DE202005019461U1 - Optical fluid flow-cell, e.g. for use in chromatography detection, comprises two main housing components and has a flow channel coated to provide total internal reflection - Google Patents

Abstract

Optical fluid flow-cell comprising a flow-cell housing (3) comprising two main components, one of which (1) has a surface carried fluid channel (19) and an optical path (21), where the first component (1) is sealed by a cover plate (25) clamped on by screws (27), or adhesively secured, where radiation is provided axially to the groove by an optical fibre or focussing system (29, 31) and fluid enters and leaves the channel via perpendicular bores (23), is new. An independent claim is also included for use of the cell in liquid and gas phase chromatography units, including apparatus for micro and nano scale determinations.

Description

STATE OF TECHNOLOGY

The The invention relates to a housing part for a flow cell.

flow cells are adapted to guide a fluid along a fluid path, wherein the guided Fluid for Can be used for analysis purposes. A flow cell can do one Have light path through the sample, ie through the fluid path through leads. The fluid or dissolved or dissolved sample weakens the electromagnetic radiation, such as light, from, wherein the Measure of mitigation conclusions allows the guided in the fluid path of the flow cell sample.

The US 6,526,188 B2 and US2001 / 0010747 show a modular flow cell having a high optical throughput, a long optical path length and a small cross section. The modular flow cell assembly includes supply connections or connections for liquid and light entry as well as liquid and light exit.

The US 5,444,807 shows a flow cell for use in measuring chemical properties of small volumes of fluid containing dissolved samples.

The US 5,608,517 shows a coated flow cell and a method of making such. The flow cell has a flow section wherein light directed into the flow cell is reflected internally along the flow section.

The US 3,236,602 shows a flow cell and corresponding holders therefor and the colorimetric examination of a liquid for determining the amount of a substance contained in the liquid.

The US 4,474,186 shows a photometric cuvette for optical analysis of a flowing medium, wherein the cuvette is made as a thin and narrow transparent tube, which requires only a minimum amount of sample. Light that is substantially parallel to the length of the tube is directed obliquely into the tube, through the wall of the tube, is reflected, and is directed obliquely through the wall of the tube to a detector.

The EP 008915781 shows an optical detection cell for detecting a solute in a sample fluid. The optical detection cell includes a sample tube, means for introducing and discharging the sample fluid, and first and second optical fibers for axially passing a light beam through the sample tube.

The GB 2193313A shows an apparatus and method for measuring the spectral absorbance of fluid samples. The length of the light path through the sample is adjusted to optimize the amount of light absorbed by the sample.

The US 6,281,975 B1 Fig. 10 shows a bent capillary flow cell with protruding end pistons coaxial with the centerline of an elongated cylindrical central region of the capillary tube. The pistons allow for a high light throughput suitable input window for the cell.

EPIPHANY

task The invention is an improved flow cell and improved Components for to provide a flow cell.

The The object is solved by the independent claims. Further advantageous embodiments arise from the rest Dependent claims.

Corresponding embodiments The invention is a housing part for one Flow cell having a fluid path for guiding a fluid and a Suggested light path. Advantageously, the fluid can flow along a groove of the housing part are guided, wherein the groove is a portion of the fluid path of the housing part or the flow cell provides. The groove can do a first Section, which is part of the fluid path. At least the first one Section of the groove has a modification, that is with a Material coated, modified and / or such that at least at the interface the optical density is lower is, as that of leading in it Fluid. This has the consequence that at the interface between the fluid and the coating and / or the boundary material total reflection occur can. A modification of the boundary layer can, for example, by In particular, glass can be doped with fluorine.

The Total reflection possible it is that rays of light that are coated in the first section of the Groove be fed inside the groove, provided they are in one sufficiently small angle - from Inside the fluid path seen from - impinge on the coating. The angle must be smaller than the critical angle at which straight still total reflection occurs. This limit angle results the density difference of the coating material and the fluid, is thus in particular of the respective in the coated groove out Fluid, the wavelength as well as the optical properties of the coating.

at further embodiments is provided that the housing part is formed as a half shell, wherein two half shells to a casing the flow cell joined together can be. It is possible, form two half shells substantially symmetrical to each other. However, it is also possible only one housing part provided with the groove and this with a flat lid, the can also be coated to combine.

