Analysis of Cationic Pesticides by Thin Layer Chromatography/Matrix - Assisted Laser Desorption Ionization Mass Spectrometry

This study demonstrates the analysis of pesticides by direct coupling of Thin Layer Chromatography (TLC) with Matrix-Assisted Laser Desorption Ionization mass spectrometry (MALDI). TLC-MALDI takes advantage of the high sensitivity of MALDI while utilizing the relatively quick and inexpensive separation offered by TLC. The optimization of a protocol to analyze cationic pesticides by TLC-MALDI is reported and tested on normal phase, reverse phase, and cellulose TLC plates. Detection limits in the picogram range were found for two analytes, phosphon and avenge. Detection limits for glyodin were in the nanogram range. Consistency in detection limits for each compound is observed on all types of stationary phases investigated. This demonstrates the applicability of this method for use on a variety of TLC plates.