Simple approach based on dispersive liquid-liquid microextraction technique for determination of polibrominated flame retardants in water samples by GC-MS/MS

FONTANA, A.; WUILLOUD, R.; ALTAMIRANO, J.

Santa Fe

Workshop; 2nd Latin American Pesticide Residue Workshop. Food and Environment; 2009

Universidad Nacional del Litoral, Facultad de Ingeniería Química- Laboratorio Central

Polybrominated diphenyl ethers (PBDEs) are flame retardants used in a variety of consumer products including plastics, foams, textiles and electronic equipment. PBDEs are persistent environmental contaminants that bioaccumulate into the highest levels of the food chain. The analysis of PBDEs in water samples is of particular interest; however their low concentrations demands the use of pre-concentration techniques prior their determination. Therefore, it is necessary to count on highly efficient and reliable pre-concentration techniques for their determination by GC. A DLLME technique for extraction and pre-concentration of PBDEs in waters prior gas chromatography-mass spectrometry (GC-MS/MS) was developed and validate. Under optimum conditions, extraction efficiency >99% was achieved. The enrichment factors (EF) were higher than 583. The LODs of the analytes were ranged from 0.2 to 0.4 ng L-1 with RSDs values between 9.4 to 12.9%. A satisfactory linearity was observed in the range of 2-1000 ng L-1 with r² higher than 0.9991. The analytical methodology was validated in real water samples at two different concentration levels (10 and 50 ng L-1) and analyzed by DLLME-GC-MS/MS. This study led to satisfactory robustness with recoveries higher than 95 %. The PBDEs contents in the analyzed samples were below the detection limit of the proposed methodology. Under optimized working conditions, high EF were obtained for the target analytes allowing to reach detection limits in the order of picogram per liter with an acceptable precision. The method was successfully applied to determine PBDEs in real water samples, showing good recoveries and no matrix effect. Additionally, it is important to point out that DLLME is a low organic solvent consuming extraction technique, which turns it into a low cost and environmentally friendly technique.