GB/T 12690.4-2003 Chemical analysis methods for non-rare earth impurities of rare earth metals and their oxides—Determination of oxygen and nitrogen content—Impulse-infrared and impulse-thermal conductance absorption method

GB/T 12690.5-2003 Chemical analysis methods for non-rare earth impurities of rare earth metals and their oxides—Determination of Al、Cr、Mn、Fe、Co、Ni、Cu、Zn、Pb content by inductively coupled plasma atomic emission spectrographic method and Determination of Co、Mn、Pb、Ni、Cu、Zn、Al、Cr content by inductively coupled plasma mass spectrum method GB/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 GB/T 12690.7-2003 Chemical analysis methods for non-rare earth impurities of rare earth metals and their oxides Determination of silicon content Molybdenum blue spectrophotometric method GB/T 12690.8-2003 Chemical analysis methods for non-rare earth impurities of rare earth metals and their oxides—Determination of sodium content—Flame atomic absorption spectrometric method GB/T 12690.9-2003 Chemical analysis methods for non-rare earth impurities of rare earth metals and their oxides Determination of chlorine content Silver nitrate turbidimetric method GB/T 12690.10-2003 Chemical analysis methods for non-rare earth impurities of rare earth metals and their oxides Determination of phosphorus content by molybdenum blue spectrophotometric method GB/T 12690.11-2003 Chemical analysis methods for non-rare earth impurities of rare earth metals and their oxides—Determination of magnesium content—Flame atomic absorption spectrometric method GB/T 12690.12-2003 Chemical analysis methods for non-rare earth impurities of rare earth metals and their oxides Determination of thorium content Arsenazo III spectrophotometric method and Inductively coupled plasma mass spectrum method GB/T 12690.13-2003 Chemical analysis methods for non-rare earth impurities of rare earth metals and their oxides—Determination of molybdenum and tungsten content—Inductively coupled plasma atomic emission spectrographic method and Inductively coupled plasma mass spectrum method and inductively coupled plasma mass spectrum method

GB 12690.12-1990 GB 15917.4-1995

GB/T 12690.4-2021 Chemical analysis methods for non-rare earth impurities of rare earth metals and their oxides—Part 4:Determination of oxygen and nitrogen contents—Impulse-infrared absorption and impulse-thermal conductivity method