Trace determination of selenium in biological samples by CH4-Ar mixed gas plasma DRC-ICP-MS
Trace determination of selenium in biological samples by CH4-Ar mixed gas plasma DRC-ICP-MS
复制标题
DOI：
10.1016/j.microc.2012.10.006
复制
发表时间：
2013-05
影响因子：
4.8
通讯作者：
Wei Guo;Shenghong Hu;Yan-Xing Wang;Luyuan Zhang;Zhaochu Hu;Jiangyi Zhang
中科院分区：
文献类型：
--
作者：
Wei Guo;Shenghong Hu;Yan-Xing Wang;Luyuan Zhang;Zhaochu Hu;Jiangyi Zhang
用电感耦合等离子体质谱法直接测定ngg-1水平的硒存在严重的光谱干扰，且硒的第一电离能较高（9.75eV），导致分析灵敏度较低。本研究建立了一种准确测定生物样品中硒的CH 4-Ar混合等离子体-DRC-MS方法。以甲烷为DRC气体，通过电荷转移反应成功地消除了40 Ar ~（2+）对80 Se同位素的干扰。用CH_4-Ar混合气体等离子体代替传统的纯Ar-ICP，使样品基体中的氧离子（~（64）Zn_（16）O ~+、~（64）Ni_（16）O ~+、~（63）Cu_（16）OH ~+）和双电荷离子（~（159）Tb ~（2+）、~（160）Dy ~（2+）、~（160）Gd ~（2+））的干扰降低到50%。同时，由于CH_4-Ar混合气体等离子体中的碳增强效应，使Se ~+的灵敏度提高了3倍。此外，为了避免79 BrH+对80 Se+的干扰，采用了一种复杂的蒸发程序来去除消化液中的Br。该方法已用于50种生物学相关样品中硒的直接测定。结果表明，大多数SRM的值与认证或推荐值吻合良好。该方法具有很大的潜力，用于测定各种生物样品中痕量或痕量水平的硒。
Direct determination of ngg−1level of selenium by ICP-MS is complicated because of the presence of serious spectral interferences, and the high first ionization energy of Se (9.75eV) also results in low analytical sensitivity. In this study, a reliable method for accurate determination of Se in biological samples using CH4-Ar mixed plasma-DRC-MS was evaluated. The predominant interfering40Ar2+(from ion source) on the most abundant80Se isotope was successfully eliminated by the charge transfer reaction using methane as DRC gas. The minor interferences of oxide or hydroxides ions (64Zn16O+,64Ni16O+and63Cu16OH+) and double charged ions (159Tb2+,160,161Dy2+and160Gd2+) originating from sample matrix were decreased down to 50% using CH4-Ar mixed gas plasma instead of the conversional pure Ar-ICP. Meanwhile, the poor sensitivity of Se+was improved by a factor of 3 due to the carbon-enhancement effect in CH4-Ar mixed gas plasma. In addition, to avoid the interference79BrH+on80Se+, an elaborate evaporation procedure was used to remove the Br from the digestion solution. The proposed method was applied to direct determination of Se in fifty biologically related SRMs. Our results showed that the values of most SRMs were found to agree well with the certified or recommended values. This method has great potential for the determination of trace or trace level of Se in various biological samples.