Fast GC-MS of endocrine disrupting chemicals

An analytical method has been developed and evaluated for the determination of endocrine disrupting chemicals (EDCs) - pesticides in non-fatty food. Twenty-nine analytes of different chemical classes according to EDCs draft list of European Commision were selected. The method is based on fast GC-MS with bench top quadrupole MS detector and electron impact (EI) ionisation (70 eV). For the effective separation programme temperature vaporiser (PTV) injector and narrow-bore column were used. Slightly modified QuEChERS sample preparation technique was applied for the preparation of apple extracts for matrix-matched standards, synthetic sample and real sample extracts. Two internal standards (I. S.) - heptachlor (HPT) and triphenylphosphate (TPP) - were used. The results needed for the method validation were calculated from absolute peak areas and normalised areas to HPT and TPP. The important part of the study is the utilisation of analyte protectants (APs). Three calibrations approaches: matrix-matched standards without/with APs and acetonitrile (MeCN) standards with APs were used. The best results were obtained with matrix-matched standards without APs. The developed and validated analytical method was used for the identification and quantification of EDCs pesticides in real samples (orange, lettuce, strawberry and plum).