Determination of colour developing agents in photographic processing solutions using fixed-volume single-use sensorsPresented at SAC 99, Dublin, Ireland, July 25–30, 1999.

Abstract

An electrochemical method for the determination of colour developing agents in photographic processing solutions using single-use sensors is described. The sensor consists of two parts: the transducer, based on a screen-printed carbon (working and reference) and gold (counter) three-electrode configuration; and a sampler/electrochemical cell. The parts fit together to give a single-shot sampling and measurement device. The sensors were used to monitor the concentrations of the colour developing agent CD-4 (i.e. 4-(N-ethyl-N-2-hydroxyethyl)-2- methylphenylenediamine sulfate) in a photoprocessor. Comparison with HPLC data showed that there was a good correlation between the two methods (R² = 0.97). The sensor method was more convenient to use than HPLC and enabled measurements to be carried out at the photoprocessor without need to send samples to a laboratory for analysis.