Aromatic Sulfur Compounds Enrichment from Seawater in Crude Oil Contamination by Solid Phase Extraction

Gas chromatographic analysis of Aromatic Sulfur Compounds in distilled water and seawater samples has been performed after adsorption from 100 mL water sample onto a cartridge containing a mixture of 50 mg NH2- and 50 mg C18-bonded porous silica. The Aromatic Sulfur Compounds are desorbed with a mixture of acetone-trichloromethane (1:1), which is concentrated and analysed by gas-chromatography coupled to flame ionization or mass spectrometry detectors. The average recoveries of 80 ng mL-1 of each Aromatic Sulfur Compound from distilled water and 5.0-160 ng mL-1 from seawater samples are ≤ 93.5% with a standard deviation ≤ 2.7. The limits of detection are 0.1 and 0.08 μg mL-1 for thiophene-2-carboxaldehyde and benzothiophene, respectively, and 0.07 and 0.06 μg mL-1 for dibenzothiophene and thiantrene, respectively, in GC-FID with a relative standard deviation ≤ 8.2, whereas they are 0.08 and 0.06 μg mL-1 for thiophene-2-carboxaldehyde and benzothiophene, respectively, and 0.05 and 0.04 μg mL-1 for dibenzothiophene and thiantrene, respectively, in selected ions monitoring (SIM) with a relative standard deviation ≤ 7.8.