GB/T 12690.6-2003
AbolishedChemical analysis methods for non-rare earth impurities of rare earth metals and their oxides--Determination of iron content--Kalium thiocyanate,1,10-phenanthroline spectrophotometric method
稀土金属及其氧化物中非稀土杂质化学分析方法 铁量的测定 硫氰酸钾、1,10-二氮杂菲分光光度法