A rapid multi-residue method for pesticide residues determination in white and black pepper (Piper nigrum L.)

The current analytical methods for pesticide residues determination in white and black pepper are laborious and time-consuming. A rapid multi-residue method was developed to determine 16 organochlorine and pyrethroid pesticide residues in white and black pepper using gas chromatography with electron capture detector. All pesticides were extracted and partitioned with acetonitrile. The extract was cleaned up with silica gel packed in a Pasteur glass pipette to remove matrix interferences due to volatile oils. Recoveries of the pesticides fortified at 0.01, 0.1 and 0.5 mg kg−1 ranged from 86.8 to 118% with relative standard deviation of less than 11.0%. The limit of detection for most of the pesticides studied was 0.002 mg kg−1. This method has high selectivity for pesticides in white and black pepper which contain different amounts of volatile oils. The method developed was successfully used to analyse 20 pepper samples purchased from the local markets in Kuching, Malaysia and all the residues detected were below the permitted levels of European Union.