GB/T 7698-2014 in English

《GB/T 7698-2014工业用氢氧化钠 碳酸盐含量的测定 滴定法》由TC63（全国化学标准化技术委员会）归口，TC63SC6（全国化学标准化技术委员会氯碱分会）执行，主管部门为中国石油和化学工业联合会。
本标准规定了工业用氢氧化钠中碳酸盐含量测定的方法。
本标准适用于碳酸盐(以Na2CO3 计)的质量分数大于或等于0.02%的产品。
通过预试验,样品分为三类:
a) 不含硫化物和氯酸盐的样品。
b) 含硫化物的样品。本标准适用于硫化物(以Na2S计)的质量分数小于0.1%的产品。
c) 含氯酸盐的样品。本标准适用于氯酸盐(以NaClO3 计)的质量分数小于0.2%的产品。
b)和c)类样品因含有干扰成分,对分析步骤做适当的修改(见第10章)。

Scope

This standard specifies the method for the determination of carbonate content in sodium hydroxide for industrial use. This standard is applicable to products whose mass fraction of carbonate (calculated as Na₂CO₃) is greater than or equal to 0.02%. Through the pre-test, the samples are divided into three categories: a) Samples without sulfide and chlorate. b) Samples containing sulfides. This standard applies to products with a mass fraction of sulfide (calculated as Na₂S) less than 0.1%. c) Samples containing chlorate. This standard applies to products with a mass fraction of chlorate (calculated as NaClO₃) less than 0.2%. Due to the presence of interfering components in samples of types b) and c), make appropriate modifications to the analysis steps (see Chapter 10).