电子级氮气中超痕量杂质的质谱分析方法及测量不确定度评估

发布时间：2018-07-01 12:35

本文选题：电子级氮气 + 纯化　；参考：《质谱学报》2017年05期

【摘要】：采用大气压电离质谱(APIMS)技术及标准添加法建立了一种电子级氮气中超痕量杂质的分析方法。以高效纯化后氮气中的5种杂质(CO、CH_4、H_2、O_2和CO_2)作为检测对象,以动态稀释后的标准气体作为参考进行回归分析,标准气体依据ISO 6142及ISO导则34规定的重量法在实验室制备,同时采用蒙特卡洛(MCM)法及《不确定度表示指南》描述的GUM法对本方法的不确定度进行评定。结果表明:在0~1nmol/mol范围内,5种杂质的校准曲线呈现出良好的线性关系,线性相关系数R~2均大于0.998;方法的灵敏度高,检出限可达几至几十pmol/mol水平,扩展不确定度为37%(k=2),通过与文献中报道的数据相比,CH4和CO的检出限分别改善了1个和2个数量级,H_2、O_2、CO_2则与文献的报道值基本一致。本方法能够满足对相关电子气体中杂质的分析要求,并可为量值溯源提供参考依据。
[Abstract]:An analytical method for ultratrace impurities in electron-grade nitrogen was established by means of atmospheric pressure ionization mass spectrometry (APIMS) and standard addition method. Five kinds of impurities (COHCH4H2OV2 and COS2) in highly purified nitrogen gas were used as the detection objects, and the dynamically diluted standard gas was used as the reference for regression analysis. The standard gas was prepared in the laboratory according to the gravimetric method stipulated in ISO 6142 and ISO guideline 34. At the same time, the uncertainty of this method is evaluated by the Monte Carlo (MCM) method and the GUM method described in the Guide to the expression of uncertainty. The results show that the calibration curves of five impurities in the 0~1nmol/mol range show a good linear relationship, the linear correlation coefficient R ~ (2) is greater than 0.998, the sensitivity of the method is high, and the detection limit can reach several to dozens of pmol/mol levels. The extended uncertainty is 37% (KG 2). Compared with the reported data, the detection limits of CH4 and CO are improved by 1 and 2 orders of magnitude respectively. This method can meet the requirements of the analysis of impurities in the related electronic gases and can provide reference for traceability.
【作者单位】：中国计量科学研究院;
【基金】：国家科技支撑计划(2013BAK10B03) 国家自然科学基金(41275136)资助
【分类号】：O657.63

【相似文献】