The two half shells of the housing the flow cell can be combined so that the flow cell has a first opening and a second opening has, in the optical elements, for example, a first optical waveguide and a second optical waveguide or even windows or lenses can be introduced. For this it is possible a first groove of the first half-shell and a second groove of the second half-shell each groove-shaped form, so that in the assembled state, two circular openings yield, in which the optical waveguide or lenses or windows can be introduced are.

In further embodiments it is provided that the coating comprises a polymer of the family of amorphous fluoropolymers, for example ^Teflon® AF. Such amorphous fluoropolymers have a relatively low refractive index, for example about 1.3 for visible light.

The Coating of the housing part or the corresponding portion of the groove of the housing part can be reduced by various methods, such as by spin coating, by spray coating, by dip coating, by Vapor deposition, by vacuum evaporation, CVD or similar methods. It is also possible to perform the coating in the form of a film. The foil can through increase the air pressure or by generating a vacuum or by pressing or by inserting into a corresponding injection molding tool the housing part be assigned. Depending on the selected Method, it is possible the entire housing part to coat.

Further it is conceivable, the groove stepped, for example as a stepped bore, perform, so that next to the first section results in a second section, wherein the waveguide are thus introduced into the second section that can be between the waveguide and the second section a circumferential gap results, so that the waveguide of a Fluid flows around can be. Furthermore may result in a third section, which serves as a receptacle for the optical waveguide in the form of a fit, for example a press fit can.

In further embodiments is provided that the housing part has at least one bore in the second section of Groove, ie in the Umströmbereich or the circumferential gap around the optical waveguide, opens. therefore Is it possible, the fluid path through the bore into the second section to guide the groove.

to Sealing of the fluid path, so for example in the bore as well as in the first portion and second portion of the groove guided fluid, Is it possible, to provide a sealing foil between the half-shells. The sealing foil can do this in a closed ring around the complete first Section and the second section of the groove, so that the ring is the first section of the groove in which the optical fiber can be brought in, crosses. Thus, by the sealing film of the entire Fluid leading Area within the composite shells, in particular towards the light pipe, sealed.

Corresponding further embodiments The inventions propose a flow cell, in particular two housing parts as described above.

Finally Embodiments of the Invention, which relate to a fluidic system, the has such a cell.

DESCRIPTION OF THE FIGURES

Other Tasks as well as many of the associated ones Advantages of embodiments The present invention will be readily understood with reference to the following detailed Description of exemplary embodiments and the accompanying drawing. Essentially the same, similar and / or functionally identical parts are provided with the same reference numerals.

1 shows a three-dimensional plan view of a housing part of a flow cell, wherein the housing part has a coated groove,

2 shows a three-dimensional plan view of a flow cell with two housing parts,

3 shows a plan view of a housing part of the flow cell 2 wherein the housing part has a coated groove,

4 shows a section of the top view 3 wherein a bore opening into the groove is visible,

5 shows a partially illustrated section of the in the 3 and 4 Ge shown Part of the flow cell, along the line VV in 4 .

6A and 6B each show a partially illustrated section of the in the 3 and 4 shown housing part of the flow cell in two different versions, along the line VI-VI in 4 , and

7 shows a schematic representation of a fluidic system with two flow cells.

1 shows a plan view of a housing part 1 a flow cell 3 , The housing part 1 the flow cell 3 has a groove 5 which is divided into three sections. The sections of the groove 5 are separated by steps from each other. From the middle of the groove 5 Seen from this, it goes from a first, deepest section 7 at a first stage 9 in a second section 11 above. The second section 11 goes to a second stage 13 into a flatter third section 15 above. It is conceivable to execute the sections equally deep, ie without the steps 9 and 13 ,

The groove 5 of the housing part 1 can, as in 1 shown from the middle of the housing part 1 seen to be mirror-symmetrical, so that the groove 5 two second sections 11 as well as two third sections 15 having. Hereinafter, reference to mirror-symmetric opposing parts in the singular, as appropriate, refers to both opposing parts unless explicitly indicated. At least one of the sections 7 . 11 . 15 the groove 5 has a coating 17 on, whose refractive index is relatively low. For example, this may be ^Teflon® AF. Advantageously, the coating 17 in the groove 5 a fluid path 19 and a light path 21 form. Advantageously, in the first section 7 the groove 5 the fluid path 19 and the light path 21 be merged. This can be a bore 23 in the second section 11 the groove 5 lead. The hole 23 , the second section 11 as well as the first section 7 are therefore parts of the fluid path 19 the flow cell 3 , That in the first section 7 the flow cell 3 guided fluid can by means of a in 1 not shown optical waveguide or other optical elements are irradiated. For this purpose, the optical fiber, not shown, in the first section 7 and the second section 11 be inserted so that at least the first section 7 can be irradiated. On the opposite side of the optical fiber, another, in 1 Also, not shown, optical fibers are arranged, the by the fluid in the first section 7 the groove 5 transmitted radiation can resume and optionally supply a measuring device, not shown.

