Determination of aldicarb and its metabolites in peanuts by high performance liquid chromatography-linear ion trap triple stage mass spectrometry

Abstract

A high performance liquid chromatography-linear ion trap triple stage mass spectrometry (HPLC-IT/MS3) method was established to detect aldicarb, aldicarb sulfoxide, and aldicarb sulfone in peanuts. The samples were extracted by acetonitrile saturated with cyclohexane, followed by clean-up with gel permeation chromatography (GPC). The determination was performed using HPLC-IT/MS3 for the identification and quantification of the compounds. The separation was carried on a Capcell PAK CR column with gradient elution using 5 mmol/L acetic acid/ammonium acetate/acetonitrile as mobile phase. The ionization of molecules was performed by electrospray mode. Selective reaction monitoring (SRM) was the acquisition mode used for the monitoring of MS3 transitions for each compound using aldicarb-d3 as internal standard for three analytes. Matrix effects were evaluated by comparing the recovery of matrix-matched and solvent-based calibration curves. The calibration graphs were linear in the ranges of 10 - 500 microg/L and the detection limits ranged from 4 to 5 microg/kg. The average recoveries ranged between 81.5% and 115% at three different spiked levels (10, 20 and 40 microg/kg). Satisfactory results were obtained in the determination of real peanut samples by this method.