Method and apparatus for automated quantitative fluid analysis

• US 3,876,374 A
• Filed: 03/22/1974
• Issued: 04/08/1975
• Est. Priority Date: 03/22/1974
• Status: Expired due to Term

• Current Assignee: Technicon Instruments Corporation (Bayer AG)
• Original Assignee: Donald A. Burns
• Inventors: Burns, Donald A.
• Primary Examiner(s): Serwin, R. E.
• Application Number:
  US05/453,896
• Time in Patent Office: 382 Days
• Field of Search: 23/253R,23R,23B,259 356/36
• US Class Current: 436/53
• CPC Class Codes: G01N 35/08 using a stream of discrete samples flowing along a tube system, e.g. flow injection analysis
• CPC Class Codes: Y10T 436/118339 with formation of a segmented stream

Abstract

Method and apparatus for reaction-rate analysis wherein a fluid sample, which has been treated to undergo a reaction, is flowed into a conduit and then flowed out of the conduit in the reverse direction so that the first sample portion which enters the conduit is the last sample portion to leave the conduit. The outflow of the conduit is to an analysis station wherein a constituent of interest of the sample is quantitatively analyzed.

Claims

1. A METHOD OF ANALYZING A FLUID SAMPLE FOR A CONSTITUENT OF INTEREST, COMPRISING THE STEPS OF:

FLOWING THE SAMPLE ALONG A FIRST CONDUIT PORTION AND OUTLETTING THE SAMPLE FROM SAID FIRST CONDUIT PORTION TO THE INLET OF A SECOND CONDUIT PORTION;

TREATING THE SAMPLE IN SAID SECOND CONDUIT PORTION TO EFFECT A RATE REACTION OF THE SAMPLE;

REVERSING THE FLOW OF THE TREATED SAMPLE IN SAID SECOND CONDUIT PORTION SO THAT THE TREATMENT TIME OF A TRAILING PORTION OF SAID SAMPLE ENTERING SAID SECOND CONDUIT PORTION IS LESS THAN THE TREATMENT TIME OF A LEADING PORTION OF SAID SAMPLE IN SAID SECOND CONDUIT PORTION;

AND ANALYZING THE SAMPLE AT A STATION ON THE REVERSAL OF THE FLOW IN SAID SECOND CONDUIT.

2. A method as defined in claim 1, further including incubating said sample while in said second conduit portion in a temperature-controlled condition.

3. A method as defined in claim 1, further including mixing of the sample while in said second conduit portion.

4. A method as defined in claim 1, wherein:

said analysis station comprises a flow cell for photometric analysis.

5. A method as defined in claim 2, wherein:

said incubating portion of said conduit is formed as a coil for delay of the fluid through such coil and mixing of the sample.

6. A method as defined in claim 1, wherein:

said sample is one of a series of samples flowing one after another along said first conduit portion, the samples being separated from one another, and further including flowing each sample along said second conduit portion and reversing the flow in the latter, one sample at a time.

7. A method as defined in claim 1, wherein:

said sample is one of a series of samples flowing one after another along said first conduit portion, the samples being separated from one another by immiscible fluid segments at least along said first conduit portion, and further including flowing each sample along said second conduit portion and reversing the flow therein, one sample at a time.

8. A method as defined in claim 6, further including the step of segmenting each sample with immiscible fluid segments in said first conduit portion.

9. A method as defined in claim 6, wherein:

said samples are separated from one another in said first conduit portion by immiscible fluid segments.

10. A method as defined in claim 6, further including the step of switching successive samples between said second and third conduit portions, and successively flowing from said second and third conduit portions the samples to said analysis station.

11. A method as defined in claim 5, wherein:

said samples are separated from one another in said first conduit portion by immiscible fluid segments which are removed prior to analyzing each sample.

12. A method as defined in claim 6, wherein:

said samples are separated from one another in said first conduit portion by immiscible fluid segments which flow through said analysis station in occluding manner, together with the samples.

13. A method as defined in claim 12, further including means to segment with an immiscible fluid each sample and means to remove all of said immiscible fluid segments prior to flow of the sample to said analysis station.

14. A method as defined in claim 7, wherein:

said second conduit portion has an open end, downstream from said first conduit portion, and further including flowing such an immiscible fluid segment preceding a sample out said open end of said second conduit portion prior to reversing the flow of the treated sample in said second conduit portion.

