Gas Chromatographic Determination of Benzene Homologues in Water with Head-Space Single-Drop Microextraction

Benzene homologues in water were separated and enriched by head-space single-drop microextraction and determined by gas chromatography.Effects of different kinds of extraction solvents and extraction condition on the testing results were studied thoroughly.Detection limits (S/N=3) of the method were found to be 0.05 μg·L-1 for benzene and toluene,and 0.03 μg·L-1 for p-xylene.Linear relationships between peak area and concentration of the homologues within 10 μg·L-1 were obtained for all the 3 compounds.Correlation coefficients of 0.999 2,0.998 5 and 0.997 2 were found for the 3 compounds respectively.Recovery was tested by adding 2 μg·L-1 of the standard solutions to a sample of waste water,results obtained were 98.3% for benzene,101.9% for toluene and 97.3% for p-xylene.