The Use of Orthogonal Functions to Correct for Irrelevant Absorption in Two Component Spectrophotometric Analysis

Abstract

Abstract General procedures are outlined for the use of orthogonal functions to correct for irrelevant absorption in two component spectrophotometric analysis. In adapting a traditional method to the use of orthogonal functions, the essential modification occurs at the final stage of calculation, when it is necessary to substitute suitable analogues for the entities, “extinction” and “wavelength.” Thus, extinction is replaced by coefficient of an orthogonal function and wavelength by orthogonal function over a specified range (or set) of wavelengths. Once these substitutions have been made, orthogonal functions may be readily incorporated into the usual methods and equations of spectrophotometric analysis. Although the procedures are specified in terms of Legendre polynomials (as used by Ashton and Tootill, 1956), they are equally applicable to the use of trigonometric functions, which may have a major role to play in future developments. The above general procedures are illustrated by the analysis of a mixture of adrenaline and phenol.