Determination of mercury in biological samples by cold vapor atomic absorption spectrometry following cloud point extraction with salt-induced phase separation

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• 作者：Ingrid M. Dittert ; Tatiane A. Maranhã ; o ; Daniel L.G. Borges ; Mariana A. Vieira ; Bernhard Welz ; Adilson J. Curtius
• 关键词：Cloud point extraction ; Cold vapor atomic absorption spectrometry ; Mercury ; Biological samples ; O ; O-diethyl dithiophosphate ; Triton X-114
• 刊名：Talanta
• 出版年：2007
• 期刊代码：106_00399140
• 类别：ch
• 出版时间：31 July 2007
• 卷：72
• 期：5
• 页码：1786-1790
• 文件大小：321 K

摘要

Method development for the pre-concentration of mercury in human hair, dogfish liver and dogfish muscle samples using cloud-point extraction and cold vapor atomic absorption spectrometry is demonstrated. Before the extraction, the samples were submitted to microwave-assisted digestion in a mixture of H₂O₂ and HNO₃. Cloud point extraction was carried out using 0.5%(m/v) ammonium O,O-diethyldithiophosphate (DDTP) as the chelating agent and 0.3%(m/v) Triton X-114 as the non-ionic surfactant. Phase separation was induced after the addition of Na₂SO₄ to a final concentration of 0.2 mol L⁻¹. Aliquots of the final extract were transferred to PTFE tubes and NaBH₄ and HCl were added. The mercury vapor was driven to a non-heated quartz tube for measuring the absorbance. The results obtained with salt-induced phase separation were in good agreement with the certified values at a 95%confidence level. An enrichment factor of 10 allowed a detection limit of 0.4 ng g⁻¹ to be obtained, which demonstrates the high sensitivity of the proposed procedure for the determination of mercury at trace levels.