Extraction and determination of biphenyl and biphenyl oxide in water samples by using ultrasound-assisted emulsification microextraction-gas chromatography-flame ionization detection

Abstract

In this article, a fast, simple and efficient method for determination of biphenyl and biphenyl oxide in water samples was developed using an ultrasound-assisted emulsification microextraction (USAEME) method based on applying low density organic solvents. 14 μL of toluene was injected slowly into a 12 mL home-designed centrifuge glass vial containing an aqueous sample without salt addition that was located inside an ultrasonic water bath. The formed emulsion was centrifuged and 2 μL of separated toluene was injected into a gas chromatographic system equipped with a flame ionization detector (GC-FID) for analysis. Under the optimum conditions, enrichment factors (EFs) of 883 and 1066 for biphenyl and biphenyl oxide, respectively, were obtained. The method performance was studied in terms of linear dynamic range (LDRs from 0.5 μg L⁻¹ to 200 μg L⁻¹ for both analytes), linearity (r² ≥ 0.995) and precision (repeatability ≤ 8%). Also, we obtained limits of detection (LODs) of 0.1 μg L⁻¹ for biphenyl and biphenyl oxide. The applicability of the USAEME method was evaluated by the extraction and determination of biphenyl and biphenyl oxide from different water samples.