[Determination of pesticide residues in substitutional tea by dispersive solid-phase extraction and gas chromatography-triple quadrupole mass spectrometry].

OBJECTIVE: The method was established for determination 14 kinds of psticide residues in substitutional tea using gas chromatography-triple quadrupole mass spectrometry( GC-MS/MS) for instrument method and dispersive solid-phase extraction( dSPE) for sample preparation. METHODS: The samples extracted with acetonitrile, and purified by N-propyl ethlene diamine( PSA), the extracts were separated on DB-5MS column( 30 m × 0. 25 mm, 0. 25 μm) with programmed temperature and determined by GCMS/MS in multi-reaction monitoring( MRM) model. The external standard method was applied to quantify the pesticides. RESULTS: The method showed a good linearity( r ≥0. 999) in certain ranges for 14 kinds of pesticides. The limits of quantification( LOQ)were 4-40 μg/kg. The average recoveries range were 65. 6%-116. 6% in three add levels of 20, 40 and 200 μg/kg, and relative standard deviations( RSD S) of 1. 5%-15. 7%( n = 6). CONCLUSION: This method is simple, fast, sensitive, selective and can satisfy the request of simultaneous analysis of multiple pesticide residues in substitutional tea.