and cuvettes (1).

Sampling pipette and cuvette (1) according to any one of the preceding claims, characterized in that further comprises a suction element (6) arranged to suck fluid through the tubular channel (4) and into the sample cavity (2).

Sampling pipette and cuvette (1) according to claim 4, characterized in that the suction element (6) comprises an elastic and compressible section of the cuvette (1) which forms a suction cavity (7) in fluid communication with the sample cavity (2), wherein the suction element of the cuvette (1) can be compressed by hand or with a tool so that upon compression the volume of the suction cavity (7) is reduced and upon release of the compression the suction cavity (7) returns elastically to its uncompressed shape.

Sampling pipette and cuvette (1) according to any one of the preceding claims, characterized in that the sampling pipette and cuvette (1) is made of a single material, such as a single material composition, selected from the group consisting of of polymeric plastic material such as PTFE, PELD, PEHD, PFA.

A method of performing a spectroscope, such as an absorbance spectrum, on a fluid sample, which is preferably a liquid sample, characterized in that the method uses a sampling pipette and cuvette (1) according to any one of the preceding claims, which method comprises :

placing a fluid sample in the sample cavity (2);

compressing the wall section (s) (8) of the sample cavity (2) so as to define two opposite substantially parallel wall sections (12) including the optical windows (13) spaced at predetermined distances (d) to provide a preselected linear optical path length through the sample between said two adjacent substantially parallel wall sections (12);

to radiate light through the sample cavity (2) along the linear optical path length and record an electromagnetic spectrum of the sample (SS) in the wavelengths of UV, VIS and / or NIR.

Method according to claim 7, characterized in that the reference spectrum (RAS) is provided by introducing an amount of the sample into the sample cavity (2) at an amount which provides a free volume (head space) (10) in the sample cavity (2) above the sample. , and record the spectrum of light passing through the free volume (10) and assign this spectrum to be the reference spectrum (RS).

A method according to claim 7 or 8, characterized in that the method uses a sampling pipette and cuvette (1) according to any one of the preceding claims 2-6, wherein the reference spectrum (RS) is provided by compressing the wall section (s) ( 8) of the reference cavity (3) so as to define two opposing substantially parallel parallel wall sections (12) spaced at predetermined distances (d) to provide a preselected linear optical path length through the sampling pipette and the cuvette through and between said two adjacent substantially parallel wall sections ;

radiating light through the reference cavity (3) along the linear optical path length and recording a spectrum assigned to be the reference spectrum (RS).

A method according to any one of claims 7-9, characterized in that the radiation of light provides a light beam with a cross section smaller than the size of the optical windows (13), and wherein the method further comprises:

to provide a scan of the sample in the sample cavity (2) by a scanning movement of the light beam relative to optical windows (13), thereby obtaining a spatial scan of the sample.

A method according to any one of the preceding claims 7-10, characterized in that the method further comprises the successive steps:

i) identifying from the spectrum whether the sample has a preselected temperature, preferably within a preselected range of temperature, such as within +0.5 ° C of the preselected temperature, preferably within + - 0.1 ° C of the preselected temperature , and ii) if the temperature has a temperature deviating from the preselected temperature, then to cool or heat the sample and repeat step i);

iii) if the sample has the preselected temperature, preferably within a preselected range of temperature, such as within + - 0.5 ° C of the preselected temperature, preferably within + - 0.1 ° C of the preselected temperature, the spectrum obtained considered as the spectrum of the sample obtained at the preselected temperature.

Device for presenting a sample to a Spectrometer, which device is characterized by comprising:

a holder (24) configured to receive and hold a sampling pipette and cuvette (1) according to any one of the preceding claims 1-6;

wherein said holder (24) comprises compression elements (29) which are

10 configured to compress wall sections (8) of said cuvette (1) to provide two adjacent substantially parallel wall sections spaced at predetermined distances (d) to provide a predetermined linear optical path length through the sampling pipette and the cuvette through and between said two adjacent significant parallel

15 wall sections;

transmitting optics (22) arranged to irradiate light along the linear optical path length, and receiving optics (26) arranged to receive the light transmitted by transmission optics (22).

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