Main content area

Determination of Benzene Series in Fish Based on Aqueous Two-Phase System for Samples Pretreatment

Deng, Qiaoqiao, Zhang, Xingmei, Li, Guizhi, Liu, Peipei, Liu, Yongming
Food analytical methods 2014 v.7 no.7 pp. 1513-1518
benzene, denaturation, detection limit, dialysis, fish, gas chromatography, new methods, spectroscopy, styrene, toluene, xylene
A novel method was developed for analyzing benzene series (benzene, toluene, ethylbenzene, xylene, and styrene; abbreviate as BTEXS) in fish sample by gas chromatography–mass spectroscopy (GC-MS), which was simplified the sample pretreatment process using matrix removal method by aqueous two-phase system (ATPS) of acetonitrile-K₂HPO₄-H₂O. The interaction of protein with BTEXS was investigated via the equilibrium dialysis coupled with GC-MS. The results of equilibrium dialysis indicated that the combination among BTEXS and protein was very strong. In suitable concentration of acetonitrile aqueous solution, a slow but full protein denaturation takes place, which causes the unfolding of protein and the release of BTEXS. Then, the BTEXS were extracted into upper phase of ATPS of acetonitrile-K₂HPO₄-H₂O with high extraction efficiencies. This method has been applied to the determination of seven benzene series (benzene, toluene, ethylbenzene, m-xylene, p-xylene, o-xylene, and styrene) residues in the fish sample. The detection limits were in the range of 1.1 ∼ 4.3 ng/g, and the spiked recoveries were 81.4 ∼ 97.8 %, with RSD 1.3 ∼ 5.1 %.