Stir bar sorptive extraction and thermal desorption-gas chromatography-mass spectrometry for trace analysis of benzophenone and its derivatives in water sample

摘要

A simple and highly sensitive method called stir bar sorptive extraction (SBSE)and thermal desorption (TD)-gas chromatography-mass spectrometry (GC-MS), which is used for the determination of trace amounts of benzophenone (BP)and its derivatives, 2-hydroxy-4-methoxybenzophenone (BP-3)and 2-hydroxy-4-methoxy-4'-methylbenzophenone (BP-10), in river water samples, is described.A stir bar coated with polydimethylsilox-ane (PDMS)is added to a 10 ml water sample and stirring is carried out for 120min at room temperature (25 deg C)in a vial.Then, the PDMS stir bar is subjected to TD-GC-MS.The detection limit is 0.5-1 pgml~(-1)for BPs.The method shows good linearity and the correlation coefficients are higher than 0.997 for all the analytes.The average recoveries of the BPs are equal to or higher than 98.5% (R.S.D.:1.5-5.1%).This simple, accurate, sensitive and selective analytical method may be used in the determination of trace amounts of BPs in river water samples.