Single Drop Microextraction of Biphenyl and Biphenyl Oxide in Aqueous Samples by Gas Chromatography-Flame Ionization Detection

In this work, biphenyl and biphenyl oxide were extracted by direct single drop microextraction (direct-SDME) and analyzed by gas chromatography flame ionization detection. The extraction occurred by suspending a 7 μL drop of toluene (as extracting solvent) containing acetonaphton (as internal standard) from the tip of a microsyringe in direct-SDME, respectively. The effect of different parameters such as 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 detection limits (S/N = 3) of the biphenyl and biphenyl oxide were 1.80 ± 0.03 and 1.10 ± 0.02 μg·mL, respectively. Good linearity was obtained for both analytes using extraction techniques with the correlation coefficients at least 0.997 and the relative standard deviations (R.S.D.) were in the range of 1% 3%. The percent recoveries of the analytes from spiked water samples were near to 100%.