Determination of polybrominated biphenyls in environmental water samples by ultrasound-assisted dispersive liquid-liquid microextraction followed by high-performance liquid chromatography

Dispersive liquid-liquid microextraction (DLLME) is an extraordinarily fast and effective sample preparation procedure. In this work, a simple, rapid, and sensitive method using ultrasound-assisted dispersive liquid-liquid microextraction (UA-DLLME) combined with high-performance liquid chromatography (HPLC) has been developed for rapid determination polybrominated biphenyls (PBBs) in real water samples. The key parameters affecting the extraction efficiency including the extractant, dispersant, the volumes of extractant and dispersant, and ultrasound time were optimized, and further validated by orthogonal array design (OAD), a L-16 (4(4)) matrix was applied for the identification of optimized extraction parameters, and the optimized method was successfully applied to the analysis of environmental water sample. The results showed good linearity (correlation coefficients > 0.9942), low limits of detection (0.11-0.12 mu g L-1), wide linear ranges (0.5-1000 mu g L-1), and acceptable repeatability (relative standard deviation, RSD < 5.2% for intra-day, RSD < 6.3% for inter-day). Moreover, the method is further applied to the analysis of four PBBs in real samples with good recoveries (75.8%-105%) and satisfactory precisions (RSD < 6.5%). The optimized conditions provided enrichment factors (EFs) for PBBs of 211-245.