FOOD CHEMICAL ANALYSIS BY LASER DESORPTION AND RESONANT IONIZATION MASS SPECTROMETRY

Abstract

An overview of the recent work on food chemical analysis implemented with laser techniques from our laboratory is presented. Emphasis is made on non-volatile compound analysis as it requires direct vaporisation without fragmentation prior to ionisation. Thus, a central part of the article is dedicated to the new laser desorption coupled with resonance-enhanced multiphoton ionisation and the time-of-flight mass spectrometric (LD + REMPI + TOFMS) technique. Basic features are described with special relevance to its high selectivity, based both in mass spectrometry and laser ionisation resolution, as well as to its great sensitivity of the order of a few tens of nanograms and detection limits of few picograms. Selected analytical examples are presented like the pesticide content of agricultural samples, as carbendazim in peppers, and healthy food compounds, as resveratrol in grapes. A comparison with currently used analytical methods is provided in order to critically assess the potentiality of the technique.