紫外荧光法测定天然气中总硫含量的精密度研究

为了对紫外荧光法测定天然气中总硫含量的精密度要求作一个独立研究，在8家实验室用不同的紫外荧光总硫含量分析仪分别对同一批次22个样品进行了重复测试，根据ISO 4259:2006《石油产品 试验方法精密度数据的确定和应用》对数据进行了处理，得到了紫外荧光法测定总硫含量的精密度要求。研究结果表明：在重复性/再现性条件下，在95%的置信区间里，获得的两次独立测试结果的差值不超过相应浓度范围内的重复性限/再现性限。该研究成果为紫外荧光法总硫含量测试的结果判定提供了参考，也为相应的ISO标准“总硫/紫外荧光法”的编制提供了直接的技术支撑。与现行的GB/T 11060.8—2012《天然气 含硫化合物的测定 第8部分：用紫外荧光光度法测定总硫含量》中精密度要求相比，该研究成果总体上更为优越，并建议开展上述国家标准的修订研究工作。

Detection precision of the total sulfur contents in natural gas by the ultraviolet fluorescence method

For the sake of independent study on the requirement of the detection precision of the total sulfur contents in natural gas by the ultraviolet fluorescence method, 22 samples of the same batch were tested repeatedly in eight laboratories by using different ultraviolet fluorescence total sulfur analyzers. Then, the experimental data were processed according to The Code of Petroleum Products-Determination and Application of Precision Data in Relation to Test Methods (ISO 4259:2006). And accordingly, the requirement of the detection precision of the total sulfur contents by the ultraviolet fluorescence method was determined. It is indicated that under the condition of repeatability/reproducibility, the difference between two independent test results should not exceed the limit of repeatability/reproducibility in the corresponding concentration range at the 95% confidence interval. This research result provides a reference for the result determination of total sulfur content tests by the ultraviolet fluorescence method, as well as a direct technical support for the preparation of the ISO standard "Total Sulfur/Ultraviolet Fluorescence Method". Compared with the precision requirement of the current standard of Natural Gas-Determination of Sulfur Compound-Part 8: Determination of Total Sulfur Content by Ultraviolet Fluorescence Method (GB/T 11060.8-2012), this research result is generally superior so as to be recommended to revise the above-mentioned national standards.