Extraction Of Phthalate Esters And Polychlorinated Biphenyls From Solid Samples By Combined Ultrasound And Microwave Assisted Extraction And Chromatography Determination

Both phthalate esters and polychlorinated biphenyls are typical persistent organic pollutants, and they are widely used in industry manufacturing. Due to these two persistent organic pollutants'low solubility, hydrophobic character, resistance to degradation and accumulation in organisms that has been linked to adverse health effects, phthalate esters and polychlorinated biphenyls can represent a risk to environmental and human health. To investigate the concentration levels of them in environmental samples is necessary. Phthalate esters and polychlorinated biphenyls residues in the environmental samples are often at trace level, so the analytes should be extracted and separated by the pretreatment techniques before their analysis.As a new preconcentration technique, ultrasound/microwave assisted extraction is quick, efficient, solvent-free, simple and safe. The method to determine phthalate esters in soil and sole materials and polychlorinated biphenyls in soil by chromatography after ultrasound/microwave assisted extraction has been set up. The main researches are listed as follows:1.The determination of phthalate esters in soil by GC-FID after ultrasound/ microwave assisted extraction and solid phase extraction using Florisil(?) cartridges was studied. The influence of several parameters on the extraction efficiencies such as solvent, microwave power, time of extraction had been investigated, and the optional operation conditions were obtained. When chosen 60ml n-hexane-acetone(1/1,v/v) as the extraction solvent, the average recoveries of PAEs was 92.5% after 12min extraction at 100w microwave and 50w ultrasonic treatment. The recoveries of PAEs by this method were higher than those by single open microwave extraction and ultrasonic extraction. Finally, this method was applied in the determination of PAEs in the lake sediment, the results were agreement with those by Soxhlet-GC. The detection limits of the overall method ranged between 0.05 and 0.16mg/kg, and the relative standard deviations were below 5.8%.2.A new method, ultrasound/microwave assisted extraction coupled with solid-phase extraction using Florisil(?) cartridges, was developed for the determination of phthalate esters in six sole materials by HPLC or GC-MS. After extraction and separation of phthalate esters from sole materials by soxhlet extraction, the analytes were determined by HPLC and GC/MS, respectively. The results obtained by HPLC were agreement with those by GC/MS. The extraction parameters(i.e. extractant, microwave power, extraction time) were optimized by comparing the extraction efficiencies of PAEs by ultrasound/microwave assisted extraction with those by soxhlet extraction. The optimum extraction of these compounds was carried out at an intermediate microwave power (75W) with 30ml n-hexane-acetone (1:2) mixture for 10min. Moreover, the ultrasonic power for all the experiments was fixed at 50W. The mean extraction recoveries of PAEs in the sole materials can reach 77.7%-93.3%, which can meet the requirements of quantitative determination. Finally, the optimized extraction method was compared with single microwave assisted extraction (MAE) and ultrasonic extraction (USE). It can be observed that the extraction efficiencies of PAEs obtained by ultrasound/microwave assisted extraction were significantly higher than those obtained by single MAE and USE.3.The determination of polychlorinated biphenyls in soil by GC-ECD after ultrasound/microwave assisted extraction and solid phase extraction using Florisil(?) cartridges was studied. The influence of several parameters on the extraction efficiencies such as solvent, microwave power, time of extraction had been investigated, and the optional operation conditions were obtained. When chosen 60ml n-hexane-acetone(1/1,v/v) as the extraction solvent, the average recoveries of PCBs were above 85% after 9min extraction at 100w microwave. The recoveries of PCBs by this method were higher than those obtained by single open microwave extraction and ultrasonic extraction. The detection limits of PCB-5 and PCB-11 were 0.002 and 0.005mg/kg, and the relative standard deviations were 4.5% and 5.3%, respectively. Finally, this method was applied in the determination of PCBs in the lake sediment, the results were agreement with those by Soxhlet-GC.