Evaluation of expanded graphite as on-line solid-phase extraction sorbent for high performance liquid chromatographic determination of trace levels of DDTs in water samples

详细信息    查看全文

• 作者：You-Ya Zhou ; Shan-Wei Wang ; Ki-Nam Kim ; Ji-Hui Li and Xiu-Ping Yan
• 关键词：Solid-phase extraction ; High performance liquid chromatography ; Expanded graphite ; DDTs
• 刊名：Talanta
• 出版年：2006
• 出版时间：15 June 2006
• 年：2006
• 卷：69
• 期：4
• 页码：970-975
• 全文大小：196 K

文摘

Dichlorodiphenyltrichloroethane (DDT) and its metabolites are a typical kind of persistent organic pollutants (POPs). Development of a simple, cost-effective and sensitive methodology to monitor DDTs concentrations in water environment is of particular significance for understanding the fate and behavior of these pollutants. In this paper, a method on the basis of solid-phase extraction (SPE) using expanded graphite (EG) as sorbent coupled on-line with high performance liquid chromatography (HPLC) was developed for the determination of trace levels of p,p′-DDD (2,2-bis(4-chlorophenyl)-1,1-dichloroethane), p,p′-DDT, o,p′-DDT and p,p′-DDE (2,2-bis(4-chlorophenyl)-1,1-dichloroethene) in water. The analytes in water were preconcentrated onto the SPE column packed with expanded graphite, and subsequently eluted with methanol–water (90:10) mixed solvent. HPLC with a photodiode array detector was used for their separation and detection. The developed on-line solid-phase extraction protocol for HPLC permits the current HPLC separation and the next preconcentration proceeded in parallel, and thus allows one determination within 8 min. The precision (R.S.D.) for 10 replicate injections of a mixture of 1 μg l⁻¹ of each analyte was 3.2–6.2 % for the peak area measurement. The detection limits (S/N = 3) for preconcentrating 50 ml of sample solution ranged from 10 to 25 ng l⁻¹ at a sample throughput of 7.5 samples h⁻¹. The enhancement factors were about 700. The method was applied to the determination of trace p,p′-DDD, p,p′-DDT, o,p′-DDT and p,p′-DDE in local lake, river and tap water samples.