2 shows a three-dimensional plan view with a first housing part 1 and a second housing part 25 , The housing parts 1 and 25 are formed as joinable half-shells. For connecting the housing parts 1 and 25 the flow cell 3 , show the housing parts 1 and 25 fittings 27 on. In place of the screw connections, any other type of connection, for example riveting, welding, clamping and / or the like may be provided. As in 2 shown, the flow cell 3 a first optical fiber 29 and a second optical fiber 31 on. It is possible the flow cell 3 , in particular the groove 5 the flow cell 3 in addition to or instead of optical fibers 29 and 31 to be provided with other optical elements, such as windows, lenses and / or the like.

3 shows a plan view of the first housing part 1 the flow cell 2 out 2 ,

The housing part 1 the flow cell 3 indicates the acceptance of the screw connections 27 drilling 33 on. You may be able to get more or less than four holes 33 be provided. The housing part 1 has a groove 5 on that in a first section 7 with an insert 35 is equipped. The insert 35 may, for example, have ^Teflon® AF. At the insert 35 it can be a slide. The insert 35 can in the groove 5 be pressed, for example by means of a suitable tool, by means of compressed air or by applying a vacuum.

In the embodiments, as in 3 shown, assign the sections 7 . 11 and 15 the groove 5 each have the same depth.

4 shows a detail of in 3 illustrated plan view of the first housing part 1 the flow cell 3 , It can be seen that the first optical fiber 29 in the groove 5 is inserted. Here is the first optical fiber 29 inserted so that an optical outlet 37 of the leader 29 in the first section 7 the groove 5 , with the insert 35 equipped, protrudes. This results in a slight overlap of the optical waveguide 29 with the insert 35 inside the groove 5 of the first housing part 1 , Advantageously, this can be done by additional sealing of the fluid path. The insert 35 So it can be in a sealing contact with the respective optical fiber 29 respectively 31 are located. It is also conceivable, as in 4 by a dashed line 38 indicated, the insert flush with the light waveguide 29 complete. The hole 23 flows into a section 7 the groove 5 and also penetrates the insert 35 ,

By means of the optical waveguide 29 can he first section 7 the groove 5 So in this section 7 guided fluid are irradiated. That along the light path 21 inside the groove 5 guided light can by means of the second optical waveguide 31 be received and supplied, for example, a detector, not shown for measurement and / or analysis purposes. As in the 3 and 4 shown, the flow cell 3 a seal 39 on, the rectangular at a distance around the insert 35 or the first section 7 the groove 5 the flow cell 3 revolves, or surrounds this / this rectangular. The seal 39 can be designed as a flat film in a second section 11 also in the groove 5 is inserted, so it can also seal. The seal 39 has at least one layer, in particular can be constructed in two layers, so a first layer 41 exhibit, as in the 3 and 4 is visible. The second housing part 25 can therefore one according to the first layer 41 the seal 39 mirror image opposite second layer 43 exhibit. The second layer 43 the seal 39 is in the 5 and 6 visible, noticeable.

The seal 39 may comprise a thermoplastic, thermosetting, elastomeric and / or metallic material, for example in the form of a structured one-part or multi-part body. Advantageously, the sealing effect can be achieved by mechanical deformation and / or heat treatment of the seal or assembly.

Further it is conceivable that the gasket is a solvent-resistant pre-seal, in particular having an elastomer, in combination with a high-pressure seal, in particular having an adhesive and designed for sealing high pressures, having. Advantageously, therefore, the high pressure seal by the pre-seal can be protected from highly aggressive solvents.

5 shows a partially illustrated section of the in the 3 and 4 shown first housing part 1 , along the line VV in 4 , Another partially illustrated section along the line VI-VI in 4 show the 6A and 6B ,

As 6B shows, it is possible the seal 39 in recesses 44 or depressions of the housing parts 1 and 25 accommodate. The recesses 44 the housing parts 1 and 25 may have a slightly smaller depth than the respective layer thickness of the associated layers 41 and 43 the seal 39 , The depth and the layer thickness can advantageously be used to set the maximum sealing force. Furthermore, the housing parts 1 and 25 be created flush with each other.

