Application of Gas Chromatography Tandem Mass Spectrometry to Simultaneous Determination of 141 Pesticide Residues in Teas.

Tea is one of the world’s most popular healthy drinks; the tannin and γ-aminobutyric acid contained in tea can work as antibacterial agents, help lower blood pressure, and counteract alcohol. Research in the past decade has indicated that steeping tea leaves at high temperatures can introduce pesticide residue into the tea, which has led to increased awareness of food safety amongst consumers and of the problem of pesticide residue on tea leaves. Out of concerns for food safety, many tea importing countries have set maximum residue limits (MRLs) for the maximum amount of pesticide residue allowance on tea leaves, and over recent years, MRLs have been decreasing. In order to produce high quality and safety tea products as well as meet the requirements of importing countries, developing fast and accurate analysis method of pesticide residue in tea is required. The aim of the present study was to establish the technique of analysis method of 141 pesticide residues in tea by solid-liquid extraction and gas chromatography tandem mass spectrometry (GC/MS/MS) in multiple reaction monitoring (MRM) mode. The experimental results revealed that the instrument detection limit (IDL) and method detection limit (MDL) of 141 pesticides analyzed by GC/MS/MS were 0.01-7.22 μg L^-1 and 10-100 μg L^-1. In addition, the recoveries of 109 pesticides ranged between 60 and 140% at one spiked concentration levels of 100 μg kg^-1 in triplicate and the relative standard deviation (RSD) of 134 pesticides were lower than 20%. The established method could be not only successfully accomplished in 42 minutes, but also has been successfully applied to determine pesticides residues in real tea samples and the results could provide to relevant authorities for reference in work on tea cultivation.