WO1989004473A1

WO1989004473A1 - A measuring system for use in continuous flow analysis of liquids

Info

Publication number: WO1989004473A1
Application number: PCT/DK1988/000180
Authority: WO
Inventors: Kim JØRGENSEN; Jan Nørager RASMUSSEN; Peter Haagensen
Original assignee: Carlsberg Forskningscenter
Priority date: 1987-11-04
Filing date: 1988-11-03
Publication date: 1989-05-18
Also published as: DK578587D0; DK578587A; AU2724888A; DK157326C; DK157326B

Abstract

A measuring system for use in continuous flow analysis consists of a plurality of standardized blocks (10) containing a metering valve (11), a channel system and a flow cuvette (21) as well as a common detector housing (24) adapted to receive each of these blocks, said detector housing (24) having means for measuring the concentration in the cuvette of sample liquid in a reagent liquid. As an indication of this may be used either the subduing of light emitted through the cuvette, or the intensity of fluorescent light emitted by the cuvette liquid when it is illuminated by light with a suitable wavelength.

Description

A measuring system for use in continuous flow analysis of liquids

The invention concerns a measuring system of the type defined in the introductory portion of claim 1. Such a measuring system with integrated blocks for performance of various forms of continuous flow analysis is shown and described in the Danish Patent Application 4296/82. The firm structure and physical stability of the block provide good conditions of obtaining reliable analysis results.

The object of the invention is to rationalize the use of the present system, and this object is achieved in that the system is constructed as stated in the characterizing portion of claim 1 since performance of a specific, desired analysis then just requires selection of the block adapted for this analysis, mounting of the block in the detector housing and connection of a few liquid lines.

Expedient details of the measuring system are stated in claims 2-4, and claim 5 defines a particularly advantageous embodiment where the physical properties of the block are utilized for incorporating a metering valve known per se, which is capable of metering very small amounts of liquid with great precision.

The invention will be explained more fully below with reference to the drawing, in which

fig. 1 is a perspective view of an analysis block for use in the measuring system of the invention,

fig. 2 is a lateral and partially sectional view of the block mounted in a detector housing, fig. 3 shows the same in top and partially sectional vie , and

fig. 4 is a lateral and partially sectional view of an amended embodiment of a block mounted in the detector housing.

The substantially box-shaped block 10 shown in fig. 1 consists of a suitable plastics material* such as e.g. polyvinyl chloride or vinyl acetate. At one end the block has a through bore which extends from one side edge fac¬ to the other, and in which a cylindrical metering valve body 11 known per se is slidable axially as indicated b arrows 12 and 13 between two positions, e.g. hydraulicaJ - ly, magnetically or pneumatically. The valve body 11 is formed with three annular grooves 14, 15 and 16 with mutual distances corresponding to the distances between the two valve positions and with volumes corresponding to the desired metered amount. In the position shown, the central groove 15 is present opposite an inlet channel 17 for the sample liquid to be supplied in a carefully metered amount, as well as opposite an outlet channel 18 for this liquid. The two channels 17 and 18 are disposed at diametrically opposite points of the groove 15. In this valve position the groove 15 will thus be filled with liquid which flows in through the channel 17 and out through the channel 18. If the valve body is then moved to the right, i.e. in the direction of the arrow 12, the groove 15 will be disposed between a supply channel 19 for a reagent liquid and one end of a channel system 20, which is provided in the underside of the block 10 and covered by a plate glued on to it. The groove 14 is in¬ serted into the sample liquid circuit at the same time so that this circuit is interrupted only for the very short time it takes for the valve to change its position. The other end of the channel system 20 is connected with a glass cuvette 21 extending through a recess 22 in the end of the block 10 which is disposed opposite the meter¬ ing valve. The liquid flows from the cuvette 21 out through a discharge channel 23.

Figs. 2 and 3 show the block 10 mounted in a box-shaped detector housing 24 which defines an upwardly open space 25 having dimensions adapted to receive the block. At one end of the housing there is provided a relatively low recess on the underside, the bottom of said recess being covered by a exchangeable excitation filter 27. From this bottom extend partly a slot 28 through which the cuvette 21 of the block can be illuminated from a source of light 29 through the filter 27, partly a chamber 30 in which a measuring means (not shown), e.g. a photodiode may be placed for measuring the light intensity from the light source 29. In the present case, the liquid sample is of a type such that it is caused to fluoresce by the light filtrated by the filter 29 and thus emit light of another frequency.

This light passes through an exchangeable emission filter 30 to a light detector (not shown), which is placed in a recess 31 at the end of the housing 24. The detector applies a signal which is indicative of the concentration of sample liquid in the reagent liquid in the cuvette.

Fig. 4 shows another embodiment of an analysis block, here designated 40, placed in the detector housing 24. This block differs from the block 10 in having the cuvette, here designated 41, disposed at right angles to the end face of the block and in having a built-in source of light in the form of a light diode 42 disposed at the inner end of the cuvette and separated from it by a window 43. Another window 44 defines the cuvette outwardly and separates it from the space 31 in the housing 24 which contains the filter 30 and the light detector (not shown). In this case, this detector measures the cuvette liquid subduing of the light from the light diode 42 as an expression of the conventration of sample liquid in the reagent liquid.

Claims

P a e n C l a i m s

1. A measuring system for use in continuous flow analysis of liquids and comprising a plurality of blocks of non-porous, stiff material, whose one side face is formed with a pattern of channels covered by a plate and connected to a flow cuvette, which is so positioned at one end of each block that it can be illuminated by a source of light and emit or pass on light to a light detector placed outside the block, c h a r a c t e r ¬ i z e d in that the blocks have such common outer dimensions and have the flow cuvette so disposed that each of them can be placed in a common, substantially box-shaped detector housing associated ith the system, said detector housing containing a light detector for detection of the light received from the cuvette.

2. A measuring system according to claim 1, c h a r a c t e r i z e d in that the detector housing is formed with a through opening through which a cuvette o a block placed in the housing may be illuminated.

3. A measuring system according to claim 2, c h a r a c t e r i z e d in that an exchangeable colour filter is placed over the opening.

4. A measuring system according to any of the preceding claims, c h a r a c t e r i z e d in that an axially movable, cylindrical metering valve body known per -se and having at least an annular groove is placed in a bore in each block, said metering valve body being movable between a filling position in which it communicates with a filling channel provided in the block, and an analysis position in which it communicates partly with a reagent channel provided in the block, partly with one end of the channel pattern of the block.