Research Center for Chemistry-Indonesian Institute of Sciences (RCChem-LIPI) has successfully organized proficiency testing (PT) for the determination of benzoic acid, methyl paraben, and n-butyl paraben in sweet soy sauce. This is the first PT in Indonesia that uses reference values derived from a primary method gas chromatography–isotope dilution mass spectrometry method. Twenty participants from four economies registered in this PT. This paper presents the procedures in the preparation of the PT samples, the homogeneity and stability checks, as well as in the determination of the assigned values. The test samples were a candidate certified reference material prepared in accordance with ISO 17034 and ISO Guide 35. The performance evaluation of participants’ results was conducted in accordance with ISO 13528 by using the PROLab™ software. This paper also discusses the approaches taken in the calculation of the performance’s scores which were set according to the criterion required in homogeneity check, stability check, and limit of uncertainty.

中文翻译：

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首次使用同位素稀释质谱法参考值对甜酱油中的苯甲酸、对羟基苯甲酸甲酯和对羟基苯甲酸正丁酯进行印度尼西亚能力测试

印度尼西亚科学院化学研究中心 (RCChem-LIPI) 成功组织了能力测试 (PT)，用于测定甜酱油中的苯甲酸、对羟基苯甲酸甲酯和对羟基苯甲酸正丁酯。这是印度尼西亚第一个使用源自主要方法气相色谱-同位素稀释质谱法的参考值的 PT。来自四个经济体的 20 名参与者在该 PT 中注册。本文介绍了制备 PT 样品、均匀性和稳定性检查以及确定指定值的程序。测试样品是根据 ISO 17034 和 ISO 指南 35 制备的候选认证参考材料。参与者结果的性能评估是根据 ISO 13528 使用 PROLab™ 软件进行的。