As in 5 recognizable, results in a sealing contact contact between an outer surface 45 of the first optical waveguide 29 and the respective adjacent layer 41 . 43 the seal 39 , The layers 41 and 43 are so in the grooves 5 the housing parts 1 and 25 inserted, that this also in a sealing contact contact of the surface 45 of the first optical waveguide 29 and the surface of the grooves 5 stand. Outside the grooves 5 the housing parts 1 and 25 stand the layers 41 and 43 in a sealing contact with the surfaces 49 the housing parts 1 and 25 the flow cell 3 , due to the closed annular design of the layers 41 and 43 the seal 39 a possible fluid exit from the fluid path 19 the flow cell 3 can be avoided.

The sealing forces required for this purpose, for example, by mechanical distortion of the housing parts 1 and 25 the flow cell 3 , for example by means of the fittings 27 to be applied. For making the seal 39 is it possible the layers 41 and 43 the seal 39 during assembly of the flow cell 3 insert accordingly. However, it is also possible, the housing parts 1 and 25 directly with the seal 39 to coat, for example by brushing, spray coating, vapor deposition, CVD (Chemical Vapor Deposition) or the like.

Furthermore, it is conceivable, instead of or in addition to the mechanically applied sealing forces, to produce a sealing connection by means of a heat treatment, for example by hot gluing. It can be the seal 39 even have a heat-adhesive material or consist of this. It is possible, the seal 39 together with the housing parts 1 and 25 the flow cell 3 to heat. The seal 39 may include materials such as FEP, PFA or PEEK. Advantageously, for example, when using FEP, the entire assembly can be heated to a temperature of about 250 - 280 °, which is still below the melting point of the addition - in particular for the fluid path 19 - Used material Teflon ^® AF of about 360 °. As a result, it is ensured that the heat treatment for the light-guiding properties of the groove 5 necessary coating is not destroyed. Furthermore, it is conceivable, the housing parts 1 and 25 the flow cell 3 from a transparent material, for example to manufacture glass. In this case, the seal 39 melted by laser welding and accordingly with itself and with the housing parts 1 and 25 be connected, so that there is the sealing contact between the components to be sealed.

Finally, it is conceivable components to Ab densities of the fluid path 19 provide, for example, this before mounting the housing parts 1 and 25 appeal. These can then be welded and / or pressed by one of the methods described above.

As in 5 recognizable, the hole can 23 acting as fluid supply or fluid removal of the fluid path 19 serves as a stepped bore with a step 47 be executed. The - in alignment of 5 seen - below lying portion of the hole 23 which has a larger diameter may be provided, for example, with a thread, not shown. By means of the thread, not shown, for example, a compound, preferably a standard connection in the bore 23 be screwed.

7 shows a fluidic system 201 with a fluid source 203 and a fluid sink 205 , Between the fluid source 203 and the fluid sink 205 indicates the fluidic system 201 a fluid path 207 on. The fluid path 207 is with a light path 209 coupled. Preferably, the fluid path 207 also with another light path 211 be coupled. The fluid path 207 as well as the first and second light path 209 and 211 are parts of a first and second flow cell 213 and 215 , For coupling the fluid path 207 and the light path 209 or for the realization of the first and second flow cell 211 such as 213 indicates the fluidic system 201 at least one coupling device 217 on. Each of the flow cells 213 and 215 each has a housing part 219 with a groove 221 and a coating 223 , as well as at least one optical fiber 225 on. The groove 221 is designed to guide a sample, in particular a sample dissolved in a liquid.

The fluid source 203 can a not shown separating device 227 and / or be coupled with this. Furthermore, each of the light paths 209 . 211 be connected to a detector.

Furthermore, the fluid sink 205 an analysis device 229 , eg, a mass spectrograph (MS), be assigned or have such.

