Canepari Silvia, Cardarelli Enrico, Ghighi Silvano, Scimonelli Luigia
Dipartimento di Chimica, Università di Roma "LaSapienza", P.le Aldo Moro, 5 Rome, Italy.
Talanta. 2005 Jun 15;66(5):1122-30. doi: 10.1016/j.talanta.2005.01.014.
In this paper we investigate alternatives to mechanical stirring for the extraction of the mobile fraction of metals from sediment, and analyze whether these techniques can reduce extraction time and improve reproducibility. We compare the quantities of metal extracted from BCR601 and BCR701 certified sediments using ultrasound bath, microwave-assisted extraction and the first step in the certified BCR sequential extraction procedure. Some environmentally important not-certified metals such as As, Mn, Co, Fe and Al have been included in this study. In the case of microwave-assisted extraction, we compare tests in which samples are exposed to constant, low power irradiation with tests using pulsed high power. In the tests using the ultrasound bath, less metal was extracted than with the other extractive techniques and standard deviations were comparable to those obtained with the BCR procedure; in assays using microwaves at constant power, extraction efficiencies were different for different metals and for different reference materials and, in some cases, standard deviations were higher than those for the reference method. In contrast, tests with microwaves and constant temperature produced encouraging results: R.S.D.s lay in the 2-4% range, both for certified and not-certified metals; these values are very low compared to those for the reference method. Extraction efficiencies for certified metals were close to 100% for Cd, Zn, Cu and Ni and around 80% for Pb and Cr.
在本文中，我们研究了替代机械搅拌从沉积物中提取金属可移动部分的方法，并分析了这些技术是否能够缩短提取时间并提高重现性。我们比较了使用超声浴、微波辅助萃取以及BCR认证顺序萃取程序第一步从BCR601和BCR701认证沉积物中提取的金属量。本研究还纳入了一些对环境有重要意义的非认证金属，如砷、锰、钴、铁和铝。对于微波辅助萃取，我们比较了样品暴露于恒定低功率辐射的试验与使用脉冲高功率的试验。在使用超声浴的试验中，提取的金属比其他萃取技术少，且标准偏差与BCR程序获得的相当；在使用恒定功率微波的分析中，不同金属和不同参考物质的萃取效率不同，在某些情况下，标准偏差高于参考方法。相比之下，恒温微波试验产生了令人鼓舞的结果：对于认证和非认证金属，相对标准偏差（R.S.D.）都在2-4%的范围内；与参考方法相比，这些值非常低。对于认证金属，镉、锌、铜和镍的萃取效率接近100%，铅和铬的萃取效率约为80%。
