| Headspace solid-phase microextraction(HS-SPME) combined with gas chromatography-triple quadrupole mass spectrometry(GC-MS/MS) was used for the rapid determination of 11 amide herbicide residues in tea.Various factors affecting extraction performance such as the types of extraction coatings,the type of inorganic salt,water consumption,salt dosage,extraction temperature and extraction time in HS-SPME were optimized by using the all fermented black tea matrix.Under the optimized conditions,four kinds of teas,i.e.geen tea,oolong tea,black tea and puer tea were selected for methodology validation.The results showed that the calibration curves of 11 amide herbicides were linear in the range of 1-1 000 μg/kg,with correlation coefficients(r2) of 0.992 5-0.999 9,and the limits of quantitation ranged from 1 μg/kg to 10 μg/kg.The average recoveries of the 11 pesticides in black tea,green tea,oolong tea and dark tea at three spiked levels were in the ranges of 70.3%-119.1%,85.2%-118.7%and 74.6%-113.3%,respectively.The relative standard deviations(RSDs) were all not more than 17.4%(n=5).With the advantages of simplicity,rapidness,high sensitivity and good reproducibility,the method could meet the requirements of detection of 11 amide herbicide residues in tea. |