Comparing the precision of selenium isotope ratio measurements using collision cell and sector field inductively coupled plasma mass spectrometry
Comparing the precision of selenium isotope ratio measurements using collision cell and sector field inductively coupled plasma mass spectrometry
复制标题
DOI：
10.1016/j.talanta.2007.10.046
复制
发表时间：
2008-03-15
期刊：
影响因子：
6.1
通讯作者：
Hintelmann, Holger
中科院分区：
文献类型：
--
作者：
Elwaer, Nagmeddin;Hintelmann, Holger
通过测量硒同位素比值，比较了两种不同类型的电感耦合等离子体质谱（ICP-MS）仪器在解决Se同位素光谱重叠方面的性能。检查是一个四极杆为基础的，六极杆碰撞细胞CC-ICP-MS和双聚焦扇形场SF-ICP-MS。由于环境，临床和营养研究中精确和准确的同位素比值测定的重要性，进行了彻底的调查，每种技术的关键仪器参数。氢化物发生系统与SF-ICP-MS耦合，以在高质量分辨率下保持高信噪比（S/N）。然而，Se-80（+）在m/z = 80时不能与氩二聚体Ar-40（2）+完全分离，即使在高分辨率模式下。将相同的氢化物发生系统耦合到碰撞池仪器，并且发现使用具有该池的H-2和He气体的混合物，氩二聚体被显著还原。使用SF-ICP-MS仪器测定的Se同位素的较低质量偏差为2.5%/amu，而CC-ICP-MS仪器观察到的质量偏差为3.6%。在优化的实验条件下，以NIST-3149硒标准溶液为例，对两种仪器测定硒同位素比值的精密度进行了评价和比较。平均而言，在3周内的三个单独测量时段内重复测量确定的不确定度范围为0.06%至0.15%和0.09%至0.30% R.S.D.。分别使用CC-ICP-MS和SF-ICP-MS仪器测定各种同位素比。通过测量82 Se测定总Se的检测限（31），发现CC-ICP-MS和SF-ICP-MS分别为1.7和4.0 ng L-1。(C)2007 Elsevier B. V.保留所有权利。
The performance of two different types of inductively coupled plasma mass spectrometry (ICP-MS) instruments for resolving spectral overlaps on S e isotopes was compared by means of selenium isotopic ratio measurements. Examined were a quadrupole-based, hexapole collisions cell CC-ICP-MS and a double-focusing sector field SF-ICP-MS. Due to the importance of precise and accurate isotope ratio determination in environmental, clinical and nutritional studies, a thorough investigation of the critical instrumental parameters of each technique was performed. A hydride generation system was coupled with SF-ICP-MS to maintain high signal-to-noise ratios (S/N) at high mass resolution. However, Se-80(+) was not completely separated from the argon dimer Ar-40(2)+ at m/z = 80, even in high-resolution mode. The same hydride generation system was coupled to a collision cell instrument and it was found that argon dimers are significantly reduced using a mixture of H-2 and He gas with the cell. A lower mass bias of 2.5% per amu was determined for measured Se isotopes using the SF-ICP-MS instrument compared 3.6% observed for the CC-ICP-MS instrument. Under optimized conditions, the precision for Se isotope ratio measurements of both instruments was evaluated and compared measuring NIST-3149 Se standard solution. On average, the uncertainty determined by repeated measurements over the span of three individual measuring sessions in a period of 3 weeks ranged from 0.06% to 0.15% and 0.09% to 0.30% R.S.D. for the various isotope ratios using the CC-ICP-MS and SF-ICP-MS instrument, respectively. The detection limits (3l) for total Se were determined by measuring 82 Se and found to be 1.7 and 4.0 ng L-1 for the CC-ICP-MS and SF-ICP-MS, respectively. (C) 2007 Elsevier B.V. All rights reserved.