Determination of biphenyl and biphenyl oxide in aqueous samples by headspace single drop microextraction coupled to gas chromatography

in this work, biphenyl and biphenyl oxide were extracted by headspace single drop microextraction (hs-sdme) and analyzed by gas chromatography-flame ionization detection (gc-fid). the extraction occurred from the tip of a microsyringe by suspending a 3.5 μl drop of toluene, as extracting solvent, containing acetonaphton, as internal standard. the effect of different parameters such as the nature of extraction solvent, microdrop and sample temperatures, stirring rate, microdrop and sample volumes, ionic strength and extracting time on the extraction efficiency of the analytes were investigated and optimized. under optimized conditions the limits of detection (s/n = 3) of biphenyl and biphenyl oxide were 0.40 ± 0.03 and 0.30 ± 0.06 μg ml？1, respectively. good linearities were obtained for both analytes with the correlation coefficients higher than 0.997 and the relative standard deviations (r.s.d.) were in the range of 1-3%. the recoveries of analytes from spiked water samples were near to 100%.