Determination of benzene and its homologues in hot melt adhesives by headspace gas chromatography-mass spectrometry

For accurate quantification of benzene and its homologues (toluene, ethylbenzene, p-xylene, m-xylene, o-xylene and styrene) in hot melt adhesives, a headspace gas chromatography-mass spectrometry (HS-GC/MS) method was established. Experiments were performed to optimize the conditions and parameters of headspace sampling, and GC/MS parameters. Fifteen samples of hot melt adhesives were analyzed with the established method. The results showed that:1) The optimized experimental conditions used 0.20 g samples of hot melt adhesives, followed by extraction in 1 mL glyceryl triacetate (matrix correction agent) with deuterated benzene internal standard (0.10 mg/L) addition. 2) The limits of detection for benzene and its homologues were 0.01-0.03 mg/kg. The precision of method ranged from 1.29% to 3.45% with the recoveries from 94.1% to 99.9%. 3) The levels of benzene and its homologues determined in the 15 samples varied. The detection rate of benzene was 13.3% with the level ranged from 0.03 to 0.04 mg/kg. The detection rates of toluene, ethylbenzene, p-xylene, m-xylene and o-xylene reached 100% with the levels ranged from 0.09 to 3.71, 0.15 to 0.29, 0.09 to 0.29, 0.16 to 0.50 and 0.15 to 0.47 mg/kg, respectively. The detection rate of styrene was 86.7% with the level ranged from 0.14 to 0.71 mg/kg. This method is simple, accurate, reliable and suitable for the routine determination of benzene and its homologues in hot melt adhesives.