An automatic cryotrapping and cryofocussing system for parallel ICP-MS and EI-MS detection of volatile arsenic compounds in gaseous samples
An automatic cryotrapping and cryofocussing system for parallel ICP-MS and EI-MS detection of volatile arsenic compounds in gaseous samples
复制标题
DOI：
10.1039/c2ja30251a
复制
发表时间：
2013-01
影响因子：
3.4
通讯作者：
G. Ilgen;Jen‐How Huang
中科院分区：
文献类型：
--
作者：
G. Ilgen;Jen‐How Huang
提出了一种新的 GC-ICP-MS/EI-MS 耦合方法，可以同时定量和鉴定气态样品中的挥发性金属和类金属化合物。所建议的组件使用 Windows 兼容软件完全控制，以确保精确且可重复的分析结果。冷冻捕集 (CT) 系统对于灵敏、精确地检测挥发性砷化合物至关重要。因此，重新设计了CT捕集器，并对影响CT效率的因素进行了全面优化，特别是捕集材料、捕集流量、加热速率和捕集温度。硅烷化玻璃珠（2mm）作为CT捕集器的填充材料大大提高了捕集效率。相对较高的捕获流速 (200 mL min−1) 可获得最佳回收率。需要足够的加热速率（例如 11.3 瓦 × 360 秒）来解吸砷并防止热分解。液氩被证明是最合适的冷却剂，因为它可以防止 O2 冻结和疏水阀堵塞。相比之下，冷冻聚焦（CF）对上述参数的依赖性较小。厚膜色谱法可以在室温下对不同的胂化合物进行基线分离，并消除氙的干扰。使用 CT-CF 技术分析具有更复杂结构的挥发性砷（例如三乙胂）适合定性，但由于这些化合物的稳定性较低，不适用于定量目的。 ICP-MS 检测砷化氢和甲基砷化氢的检测限和 RSD 为 0.12–0.41 pg 砷和 0.76–1.29%，明显低于以前的研究。
A new GC-ICP-MS/EI-MS coupling is presented, which enables the quantification and identification of volatile metal and metalloid compounds in gaseous samples simultaneously. The proposed assembly is fully controlled using Windows compatible software to ensure precise and reproducible analytical results. The cryotrapping (CT) system is critical for sensitive and precise detection of volatile arsenic compounds. Thus, the CT trap was newly designed and factors affecting CT efficiency were comprehensively optimized, especially the trapping materials, trapping flow rates, heating rates and trapping temperatures. Silanized glass beads (2 mm) as the packing material in the CT trap greatly increased the trapping efficiency. A relatively high trapping flow rate (200 mL min−1) gave the best recoveries. An adequate heating rate (e.g. 11.3 watt × 360 s) was required to desorb arsenic and to prevent thermal decomposition. Liquid argon was demonstrated to be the most appropriate coolant, since this prevented freezing of O2 and blockage of the trap. In comparison, cryofocusing (CF) was less dependent on aforementioned parameters. Thick film chromatography allowed baseline separation of different arsine compounds at room temperature and eliminated the interference from xenon. Analysis of volatile arsenic with more complicated structures such as triethylarsine using a CT-CF technique is suitable for qualitative but not for quantitative purposes due to lower stability of these compounds. The resulting detection limits and RSD of arsine and methyl arsines with ICP-MS detection are 0.12–0.41 pg arsenic, and 0.76–1.29%, which is remarkably lower than those in previous studies.