LC-MS METHODS FOR TRACE DETERMINATION OF PESTICIDES IN ENVIRONMENTAL-SAMPLES

An important advance for the trace determination of pesticides in real samples has been achieved by the use of highly sensitive techniques s uch as Liquid Chromatography-Mass Spectrometry (LC-MS). On the other h and, the combination of a trace enrichment procedure such as solid-pha se extraction (SPE) together with LC-MS improves the analyte detectabi lity at the low ppt level of concentration, often required in environm ental analysis. Several interfaces have been widely applied for the de termination of many pesticides in environmental samples. In this overv iew, applicability of some interfaces such as Particle Beam (PB), Atmo spheric Pressure Chemical Ionization (APCI) and Electrospray (ESP), is given in terms of sensitivity, structural information and type of com pounds to be analyzed. Examples on the trace determination of pesticid es in natural waters and sediment samples will be presented. Finally, recommendations about the most appropriate interfaces for each pestici de group are given.