Matrix‐assisted laser desorption/ionization combined with quadrupole ion‐trap mass spectrometry for the direct analysis of colour couplers adsorbed on solid substrates

A method has been developed for the study of samples adsorbed on solid substrates using matrix‐assisted laser desorption/ionization combined with quadrupole ion‐trap mass spectrometry. The introduction of ions generated externally to the ion trap facilitates the direct analysis of molecules contained on substrates without the need for a lengthy extraction procedure. The method is demonstrated for the analysis of colour coupler compounds separated by thin‐layer chromatography and present on a photographic substrate.