Determination of Polychlorinated Biphenyls in Marine Sediments by Ultrasound-Assisted Isolation and Dispersive Liquid-Liquid Microextraction and Gas Chromatography-Mass Spectrometry

A new method is reported to determine polychlorinated biphenyls (PCBs) in marine sediments using ultrasound-assisted extraction and dispersive liquid-liquid microextraction with gas chromatography-mass spectrometry. To optimize the method, acetone, acetonitrile, and methanol were characterized for extraction from the sediments. Acetone provided the highest yield. A lower-density solvent system was utilized with isooctane and acetone, and the upper solvent was characterized by gas chromatography-mass spectrometry. The optimized procedure was validated. Sediments were fortified with PCBs 28, 52, 101, 118, 138, 153, and 180 at six concentrations from 0.25 to 8.0 ng g(-1) and used to prepare matrix-matched calibration curves. Samples were analyzed using this optimized procedure. The linearity was satisfactory in all cases, with correlation coefficients from 0.9989 to 0.9995. The limits of detection and quantification were from 0.021 to 0.057 ng g(-1) and 0.069 to 0.190 ng g(-1), respectively. The recovery values at three fortified concentrations were 90.07-100.4% and the relative standard deviations were less than 7.6%. The reported extraction method uses a low-density, low-toxicity solvent; a sample syringe as the extraction device; and does not require additional purification after extraction from sediment. The protocol is sensitive, convenient, and ecofriendly and was used to determine PCBs in marines with satisfactory results.