Optimization of selective pressurized liquid extraction for extraction and in-cell clean-up of PCDD/Fs in soils and sediments

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• 作者：Lan Do ; ^{lan.do@chem.umu.se} ; Staffan Lundstedt ; Peter Haglund
• 关键词：Selective pressurized liquid extraction (SPLE) ; In-cell clean-up ; Experimental design ; PCDD/Fs ; GC/HRMS ; Soils and sediments
• 刊名：Chemosphere
• 出版年：2013
• 出版时间：March, 2013
• 年：2013
• 卷：90
• 期：9
• 页码：2414-2419
• 全文大小：464 K

文摘

This paper describes the development of methods for selective extraction of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) from soils and sediments, using pressurized liquid extraction with in-cell clean-up (SPLE). Two binary solvent mixtures, viz. dichloromethane/n-heptane (DCM/Hp), and diethylether/n-heptane (DEE/Hp), were evaluated. The SPLE extraction conditions were optimized using central composite face (CCF) design. Three factors were investigated: extraction temperature (60-160 ¡ãC), number of extraction cycles (1-3) and time per cycle (2-18 min). The results showed that DCM/Hp (1/1, v/v) and DEE/Hp (1/2, v/v) were the best extraction solvent compositions and that the extraction temperature was a critical factor that needed careful optimization to achieve high extraction efficiency without co-extraction of sulfuric acid. Under the optimal conditions, the SPLE methods provided results with good accuracy and precision. For the sandy soil certified reference material (CRM-529) the quantification results ended up in the range 82-110 % as compared to the concentrations obtained by a reference method based on Soxhlet extraction and external column clean-up. Furthermore, for a clay soil (CRM-530) and a sediment reference material (WMS-01), the accuracy (trueness) of the TEQ values were +11 % (DCM/Hp) and +8 % (DEE/Hp) for CRM-530, +8 % and ?7 % for WMS-01, respectively. The individual congener concentrations also agreed well with the certified values. These findings show that SPLE is a promising method for combined extraction and clean-up of PCDD/Fs in soil/sediment samples.