Arslan Z, Ertas N, Tyson J F, Uden P C, Denoyer E R
Department of Chemistry, University of Massachusetts, Amherst 01003-4510, USA.
Fresenius J Anal Chem. 2000 Feb;366(3):273-82. doi: 10.1007/s002160050053.
A method has been developed for the determination of 23 elements in marine plankton in which inductively coupled plasma (ICP) source mass spectrometry (MS) was used to quantify the elements in the solution after digestion in a mixture of hydrofluoric and nitric acids in sealed PTFE vessels in a microwave field. The procedure was validated by the analysis of a standard reference soil (SRM 2709 San Joaquin Soil) and a standard reference fresh water plankton (CRM 414). The method was applied to the analysis of several marine plankton samples grown under controlled conditions including several whose growth media had been enriched with selenium. Matrix induced signal suppressions and instrumental drift were corrected by internal standardization. The suitabilities of germanium, indium, rhodium, scandium and yttrium as internal standard elements were evaluated. Neither scandium nor yttrium could be used due to the presence of these elements in the samples, germanium was used for the determination of As, Co, Cu, Fe, Ni, Se, Si and Zn, indium was used for Al, Ba, Ca, Eu, Sr, and Tl, and rhodium was used for Cd, Cr, Hg, Mg, Pb, Sb, Sn, and V. For Al, Ca, Cr, Cu, Fe, Mg, Mn, Ni, Si, Sr, V, and Zn internal standardization did not completely compensate for the suppressive effect of the heavier elements and the solutions were diluted. However, for As, Ba, Cd, Co, Eu, Hg, Pb, Sb, Se, Sn and T1, it was possible to obtain accurate results despite the 35-40% suppression in the signals. Isobaric overlap was only a problem in the cases of 42Ca and 78Se; 44Ca and 77Se, respectively, were used. Memory effects were only observed with Hg for which a nitric acid-sodium chloride solution was the most effective wash-out solution. The marine plankton samples were able to tolerate a higher concentration of Hg as the selenium concentration increased.
已开发出一种测定海洋浮游生物中23种元素的方法，该方法采用电感耦合等离子体（ICP）源质谱（MS）对在微波场中于密封聚四氟乙烯容器内用氢氟酸和硝酸混合液消解后的溶液中的元素进行定量分析。通过分析标准参考土壤（SRM 2709圣华金土壤）和标准参考淡水浮游生物（CRM 414）对该程序进行了验证。该方法应用于分析在受控条件下生长的几种海洋浮游生物样品，包括几种生长培养基中添加了硒的样品。通过内标法校正了基体诱导的信号抑制和仪器漂移。评估了锗、铟、铑、钪和钇作为内标元素的适用性。由于样品中存在这些元素，钪和钇均不能使用，锗用于测定砷、钴、铜、铁、镍、硒、硅和锌，铟用于测定铝、钡、钙、铕、锶和铊，铑用于测定镉、铬、汞、镁、铅、锑、锡和钒。对于铝、钙、铬、铜、铁、镁、锰、镍、硅、锶、钒和锌，内标法并未完全补偿较重元素的抑制作用，因此对溶液进行了稀释。然而，对于砷、钡、镉、钴、铕、汞、铅、锑、硒、锡和铊，尽管信号有35 - 40%的抑制，仍有可能获得准确结果。同量异位素重叠仅在42Ca和78Se、44Ca和分别77Se的情况下是个问题，分别使用了44Ca和77Se。仅在汞的情况下观察到记忆效应，对于汞，硝酸 - 氯化钠溶液是最有效的洗脱溶液。随着硒浓度的增加，海洋浮游生物样品能够耐受更高浓度的汞。
