Automated flow injection measurement of photographic dyes in gelatin at elevated temperatures

Abstract

A method of measuring spectrophotometrically the concentrations of photographic dyes is described. The problems of analysing the highly concentrated, non-aqueous dyes when dispersed in a highly viscous gelatin matrix were solved by the use of a flow injection analysis system which performed automated dissolution and dilution using the split zone-gradient chamber method at elevated temperatures with dimethyl sulphoxide as the system carrier stream. The requirement of maintaining the matrix in which the dyes are located at an elevated temperature was met by housing the fluid bearing portion of the system within an incubator oven, with remote computer control and remote detection via optical fibres. The precision of the dilutions gave a relative standard deviation of 2% or better for dilutions up to 2000-fold of the injected sample. When compared with manual dilution and measurement, agreement was within 5% for all samples.