Determination of multi-pesticides residues in jasmine flower and its scented tea

Abstract

For minor crops such as jasmine, the lack of pesticide registration and maximum residue limits are important issues that need to be solved in order to facilitate trading and ensure food safety. Meanwhile, reliable and quick analytical methods for multi-pesticide residues in these commodities are few, but required by various stakeholders. In this study, a method for detecting 25 of the most frequently used pesticides in jasmine flower and its scented tea by multi-plug filtration cleanup and ultra-high-performance liquid chromatography-tandem mass spectrometry was developed and validated. The cleanup process was optimized and compared with the dispersive solid phase extraction procedure. Results showed that the relative standard deviations of multi-plug filtration cleanup method in precision tests were smaller. The absence of any solvent evaporation, vortices and additional centrifugation processes made this approach more rapid. The method was validated, showing that except for methomyl, recoveries of 25 pesticides were 64–108%, with relative standard deviations (n = 5) of 0.33-10%. The method was successfully applied to detect pesticide residues in marketed jasmine flower and scented tea samples. The results showed that some samples contained a combination of different residues, with neonicotinoids, organophosphates and pyrethroids being the three main types detected in both flower and tea samples.