a b s t r a c t
Two methods based on gas chromatography coupled with mass spectrometry and tandem mass spectrometry
analyzers are described for the identification, confirmation and quantitation of two EU-banned
insecticides: isocarbophos and isofenphos-methyl, detected in recent monitoring programmes in pepper
samples. The proposed methodologies involved a liquid–liquid extraction with acetonitrile followed by a
cleanup step by dispersive solid-phase extraction using primary–secondary amine as sorbent material.
Recovery studies performed on peppers spiked at different fortification levels (10 and 50 lg kg1) yielded
average recoveries in the range 85–98% with RSD values below 8%. Identification, confirmation and quantitation
were carried out by gas chromatography/mass spectrometry (GC–MS) in selected ion monitoring
mode and gas chromatography/tandem mass spectrometry (GC–MS/MS) using an ion trap operating in
the multiple reaction monitoring (MRM) mode. The obtained limits of detection (LODs) were in the range
0.1–0.3 lg kg1, depending on the technique. The proposed methods were successfully applied to the
analysis of suspected pepper samples.