Method for correcting instrumental error of spectroscope of optical analyzer

• US 5,592,290 A
• Filed: 11/14/1994
• Issued: 01/07/1997
• Est. Priority Date: 11/12/1993
• Status: Expired due to Fees

• Current Assignee: Fuji Photo Film Co Limited (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Photo Film Co Limited (Fujifilm Holdings Corporation)
• Inventors: Yamada, Kiyoshi, Arai, Fuminori, Amano, Yoshikazu
• Primary Examiner(s): McGraw, Vincent P.
• Assistant Examiner(s): HANTIS, KAREN
• Application Number:
  US08/358,486
• Time in Patent Office: 785 Days
• Field of Search: 356/300, 356/319, 356/445-448, 356/323, 356/325, 356/326, 356/328, 356/418, 356/243, 356/402, 356/309, 356/346, 356/434-435, 356/32-35, 356/35.5, 356/431 , 356/436, 364/497-498, 364/571.01-571.08, 364/526, 364/525, 364/558, 364/572-582, 436/43, 436/47, 436/164, 422/63-67, 250/363.09, 73/1 R
• US Class Current: 356/300
• CPC Class Codes: G01N 21/274 Calibration, base line adjustment, drift correction
• CPC Class Codes: G01N 21/8483 Investigating reagent band test-element handling not specific to a test method G01N33/4875; analytical elements specific to chemical analysis of biological material G01N33/52; autometer with reagent band G01N35/04

Abstract

A method for correcting an instrumental error due to wavelength error of a spectroscope of an optical analyzer for measuring an optical density reflected from or transmitted through a dry analysis element. One standard color plate having a standard optical density OD_ST is measured by an optical analyzer to be corrected to obtain an measured value OD_M. A measured optical density OD_S of the element applied with a sample through the optical analyzer to be corrected is corrected by using a ratio of OD_M /OD_ST to obtain a corrected measured value OD_C of the sample. The standard color plate to be used contains an indicator dye contained in the non-reacted dry analysis element or a dye having an absorption spectrum same as or similar to that of the indicator dye in the measurement wavelength range. Another correction method in consideration of a layer coefficient of a dry analysis element is also provided.

Claims

1. A method for correcting an optical density measurement having an instrumental error, the optical density measurement to be corrected being of a sample using a first optical analyzer having an unknown instrumental error, said sample being prepared from a dry analysis element containing a first dye having an absorption spectrum and having been contacted with a sample solution containing an analyte, the method comprising the steps of:

selecting a standard color plate of a second dye selected from the group consisting of;

a reference dye which is the same as said first dye; and

a dye which has an absorption spectrum similar to the absorption spectrum of said first dye;

measuring and recording a standard optical density of said standard color plate using a second optical analyzer having a known instrumental error;

measuring and recording the optical density of said standard color plate using said first optical analyzer to be tested;

measuring and recording the optical density of said sample using said first optical analyzer to obtain said,optical density measurement to be corrected;

calculating a corrected optical density of said prepared sample using the equation;

space="preserve" listing-type="equation">OD.sub.C =(OD.sub.ST /OD.sub.M)×

OD.sub.S ;

where OD_C represents said corrected optical density, OD_ST represents said optical density of said standard color plate as measured by said second optical analyzer, OD_M represents the optical density of said standard color plate as measured by said first optical analyzer, and OD_S represents the optical density of said sample as measured by said first optical analyzer.

2. A method for correcting an optical density measurement having an instrumental error, the optical density measurement to be corrected being of a sample using a first optical analyzer having an unknown instrumental error, said sample being prepared from a dry analysis element containing a first dye having an absorption spectrum and having been contacted with a sample solution containing an analyte, the method comprising the steps of:

selecting a standard color plate of a second dye selected from the group consisting of;

a reference dye which is the same as said first dye;

a dye which has an absorption spectrum similar to the absorption spectrum of said first dye; and

,

a dye having an absorption spectrum similar to an absorption spectrum of said first dye after contact with said sample solution;

measuring and recording a standard optical density of said standard color plate using a second optical analyzer having a known instrumental error;

measuring and recording the optical density of said standard color plate using said first optical analyzer;

measuring the optical density of said sample using said first optical analyzer to obtain said optical density measurement to be corrected;

calculating an instrumental error correction coefficient gradient of wavelength using the equation;

space="preserve" listing-type="equation">Φ

=(OD.sub.ST -L)/(OD.sub.M -L);

where Φ

represents the instrumental error correction coefficient gradient of wavelength, OD_ST represents said optical density of said standard color plate as measured by said second optical analyzer, L represents a predetermined layer coefficient of said dry analysis element, and OD_M represents the optical density of said standard color plate as measured by said first optical analyzer;

calculating an instrumental error correction coefficient intercept using the equation;

space="preserve" listing-type="equation">Λ

=[(OD.sub.M -OD.sub.ST)/(OD.sub.M -L)]×

L;

where Λ

represents the instrumental error correction coefficient intercept, OD_ST represents said optical density of said standard color plate as measured by said second optical analyzer, L represents a predetermined layer coefficient of said dry analysis element, and OD_M represents the optical density of said standard color plate as measured by said first optical analyzer; and

,

calculating a corrected optical density of said sample using the equation;

space="preserve" listing-type="equation">OD.sub.C =Φ

×

OD.sub.S +Λ

;

where OD_C represents said corrected optical density, Φ

represents the instrumental error correction coefficient gradient of wavelength, OD_S represents the optical density of said sample as measured by said first optical analyzer, and Λ

represents the instrumental error coefficient intercept.

3. The method of claim 2 wherein said layer coefficient equals zero.

4. The method of claim 2 wherein said instrumental error correction coefficient intercept is a predetermined value.

5. The method of claim 4 wherein said instrumental error correction coefficient intercept equals zero.

6. The method of claim 2 wherein said standard color plate is a dry analysis element not having been in contact with a sample solution.