Analysis and Evaluation of 7 Indictor Polychlorinated Biphenyls (PCBs) Residues in Dried Kelp by Gas Chromatography (GC)

Abstract

In this study, a special method was developed for the determination of 7 kinds of polychlorinated biphenyls (PCBs) residues in dried kelp by gas chromatography (GC) with electron capture detector (ECD). The PCBs were extracted with hexane/dichloromethane (1/1, v/v) by ultrasonic extraction. Clean-up methods were used by concentrated sulphuric acid, neutral alumina oxide solid phase extraction cartridge and silica solid phase extraction cartridge. The analytical compounds were quantified by an internal standard method. Under optimal experimental conditions, good linearity was observed in the range of 5~200ng/mL, and the correlation coefficients were 0.9993~0.9998. The limit of quantification (LOQ) for target analytical compounds ranged from 6.0 to 7.5μg/kg. At the spiked levels of 10，20，50 μg/kg，the average recoveries ranged from 81.8% to 105% with the relative standard deviations 3.05%～11.2%. The result showed that the proposed method was accurate and could be used for the determination of the PCBs in dried kelp.