US 5,371,020 AGranted

Method of photometric in vitro determination of the content of an analyte in a sample

AssigneeRadiometer A/S

InventorPeter A. Frischauf

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Abstract

A method of photometric in vitro determination of the content of an analyte in a sample is disclosed. The sample is located in a measuring chamber which has a radiation path length and has at least one at least partially transparent wall part. The measuring chamber is in optical communication with an optical system adapted for the analyte which includes a radiation source and a radiation detector. The measuring chamber is adjustable in shape which enables the radiation path length across the measuring chamber to be changed. In a first measuring step an unknown first radiation path length across the measuring chamber is set and radiation at at least two wavelengths is transmitted from the radiation source through the measuring chamber and to the radiation detector. In a second step, the measuring chamber is adjusted in shape thereby setting a second unknown path length across the measuring chamber. Radiation at the same wavelengths as during the first step is again transmitted from the radiation source through the measuring chamber and to the radiation detector. The analyte content is then determined on the basis of radiation detected in each of the measuring steps.

Claims27

Dependent claims

A method of photometric in vitro determination of the content of an analyte in a sample, the method comprising:

A) providing a measuring chamber for holding the sample, the measuring chamber comprising at least one partially transparent wall in optical communication with the sample, wherein the measuring chamber receives radiation through the at least one partially transparent wall and transmits the radiation over a path having a path length through the sample and out of the chamber through the at least one partially transparent wall, a shape of the measuring chamber being adjustable for varying the path length through the chamber;
B) providing an optical system comprising a radiation source and a radiation detector;
C) mounting the measuring chamber in optical communication with the radiation source for transmitting radiation into the sample through the at least one partially transparent wall, and mounting the measuring chamber in optical communication with the radiation detector for receiving the radiation transmitted through the sample;
D) setting in a first measuring step a first unknown radiation path length through the measuring chamber, and transmitting radiation at at least two wavelengths from the radiation source through the measuring chamber and to the radiation detector;
E) in a second measuring step, adjusting the shape of the measuring chamber and thereby setting a second unknown radiation path length across the measuring chamber, and transmitting radiation at the same at least two wavelengths as used during the first measuring step from the radiation source through the measuring chamber and to the radiation detector;
and
F) determining the analyte content of the sample from the absorbance of the sample detected in each of the measuring steps, the determination being independent of the change in path length, the determination being made by solving simultaneous equations.

4 more elements

An analyzer for performing photometric in vitro determination of the content of an analyte in a sample, the analyzer comprising:

A) a measuring chamber for holding the sample, the measuring chamber comprising at least one partially transparent wall in optical communication with the sample, wherein the measuring chamber receives radiation through the at least one partially transparent wall and transmits the radiation over a path having a path length through the sample and out of the chamber through the at least one partially transparent wall, a shape of the measuring chamber being adjustable for varying the path length through the chamber;
B) an optical system comprising
i) a radiation source for generating at least two wavelengths of radiation, the at least one partially transparent wall of the measuring chamber being mounted in optical communication with the radiation source for receiving radiation at the at least two wavelengths from the source into the sample;
and
ii) a radiation detector for detecting the at least two wavelengths of radiation, the at least one partially transparent wall of the measuring chamber being mounted in optical communication with the radiation detector for transmitting the radiation of the at least two wavelengths through the sample and to the detector;
C) means for setting in a first measuring step a first unknown radiation path length through the measuring chamber, the radiation source transmitting radiation at the at least two wavelengths through the measuring chamber, the radiation detector detecting the radiation at the at least two wavelengths;
D) means for adjusting the shape of the measuring chamber and thereby setting a second unknown radiation path length across the measuring chamber in a second measuring step, the radiation source transmitting radiation at the same at least two wavelengths as during the first measuring step across the measuring chamber, the radiation detector detecting the radiation at the same at least two wavelengths;
and
E) means for determining the analyte content of the sample from the absorbance of the sample detected in each of the measuring steps by solving simultaneous equations, the determination being independent of the change in path length.

6 more elements

Dependencies are inferred from the claim text.

Facts

Application: 08/050,100Filed 7 May 1993
Priority: DK 1613/9119 Sep 1991
Granted: 6 Dec 1994
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

G01N 21/0303
Cuvette constructions: optical path conditioning in cuvettes, e.g. windows; adapted optical elements or systems; path modifying or adjustment
G01N 21/314
Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry:…
G01N 2021/036
Cuvette constructions: transformable, modifiable
G01N 2021/0364
Cuvette constructions: flexible, compressible