Simultaneous determination of neonicotinoid pesticides in tea-tree plantation soil by ultra-performance liquid chromatography tandem mass spectrometry

Tóm tắt

The quality of tea is influenced by many criteria related to farming methods, including soil characteristics and the use of chemical substances, typically pesticides or insecticides. The group of neonicotinoids (NEOs) is among the pesticides used in agriculture with the potential of accumulation in soils. In this study, the method for determining NEOs in tea-tree plantation soils was investigated and validated based on QuEChERS and UPLC-MS/MS as the sample preparation and measurement methods, respectively. The Acquity UPLC BEH C18 column (130 Å, 1.7 µm, 2.1 x 100 mm) (Waters Corporation) was used to serve the separation performed on the UHPLC System (UltiMate 3000, Thermo Fisher Scientific) coupled with tandem mass spectrometry (TSQ Endura, Thermo Fisher Scientific). The methods showed a proper linearity (R² > 0.995), an acceptable repeatability and reproducibility (%RSDs varied from 0.87-9.6 for both intra-day and inter-day), and high recoveries (81-102% for most of the spiked samples). The validated method was then applied to real soils collected from the tea plantations in the North (ancient tea plants) and South (organic and VietGAP), Vietnam. The results showed that undetected pesticide concentrations for northern soils and imidacloprid with its highest content (81.0 ) were recorded in the South.