Ultrasound leaching - dispersive liquid-liquid microextraction based on solidification of floating organic droplet for determination of polybrominated diphenyl ethers in sediment samples by gas chromatography-tandem mass spectrometry

Abstract

Ultrasound leaching–dispersive liquid–liquid microextraction using solidification of floating organic droplet (USL–DLLME-SFO) technique is proposed for extraction and isolation of polybrominated diphenyl ethers (PBDEs) from sediment and further determination by gas chromatography–tandem mass spectrometry (GC–MS/MS). Parameters that affect the efficiency of the procedure were investigated by a full factorial (2k) screening design. Variables showing significant effects on the analytical responses were considered within a further central composite design (CCD). The optimization assays have led to following protocol: ultrasound assisted lixiviation of 1 g sediment was carried out by using 1.2 mL MeOH. Further, the analytes were isolated from 0.4 mL of the extract using the DLLME-SFO technique. The microextraction was performed using 0.1 mL MeOH, 22 mg 1-dodecanol, 1 mL NaCl solution 6.15 M and 4.4 mL ultrapure water as dispersive and extracting solvents, medium ionic strength and dispersant bulk, respectively. Under optimum conditions, the method exhibits good performance in terms of linearity and precision (RSD < 9.2%), with recoveries above 71% and limits of detection (LODs) within the range 0.5–1.8 pg g-1 dry weight (d.w.). Method validation was demonstrated through the analysis of environmental sediment samples in which PBDEs were detected and quantified. The presence of BDE-47, -100, -99 and -153 was reported within the concentration range of <LOD to 29 pg g-1 d.w. The proposed methodology constitutes a suitable approach for the analysis of PBDEs in complex solid samples requires minimum organic solvents consumption, sample manipulation, and increases sample throughput.