Differentiation and quantification of xylene isomers by combining headspace solid‐phase microextraction/gas chromatography and self‐ion molecule reaction in an ion trap tandem mass spectrometry

A headspace solid‐phase microextraction (HS‐SPME) method using polydimethylsiloxane (PDMS)‐coated fiber coupling with GC/self‐ion molecule reaction (SIMR)/MS/MS (GC/SIMR/MS/MS) has been developed for the differentiation of o ‐, m ‐, and p ‐xylene isomers. The optimization parameters of this method are: extraction time 20 min, stirring rate 1200 rpm, sampling temperature 28°C, and salt concentration 5%. The LODs were found to be in the range of 3–9 ng/mL under the SIM mode of GC/MS. The RSDs were below 1% ( n = 5). The linear dynamic range of the calibration curve was from 0.05 to 10.0 μg/mL with correlation coefficient ( r 2 ) > 0.9089. The advantages of this technique are sensitive, selective, ease of operation, simple device, solvent free, and extremely little sample consumption. This technique is the first example using SIMR combined MS/MS applied in the GC/MS and it can be applied to other volatile compounds for future application.