Development of a fast multiresidue method for the determination of pesticides in dry samples (wheat grains, flour and bran) using QuEChERS based method and GC–MS

In this study a multiresidue method for the determination of 24 pesticides in wheat, white flour and bran using gas chromatography coupled to mass spectrometry with negative chemical ionisation and selected ion monitoring (GC–MS (NCI–SIM)) was developed and validated. The QuEChERS method was used for the extraction of different pesticides. The method was validated evaluating the following parameters: linearity, limit of detention, limit of quantification, matrix effect as well as precision and accuracy, evaluating the percentage of recovery at four different spike levels. The linear range used in the calibration curves was from 1.0 to 100 μg L−1 for wheat and 2.0 to 200 μg L−1 for flour and bran, both with values of r2 > 0.99. The recoveries had been considered satisfactory presenting values between 70% and 120% with RSD < 20% for the majority of compounds.