天然气分析 生物甲烷中的硅含量 第1部分：原子发射光谱法（AES）测定总硅

[中文适用范围]： 本文件适用于生物甲烷、沼气等气态基体中总硅含量的测量。 硅存在于气相中，主要包含在硅氧烷化合物、三甲基硅烷和三甲基硅烷醇中。 在进行取样和衍生化程序之后，在液相中测量的硅的分析形式是在微酸化介质中稳定的可溶性六氟硅酸盐阴离子。 总硅表示为分析气体体积中硅的质量。 本文件适用于硅浓度高达 5 mg/m3 的规定气态基质，通常适用于硅质量浓度为 0.1 mg/m3 至 0.5 mg/m3 的生物甲烷基质。 通过调整以确保适当的吸收效率，它可以用于更高的浓度。 根据 0.020 m3 的气体样品体积，该方法的检测限估计为 0.05 mg/m3。 气相中存在的所有化合物在吸收和衍生化温度下都是挥发性的，并且气态有机硅物质被捕获在吸收介质中并衍生成通过该方法测量的分析硅。 在微波或感应耦合等离子体中原子化/电离时使用原子发射光谱法测量稀释的衍生化介质中的硅浓度。 除非另有说明，所有体积和浓度均指标准参考条件（温度，273 K，压力，101,325 kPa）。 注：当使用适当的稀释因子时，该方法也适用于硅浓度高于 5 mg/m3 的情况。 [外文原描述]： This document is applicable to the measurement of the total silicon content in gaseous matrices such as biomethane and biogas. Silicon is present in a gas phase contained predominantly in siloxane compounds, trimethylsilane and trimethylsilanol. The analytical form of the silicon measured in liquid phase after conducted sampling and derivatization procedure is soluble hexafluorosilicate anion stable in slightly acidified media. Total silicon is expressed as a mass of silicon in the volume of the analysed gas. This document is applicable to stated gaseous matrices with silicon concentrations up to 5 mg/m 3 , and it is prevalently intended for the biomethane matrices with Si mass concentration of 0,1 mg/m 3 to 0,5 mg/m 3 . With adaptation to ensure appropriate absorption efficiency, it can be used for higher concentrations. The detection limit of the method is estimated as 0,05 mg/m 3 based on a gas sample volume of 0,020 m 3 . All compounds present in the gas phase are volatile at the absorption and derivatization temperature and gaseous organosilicon species are trapped in absorbance media and derivatized into analytical silicon that is measured by this method. The concentration of the silicon is measured in diluted derivatization media using atomic emission spectrometry upon atomisation/ionisation in microwave or inductively coupled plasma. Unless specified otherwise, all volumes and concentrations refer to standard reference conditions (temperature, 273 K, and pressure, 101,325 kPa). NOTE When using appropriate dilution factors, the method can also be applied for silicon concentrations above 5 mg/m 3 .