Determination of xenoestrogens alkylphenols in oyster and snail tissues by extractive steam distillation and gas chromatography-mass spectrometry

A simple and sensitive method is presented for the determination of two well-known xenoestrogens alkylphenols (4-tert.-octylphenol (4-t-OP) and 4-nonylphenol isomers (4-NPs)) in oysters and snails. The method involves extraction of the sample by a modified Nielson-Kryger steam distillation extraction, and the alkylphenols were then identified and quantitated by gas chromatography-mass spectrometry (GC-MS) in selected ion monitoring (SIM) mode. The quantitation limit of this method was less than 20 ng/g in 0.5 g (dry weight) of the samples. The perfect applicability of the steam distillation extraction method for 4-t-OP and 4-NPs was determined after testing it with spiked and real samples. Recovery of 4-t-OP and 4-NPs in spiked tissue samples was above 88% while relative standard deviation (RSD) ranged from 7 to 14%. 4-tert.-octylphenol and 4-nonylphenol isomers are ubiquitous in oysters and snails with the concentrations of 4-t-OP and 4-NPs ranging from 70 to 820 ng/g and from 210 to 2750 ng/g (dry weight), respectively.