Non-target Rapid Screening of Unknown Pesticide Residues in Tea Beverage

A dispersive liquid-liquid microextraction (DLLME) coupled with high performance liquid chromatography-quadrupole-time of flight mass spectrometry (HPLC-Q-TOF/MS) method was developed for screening of unknown pesticide residues in tea beverage. 13 kinds of quality-controlled compounds were used as indicator to optimize this method. The target compounds in samples were cleaned by 2 g PSA,extracted by 200 μL trichloromethane and dispersed by methanol in shaking table and separated on a C18 column,and determined by HPLC-Q-TOF/MS.The average recoveries were between 83.1%~96.8%,and RSD ranged from 0.88%~4.82%.The matrix calibration curves showed good linearity in the range of 2.0~400 μg/L,the coefficient of determination was above 0.9989,the limits of detection (LOD,S/N=3) was 0.002~0.092 μg/kg,and the limits of quatitation (LOQ,S/N=10) was 0.006~0.307 μg/kg. This method can quickly screen pesticide residues in tea beverage without reference standards,and can be applied to the actual screening of tea beverage samples. This method is fast,accurate and has high throughput,which can meet the requirement for non-target rapid screening of pesticide residues in tea beverage.