GB/T 12690.6-2017 Chemical analysis methods for non-rare earth impurity of rare earth metals and their oxides—Part 6: Determination of iron content—Kslium thiocyanate, 1,10-Phenanthroline spectrophotometric method (English Version)
2017GB/T 12690.6-2017 Chemical analysis methods for non-rare earth impurity of rare earth metals and their oxides—Part 6: Determination of iron content—Kslium thiocyanate, 1,10-Phenanthroline spectrophotometric method
2003GB/T 12690.6-2003 Chemical 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
1990GB/T 12690.6-1990 Praseodymium oxide--Determination of lanthanum oxide, cerium oxide, neodymium oxide, samarium oxide and yttrium oxide contents--Emission spectrographic method