Claims (24)

Housing part for a flow cell ( 3 ) with a fluid path ( 19 ) for guiding a fluid and a light path ( 21 ) for guiding light, - wherein the housing part ( 1 ) a groove ( 5 ) for guiding the fluid path ( 19 ), wherein at least a first section ( 7 ) of the groove ( 5 ) has a modification whose optical density is lower than that of the fluid, so that total reflection can occur at the interface to the modification. Housing part according to one of the preceding claims, wherein the modification as a coating ( 17 ) and / or as surface modification, in particular doping. Housing part according to one of the preceding claims, wherein the housing part ( 1 ) with a second housing part ( 25 ) is joinable. Housing part according to one of the preceding claims, wherein the coating ( 17 ) Teflon ^® AF. Housing part according to one of the preceding claims, wherein the coating ( 17 ) by painting, spin coating, spray coating, vapor deposition and / or dip coating can be applied. Housing part according to one of the preceding claims, wherein beside the first section ( 7 ) of the groove ( 5 ) further parts of the housing part ( 1 ), in particular the entire housing part ( 1 ), with the coating ( 17 ) are provided. Housing part according to one of the preceding claims, wherein the first section ( 7 ) of the groove ( 5 ) for guiding the fluid path ( 19 ) and the light path ( 21 ) is designed. Housing part according to one of the preceding claims, wherein the groove ( 5 ) is designed to receive an optical element. Housing part according to the preceding claim, wherein the optical element as a lens, window, and / or optical waveguide ( 29 ) 31 ) is designed. Housing part according to one of the preceding claims, wherein the groove ( 5 ) a second section ( 11 ) designed to receive the fluid path ( 19 ) and the optical element, in particular the optical waveguide ( 29 ) 31 ), and a third section ( 15 ), designed to receive the optical element, in particular the optical waveguide ( 29 ) 31 ), having. Housing part according to one of the preceding claims, wherein the housing part ( 1 ) a seal ( 39 ), in particular a seal with at least one layer, designed for fluid-tight sealing of the fluid path (US Pat. 19 ) having. Housing part according to the preceding claim, wherein the seal ( 39 ) a first layer ( 41 ) as well as a second layer ( 43 ), which lie on one another in regions and in regions on a surface ( 45 ) of the optical waveguide ( 29 . 31 ) or against a surface of the optical elements Housing part according to one of the preceding claims, wherein the seal ( 39 ) has a thermoplastic, thermosetting, elastomeric and / or metallic material. housing part according to any one of the preceding claims, wherein the seal is a solvent resistant pre-seal, in particular having an elastomer, in combination with a High pressure seal, in particular having an adhesive and designed for sealing at high pressures, having. Housing part according to one of the preceding claims, wherein the fluid path ( 19 ) of the first housing part ( 1 ) at least one bore ( 23 ) designed to carry a fluid. Housing part according to one of the preceding claims, wherein the coating ( 17 ) as an insert ( 35 ) in the groove ( 5 ) is executed. Housing part according to one of the preceding claims, wherein the optical waveguides ( 29 . 31 ) and / or the optical elements in the third section ( 15 ) of the groove ( 5 ) are inserted. Housing part according to one of the preceding claims, wherein the fluid path ( 19 ) is designed for guiding a fluid. Housing part according to one of the preceding claims, wherein the groove ( 5 ) of the first housing part ( 1 ) is adapted to a first optical waveguide ( 29 ) and a second optical fiber ( 31 ) and / or the optical elements. Flow cell designed to guide and expose a fluid for analysis purposes, with a housing part according to one of the preceding claims. Flow cell according to the preceding claim, with a first housing part ( 1 ), wherein the first housing part ( 1 ) a groove ( 5 ) and a coating ( 17 ) having. A flow cell according to the preceding claim, wherein the flow cell has two of the housing parts. Fluidic system with a flow cell ( 213 . 215 ) according to one of the preceding three claims, comprising: - a fluid source ( 203 ), - a separating device ( 223 ) adapted to separate components of the fluid sample passing through the fluid source ( 203 ), and - the flow cell ( 213 ; 215 ), in particular two coupled flow cells ( 213 ) and ( 215 ) designed to detect the separated components of the fluid sample. Fluidic system according to one of the preceding four claims, wherein the fluidic system ( 201 ) comprises at least one of the following devices: - a liquid chromatograph (LC), - a high performance liquid chromatography (HPLC) system, - a single-chip HPLC and mass spectrograph (MS), - a high throughput LC / MS System, - a treatment, purification, and / or refining system, - a micro fraction collection / spotting system, - a system designed to identify proteins, - a system with a GPC / SEC column, - a nanofluid LC system , - a multidimensional LC system designed to separate dissolved and chemically digested proteins.