硅酸盐岩石中氧化亚铁量测定方法的改进

Improvement of Determination Method of Ferrous Oxide in Silicate Rock

对硅酸盐岩石中氧化亚铁量测定的国标方法进行了改进,改用聚四氟乙烯坩埚溶样,实验探讨了溶样温度及时间的选择,滴定剂的用量,防氧化措施等。实验得出,该方法不仅适用于硅酸盐岩石中氧化亚铁量的测定,也适用于土壤和水系沉积物中氧化亚铁量的测定。通过对6个不同国家标准物质的实际样品分析,方法的重复限性合格率达到97%,分析结果的准确度和精密度均满足《DZ/T0130.3—2006地质矿产实验室测试质量管理规范·第三部分:岩石矿物样品化学成分分析》要求。且方法无需在铂金坩埚进行溶样,经济便捷,且准确度高,重现性好,可用于大批量样品分析。

The national standard method for the determination of ferrous oxide in silicate rocks was improved. PTFE crucible was used to dissolve the sample instead of platinum crucible. The selection of temperature and time of sample dissolution, the amount of titrant and anti-oxidation measure were investigated by the experiments. It was found that the method was not only suitable for the determination of ferrous oxide in silicate rock, but also suitable for the determination of ferrous oxide in soil and water sediment samples. Through the analysis of the actual samples of six different national reference materials, the qualified rate of the repeatability limit of the method reached 97%, and the accuracy and precision of the analysis results met the requirements of "geological and mineral laboratory test quality management specification-Part 3: chemical composition analysis of rock and mineral samples"(DZ/T 0130.3—2006). The method is economical, convenient, accurate and reproducible, and can be used for the analysis of large quantities of samples.