Enzymatic Digestion Coupled to Surfactant-Assisted Dispersive Liquid-Liquid Microextraction: A Mild Approach for Determining Polybrominated Diphenyl Ethers in Human Hair Sample

Enzymatic digestion, coupled to surfactant assisted-dispersive liquid-liquid microextraction (ED-SA-DLLME), is proposed as a mild innovative sample preparation methodology to determine polybrominated diphenyl ethers (PBDEs) in human hair samples by gas chromatography. The sodium dodecyl sulfate as a promoting agent in the ED stage also acts as a dispersive agent in DLLME, providing an advantageous synergy between sample preparation stages. Experimental variables of the ED-SA-DLLME were optimized using a multivariate method. The optimal experimental conditions were: proteinase K 0.96 U mL(-1), SDS 1% (w/v), 37 degrees C, and 60 min for ED; and 50 mu L tetrachloroethylene for SA-DLLME. The notable analytical figures of merit showed LOQ in the range of 30-430 pg g(-1), relative standard deviations <9%, and recoveries of 90-94%. The PBDEs were found in human hair samples <0.07 ng g(-1).