Management of Calibration Curves in the Absorptiometric Analysis

Abstract

The principle of the absorptiometric analysis depends on the fact that the optical characteristics ofsample solution obeys the Lambert-Beer's law.
The gradient of calibration curve, according to the law is constant under the same analyticalcondition.
In the ordinary analysis, the average gradient of calibration curve, which was obtained with theempirically and theoretically reliable measures, was defined as the basic gradient, and the straight linedrawn through the origin with the basic gradient was named as the basic calibration curve here.
The average blank value of each day, gained by the analysis of standard samples, was subtractedfrom absorbances of test samples and then the contents were read on the basic calibration curve.
By applying this method to the analyses of Si, P, Ni, Mo, W, Ti, Co, and Cu, the daily deviationof gradient was eliminated and the better analytical precision was obtained.
With a statistical treatment of data on standard samples it was easily capable of checking out theabnormal point on the daily process of analysis and ascertaining the stability of calibration curveduring a long period.