A capillary electrophoresis microchip for the analysis of photographic developer solutions using indirect fluorescence detection

Abstract

A capillary electrophoresis microchip is developed for the rapid determination of 4-amino-3-methyl- N-ethyl-N-(β-methane sulfonamidoethyl)aniline (CD-3) in commercial colour photographic processing solutions and the applicability of the method is examined. The use of indirect fluorescence as an on-chip detection method is also demonstrated. Using a running buffer at pH 11.9 prepared from disodium hydrogenphosphate and fluorescein the quantitative determination of CD-3 is achieved, resulting in an analysis time of approximately 7 s. Under these conditions, a detection limit of about 5 mg L⁻¹ is obtained, with good linearity between signal and concentration over a range of 5–20 mg L⁻¹.