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 °C, and 60 min for ED; and 50 μL 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 .