Simultaneous Determination of BTEX and Gasoline Oxygenates in Water by P&T-GC-QqQ-MS/MS

A method for the simultaneous determination of 12 BTEX and gasoline oxygenates in water was developed based on purge-and-trap (P&T) sampling combined with gas chromatography-triple quadrupole mass spectrometry (GC-QqQ-MS/MS). The parameters of P&T sampling, such as purge temperature and resolution time, were optimized based on the US EPA method 8260. Precursor ions and product ions for the 12 analytes in the multiple reactions monitoring (MRM) mode were identified and the collision energy for the 12 analytes were optimized. The linear ranges of 12 analytes ranged from 0.05 μg·L-1 to 20 μg·L-1 with detection limits (3S/N) in the range of 0.52-32 ng·L-1 and the lower limits of determination (10S/N )in the range of 1.6-96 ng·L-1. Recovery rates obtained by standard addition method were in the ranges of 80.2%-120%, the intra-day RSDs (n=5) and inter-day RSDs (n=6) were in the range of 2.0%-8.9% and 1.2%-13%, respectively.