초록 ▼

A method and apparatus are described for the determination of an analyte in an aqueous liquid while eliminating the biasing effect of unknown interferents which are preformed or formed in situ during the determination. The method comprises physically contacting a sample of the liquid with an interac

A method and apparatus are described for the determination of an analyte in an aqueous liquid while eliminating the biasing effect of unknown interferents which are preformed or formed in situ during the determination. The method comprises physically contacting a sample of the liquid with an interactive composition for the analyte; measuring the spectrophotometric responses generated by such contact at a primary wavelength l1 and one or more secondary wavelengths l2, l3, . . . ln; and determining analyte concentration or activity using the equation: C=a0+a1[A1+a1A2+. . . +an-1An] wherein C is analyte concentration or activity, A1, A2, . . . An are the spectrophotometric responses observed at l1, l2, . . . ln, respectively; and a0, a1, and a1, a2, . . . an-1 are constants determined according to a calibrating method, also described herein. Such calibrating method is an empirical means for determining and recording in a chemical analyzer the a0, a1, and a1, a2, . . . an-1 constants essential for making the analyte determination.

대표청구항 ▼

A chemical analyzer for the determination of an analyte in an aqueous liquid in contact with an interactive composition for said analyte; said analyzer comprising means for measuring the spectrophotometric responses A1, A2, . . . An at, respectively, a primary wavelength l1 and at n secondary wavele

A chemical analyzer for the determination of an analyte in an aqueous liquid in contact with an interactive composition for said analyte; said analyzer comprising means for measuring the spectrophotometric responses A1, A2, . . . An at, respectively, a primary wavelength l1 and at n secondary wavelengths selected from the secondary wavelengths l2, l3, . . . ln; and means for determining the concentration or activity C of said analyte using the equation (I): C=a0+a1(A1+a1A2+. . . +an-1An) wherein the constants a0, a1 and a1, a2, . . . an-1 and said secondary wavelengths l2, l3, . . . ln are determined according to a calibration method for as many n secondary wavelengths as are used, said calibration method comprising the steps: (A) from a multiplicity of patient test samples of unknown analyte concentration or activity, identifying first and second patient test samples having substantially the same analyte concentration or activity, said first sample exhibiting a significant bias in analyte concentration or activity and said second sample exhibiting no significant bias in analyte concentration or activity measured at a primary wavelength l1; (B) making a spectral absorption scan of each of said samples identified in step A; (C) identifying absorption bands from said spectral scans where differences in absorbance between said scans can be observed, and selecting at least one secondary wavelength from the group of secondary wavelengths l2, l3, . . . ln representative of said absorption bands of both said first and second patient samples, respectively, wherein n represents the number of absorption bands; (D) using a multiplicity of patient test samples of known analyte concentration or activity, determining a linear regression line and its intercept and slopes using the equation (II): C=a0+a1A1+a2A2+. . . +anAn wherein C is analyte concentration or activity; a0 is the intercept of said line; A1, A2, . . . An are the spectrophotometric responses measured at l1, l2, . . . ln respectively; and a1, a2, . . . an are the slopes of said line relating said spectrophotometric responses at l1, l2, . . . ln, respectively, to said analyte concentration or activity; (E) using the results of step D to determine constants a1, a2, . . . an-1 for said equation (I) above using the equation (III): ai=(ai+1)/a1 wherein i=1 to (n-1); and (F) recording in said analyzer the values of said constants a0, a1, and a1, a2, . . . an-1 for use in equation I above.