Determination of Volatile Fuel Oxygenates in Water by Gas Chromatography–Triple Quadrupole Mass Spectrometry: Effect of Automated Sample Preparation Techniques

Abstract

Considering the adverse effects of gasoline additives and aromatic compounds on the quality of the water supply and the ecological environment of the water, a methodology, with short chromatographic separation time (22.5 min) and high separation quality, was optimized for the determination of 11 common gasoline additives and aromatic compounds using gas chromatograph coupled with triple quadrupole mass spectrometer (GC–QqQ–MS/MS) system. The extraction procedure of analytes was performed by headspace solid–phase microextraction (HS–SPME) and purge and trap (P&T), respectively. Both of the two extraction methods provided excellent chromatographic resolution in subsequently GC–QqQ–MS/MS detection system, with the coefficients of linear regression of the calibration curves with HS–SPME and P&T pretreatments were 0.9965~0.9998 and 0.9961~0.9999, respectively, n = 7. The limit of detections (LODs) of these selected oxygenate compounds were discovered to be 0.52~32 ng/L in the P&T–GC–QqQ–MS/MS detection system and 0.11~151 ng/L in the HS–SPME–GC–QqQ–MS/MS detection system. For benzene, toluene, ethylbenzene and xylene isomers (BTEX), the HS–SPME–GC–QqQ–MS/MS system provided outstanding detection performance because of the lower LOD obtained. However, for other selected compounds, the P&T–GC–QqQ–MS/MS system offered lower LODs. The proposed extraction–detection procedure is a simple and sensitive analytical approach for the detection of gasoline additives and aromatic compounds in water.