| A gas chromatography-triple quadrupole mass spectrometric(GC-MS/MS)method for the determination of 7 pyrethroid pesticide residues in tea was developed using dispersive solid phase extraction and dispersive liquid-liquid microextraction(d-SPE-DLLME) as sample preparation methods. The samples were extracted with acetonitrile，purified with primary secondary amine(PSA) and multi-walled carbon nanotubes(MWCNTs) as sorbents，concentrated into carbon tetrachloride(CCl4)，and analyzed by GC-MS/MS. The effects of different kinds of extractants, volume and types of extractants, volume of dispersants and extraction time on extraction efficiency were investigated by using full fermented black tea as the matrix. In the experiment, acetonitrile was used as extractant in d-SPE，200μL of CCl4 was used as extractant, 1 mL of acetonitrile was used as dispersant，and extraction time was 1 min in DLLME. The results showed that the calibration curves of 7 pesticides were linear in the range of 10-500μg/kg，and the limits of quantitation were 1.0-10.0μg/kg. The average recoveries of 7 pesticides in four kinds of tea(black tea，green tea，oolong tea and dark tea) at four spiked levels were in the range of 75.4%-113.6%.The relative standard deviations(RSD,n=5) were not more than 8.8%.The proposed method showed the advantages of simplicity, rapidness, low cost and low detection limit, and was successfully applied in the detection of twelve commercially available tea samples. |