1978 年 19 巻 1 号 p. 34-43
Absorption coefficients at characteristic wavelengths on absorption and derivative spectra (1st and 2nd order) were obtained for 11 kinds of food colors and 2 kinds of similar dyes on the 0.02N ammonium acetate solutions ranging in concentration of these dyes from 0 to 20μg/ml. The time derivative method for 1st and 2nd derivative spectrophotometry was introduced and facilitate more the detection of each component in dye mixture for food from the shape of standard derivative spectrum (especially, the spectrum of 2nd-order derivative) than the ordinary derivative method with duochrometer, and also facilitate more accurately the determination of the component even in the case of turbid solution.
Several kinds of synthetic two-components mixture (each: 0-10μg/ml) were simply and rapidly identified and determined with the recoveries of 98-133% by 1st deravative spectrophotometry and of 99-106% by 2nd derivative method. For eight kinds of threecomponents mixture containing equal amounts of dyes (each: 33.3%), each component dye was also identified and determined with the recoveries of 86-112% by 2nd derivative spectra. This method was satisfactorily applied to the rapid analysis of food colors in seven kinds of commercial three-components mixture.