Determination of Polybrominated Diphenyl Ethers in Water and Soil Samples by Cloud Point Extraction- Ultrasound-Assisted Back-Extraction-Gas Chromatography–Mass Spectrometry

FONTANA, ARIEL R.; SILVA, MARIA F.; MARTINEZ, LUIS D.; WUILLOUD, RODOLFO G.; ALTAMIRANO, JORGELINA C.

JOURNAL OF CHROMATOGRAPHY - A

Elsevier

Lugar: Amsterdam; Año: 2009 p. 4339 - 4346

0021-9673

A novel and efficient analytical methodology is proposed for extracting and preconcentrating polybrominated diphenyl ethers (PBDEs) from water samples prior gas chromatography–mass spectrometry (GC–MS) analysis. It is based on the induction of micellar organized medium by using a non-ionic surfactant (Triton X-114) to extract the target PBDEs. To enable coupling the efficient extracting technique with GC analysis, ultrasound-assisted back-extraction (UABE) into an organic solvent was required. Several factors, including surfactant type and concentration, equilibration temperature and time, ionic strength, pH and buffers nature and concentration were studied and optimized over the extraction efficiency of the proposed technique. Under optimal experimental conditions, the target analytes were quantitatively extracted achieving an enrichment factor of 250 when 10 mL aliquot of ultrapure water spiked with PBDE-standard mixture (10 pg mL-1 each PBDE) was extracted. Detection limits (LODs) calculated as three times the signal-to-noise ratio (S/N), ranged from 1.0 to 2 pg mL-1 and the RSDs were ≤ 8.3 % (n = 5) when 10 pg mL-1 PBDE-standard mixture was analyzed. The coefficients of estimation of the calibration curves obtained following the proposed methodology were ≥0.9987 and linear range of all PBDEs was 4– 150 pg mL-1. The proposed methodology was applied for the analysis of PBDEs: 2,2’,4,4’-tetraBDE (BDE-47), 2,2’,4,4,5-pentaBDE (BDE-99), 2,2’,4,4,6-pentaBDE (BDE-100) and 2,2,4,4’,5,5’-hexaBDE (BDE-153) in water samples including drinking, lake and river waters. Although significant quantities of PBDEs were not found in the analyzed samples, the proposed methodology was validated by performing a recovery study spiking the samples at two different concentration levels of PBDEs (10 and 50 pg mL-1). Recoveries values in the range of 96-106% were obtained showing satisfactory robustness of the method for analyzing PBDEs in water samples.