Chemical apparatus and process disinfecting – deodorizing – preser – Analyzer – structured indicator – or manipulative laboratory... – Means for analyzing liquid or solid sample
Patent
1995-10-30
1997-12-09
Le, Long V.
Chemical apparatus and process disinfecting, deodorizing, preser
Analyzer, structured indicator, or manipulative laboratory...
Means for analyzing liquid or solid sample
422 63, 422 681, 422 1, 422100, 422104, 436 52, 436174, 436178, 436179, 436180, G01N 3508, B01D 6128
Patent
active
056957190
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a device for analyzing a fluid medium, in particular a liquid.
Fluid analyzers may be used for controlling chemical and biological processes such as the treatment of sewage water. It is desirable, for example, to lower the concentrations of nutritive salts, such as nitrogen and phosphate salts, in the effluent from waste water treatment plants. Proper control of the biological processes in the plant is required. It is therefore advantageous to be able to measure the amounts of phosphate, nitrate and ammonium in the waste water as they, amongst other variables, influence on or inform about the biological processes.
Numerous patents deal with the object of analyzing fluids, especially liquids, for the presence of various analytes. The measurement methods can in principle be divided into three groups: analyzed; the bulk process fluid, filtered and then at regular intervals automatically analyzed; entirely or partly immersed in the medium to be analyzed, or sampling is direct and analysis is carried out so close to the process, that the time between a sampling and the development of the analysis result is short enough to allow reliable, real-time control of the process.
An analyzing system for use in process control applications should enable the user to take immediate precautions; for example in waste water treatment, precautions against a suddenly increasing content of phosphates in the fluid medium. The methods in group (1) however are predominantly carried out in the laboratory which inevitably entails a delay in time from sample collection to actual analysis.
Moreover, as water samples are often analyzed spectrophotometrically, long transfer distances may present a further problem because the continuing biological activity in the samples tends to render them less representative. Even if the samples are transported quickly from the sampling site to the laboratory, the analysis results are somewhat uncertain because of problems relating to background turbidity in the samples.
Group (2) above includes UV measurements as well as ion selective electrodes and segmented flow analysis (SFA). The so-called flow injection analysis (FIA), belongs to group (2) as well as to group (1).
The segmented flow analysis (SFA) method was first described in U.S. Pat. No. 2,797,149 and No. 2,879,141, the basic principle being that the samples to be analyzed are separated from one another by air. A refinement of this technique comprising a fluid handling system is described in U.S. Pat. No. 4,853,336. This system is particularly useful for mixing liquid samples with previously separated processing liquids, such as reagents or diluents, in continuous flow analyzers. The system permits the delayed on-line mixing of different components of an analysis mixture, such as samples with reagents or diluents, as well as mixing and interaction of such components in a single conduit.
The basic FIA principle is outlined in U.S. Pat. No. 4,022,575 and No. 4,224,033. A metered amount of the sample is introduced in a moving liquid carrier flow, constituting a well-defined zone, the volume and geometry of which should be strictly reproducible. The sample zone within the carrier flow is transferred through an analysis module and detected in a suitable detection cell. In FIA the sample may be introduced directly in a predetermined amount, optionally using a valve, or it may be introduced using a system of magnetic valves, see e.g. U.S. Pat. No. 4,177,677.
Flow injection analysis requires that sample volumes be metered with great accuracy. This problem is addressed in EP published application 107 631 which describes integrated microconduits for flow analysis wherein a miniaturized system of channels is formed in a monolithic structure. A channel section is designed to be switchable between flow paths, thus allowing the metering of a sample volume by placing it in the switchable channel section while switched into sample flow, and then switching the channel section into analysis flow to process the sample volume in a
REFERENCES:
patent: 2913386 (1959-11-01), Clark, Jr.
patent: 3733177 (1973-05-01), Klein
patent: 4022575 (1977-05-01), Hansen et al.
patent: 4240912 (1980-12-01), Stumpf et al.
patent: 4837161 (1989-06-01), Stevens et al.
patent: 4920060 (1990-04-01), Parrent, Jr. et al.
patent: 4960711 (1990-10-01), Aoki et al.
patent: 4973561 (1990-11-01), Hansen et al.
patent: 5019515 (1991-05-01), Gisin et al.
patent: 5037737 (1991-08-01), Liffmann et al.
patent: 5389524 (1995-02-01), Larsen et al.
patent: 5434084 (1995-07-01), Burgess, Jr.
patent: 5525475 (1996-06-01), Ladouceur
Eisum Niels
Espensen Ib
Karlberg Bo
Kristensen Steen Gaardsted
Lynggaard Anders
Danfoss A/S
Le Long V.
Tecator AB
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