Development of an analytical method for pesticide residues in berries with dispersive solid phase extraction using multiwalled carbon nanotubes and primary secondary amine sorbents

Abstract

A dispersive solid phase extraction using primary secondary amine and multi-walled carbon nanotubes as a mixed sorbent material was developed for the multiple pesticide residue analysis of berry samples. Gas chromatography-mass spectrometry analysis in selected ion monitoring mode was used for the determination of multiple pesticide residue levels in berry samples. In this study, strawberry, raspberry, blueberry and blackberry were selected as representative matrices. In the sample preparation process, the chosen extraction solvent was acetonitrile and inorganic salt was added to partition pesticide residues into the acetonitrile phase. The cleanup step was carried out by dispersive solid phase extraction based on a mixture of primary secondary amine and multi-walled carbon nanotubes to remove interferences in the extracts. After further optimization of the sample preparation and determination steps, the percentage recovery was in the range of 71% to 123% with an intra-day precision of less than 13% and inter-day precision of less than 20% in most cases. The proposed method was used successfully for the quantitative determination of pesticide in commercial berry samples.