Determination of petroleum contamination in shellfish using solid phase micro-extraction with gas chromatography-mass spectrometry

Headspace solid phase micro-extraction (HS-SPME) has been applied as a sampling technique for the determination of petroleum contamination in shellfish using capillary gas chromatography-mass spectrometry (GC-MS). A poly(dimethylsiloxane) fused silica fibre (100 microm thickness) was found to be satisfactory for the extraction of a range of aliphatic hydrocarbons (HCs) from homogenised shellfish tissues. The SPME conditions, including temperature, salt content, extraction time and desorption temperature, were optimised for a range of aliphatic HCs (C9-C20). A methyl silicone column GC (12 m x 0.20 mm, 0.33 microm layer thickness) was used with a temperature programme from 40 to 260 degrees C and the HCs were determined within a mass range of m/ z=50-550 in electron impact mode. Calibration range was from 10 to 5000 ng/g with linear correlation coefficients ( r(2)) of 0.982 for nonane to 0.997 for octadecane. Detection limits for aliphatic HCs, spiked into shellfish (mussel) tissues, varied from 3.6 ng/g (tetradecane) to 51 ng/g (eicosane) and relative standard deviation (% RSD) values ranged from 1.4% (hexadecane) to 24.3%(eicosane).