气体分析.分析偏差的调查和处理

[中文适用范围]： 本国际标准规定了使用参比气体混合物或参比分析程序检测和校正气体分析程序偏差（系统误差）以及估计校正不确定度的通用方法。 分析程序偏差（和影响参数）的主要来源是仪器漂移（时间）和基质干扰（基质成分）。 此外，偏差通常随分析物浓度而变化。 因此，本国际标准制定了以下协议： ——检测和纠正有限稳定性分析系统的漂移； ——研究和处理特定范围样品成分的稳定分析系统的偏差，这些协议旨在用于方法开发和方法验证研究，可以单独进行，也可以顺序进行。 本国际标准规定了适用于系统效应的两个选项的程序，如下：a）追踪观察到的偏差模式并纠正其影响，b）对其影响进行平均并增加不确定性，其中通常第一个选项需要较低的不确定性以付出更高的努力为代价。 为了方便用户，本国际标准中规定的方法描述了成分分析的程序，即测量气体混合物中指定分析物浓度的程序。 然而，它们同样适用于与气体分析相关的气体或气体混合物的物理化学性质的测量，并且转化到该主题领域是简单的。 [外文原描述]： ISO 15796:2005 specifies generic methods for detecting and correcting bias (systematic errors) of analytical procedures for the analysis of gases, using reference gas mixtures or reference analytical procedures, as well as for estimating the correction uncertainty. The main sources of (and parameters affecting) bias of analytical procedures are instrumental drift (time) and matrix interferences (matrix composition). Moreover, bias normally varies with analyte concentration. ISO 15796:2005 therefore establishes protocols for detecting and correcting drift for an analytical system of limited stability, and for investigating and handling bias of a stable analytical system for a specified range of sample composition. These protocols are intended to be used in method development and method validation studies, either separately or sequentially. ISO 15796:2005 specifies procedures for two options, applicable to systematic effects, as follows: 1) tracing the observed pattern of deviations and correcting for their effect, 2) averaging over their effects and increasing the uncertainty, where normally the first option entails lower uncertainty at the expense of higher effort. For the convenience of the user, the methods specified in ISO 15796:2005 are described for procedures of composition analysis, i.e. procedures for measuring the concentration of a specified analyte in a gas mixture. However, they are equally applicable to measurements of physico-chemical properties of a gas or gas mixture relevant to gas analysis, and translation into this subject field is straightforward.