Multiclass Pesticide Analysis in Vegetables Using Low-Pressure Gas Chromatography Linked to Tandem Mass Spectrometry

A method for determining pesticide residues in vegetables by low-pressure gas chromatography- tandem mass spectrometry (LPGC-MS/MS) is proposed after a fast and simple extraction of the vegetable with dichloromethane and without cleanup steps. The technique reduces the total time required to determine 72 pesticides to less than 31 min, increasing the capability of a monitoring routine laboratory with respect to conventional capillary GC. The use of a guard column and a carbofrit plug into the glass liner in combination with LPGC avoids previous cleanup steps, simplifying the manipulation of the sample and reducing time, cost, and uncertainty of the final result. The method presents limits of quantitation (LOQs) low enough to determine the pesticide residues at concentrations below the maximum residue levels stated by legislation.