15. A method as defined in claim 14, further including flowing a wash solution into said open end of said second conduit portion following the reverse flow in the last-mentioned portion to cleanse said second conduit portion.

16. A method as defined in claim 15, further including segmenting with a gas said wash solution for washing out said second conduit portion.

17. Apparatus for analyzing a fluid stream for a constituent of interest, comprising:

sample source means;

means flowing the sample from said source means along a first conduit portion and outletting the sample from said first conduit portion to the inlet of the second conduit portion;

means treating the sample in said second conduit portion to effect a rate reaction of the sample;

means reversing the flow of the treated sample in said second conduit portion so that the treatment time of a trailing portion of said sample entering said second conduit portion is less than the treatment time of the leading portion of said sample in said second conduit portion; and

means analyzing the sample at a station on the reversal of the flow in said second conduit.

18. Apparatus as defined in claim 17, wherein:

said treating means comprises means incubating said sample while in said second conduit portion in a temperature-controlled condition.

19. Apparatus as defined in claim 17, wherein:

said second conduit portion comprises means for mixing the sample therein.

20. Apparatus as defined in claim 17, wherein:

said analysis station comprises a flow cell for photometric analysis.

21. Apparatus as defined in claim 17, wherein:

said means for flowing the sample along said first conduit portion comprising means separating the sample one from another in said first conduit portion by immiscible fluid segments which flow through said analysis station in occluding manner, together with the samples.

22. Apparatus as defined in claim 17, wherein:

said sample source means comprises means to separate said sample one from another in said first conduit portion by immiscible fluid segments.

23. Apparatus as defined in claim 17, further including means segmenting each sample with immiscible fluid segments in said first conduit portion.

24. Apparatus as defined in claim 17, wherein:

said second conduit portion is formed as a coil for delay of the fluid through such coil and mixing of the sample.

25. Apparatus as defined in claim 17, wherein:

said sample source means comprises a sampler having an aspirating probe associated therewith which aspirates successive ones, of a series of samples supported from said sampler, each of which is indexable at an off-take station of said probe, said probe under the influence of said means for flowing the sample along said first conduit portion, aspirating a gas segment prior to immersion into each sample and on leaving each sample, said sampler also having associated therewith a reservoir for wash solution and the probe being operative to aspirate wash solution from said reservoir between successive samples to form a segment of such solution between gas segments isolating successive samples.

26. Apparatus as defined in claim 17, further including means segmenting each sample with immiscible fluid segments in said first conduit portion.

27. Apparatus as defined in claim 17, wherein:

said sample is one of a series of samples flowing one after another along said first conduit portion the samples being separated from one another, said means for reversing the flow of the treated sample in said second conduit portion including means flowing each sample from said second conduit portion one after another.

28. Apparatus as defined in claim 17, wherein:

said sample from said sample source comprises a series of samples flowing one after another along said first conduit portion, the samples being separated from one another by immiscible fluid segments at least along said first conduit portion, and further including means flowing each sample along said second conduit portion and reversing the flow therein, one sample at a time.

29. Apparatus as defined in claim 17, wherein:

said sample source means provides a series of samples flowing one after another along said first conduit portion, the samples being separated from one another, each sample flowing in said second conduit portion and having its flow reversed therein, one sample at a time, and further including a third conduit portion for sample treatment similar to said second conduit portion, and means for switching successive samples flowing along said first conduit portion alternately between said second and third conduit portions, and successively flowing from said second and third conduit portions the samples to said analysis station.

30. Apparatus as defined in claim 23, further including means removing all of said immiscible fluid segments prior to flow of the sample stream to said analysis station.

31. Apparatus as defined in claim 26, wherein:

said second conduit portion has an open end, downstream from said first conduit portion, and said means for flowing the sample along said first conduit portion comprises means flowing such an immiscible fluid segment preceding a sample out said open end of the second conduit portion prior to said reversing of the flow of the treated sample in said second conduit portion.

32. Apparatus as defined in claim 29, wherein:

said means for switching successive samples comprises valve means automatically switching successive samples in phased relation to the arrival of such samples to said valve means.

33. Apparatus as defined in claim 31, further including means flowing a wash solution into said open end of said second conduit portion following the reverse flow in the last-mentioned portion to cleanse said second conduit portion.

34. Apparatus as defined in claim 33, further including means segmenting with a gas said wash solution for washing out said second conduit portion.