GB/T 4698.22-2017 Methods for chemical analysis of titanium sponge ,titanium and titanium alloys—Part 22:Determination of niobium content—5-Br-PADAP spectrophotometry and inductively coupled plasma atomic emission spectrometry (English Version)
2017GB/T 4698.22-2017 Methods for chemical analysis of titanium sponge ,titanium and titanium alloys—Part 22:Determination of niobium content—5-Br-PADAP spectrophotometry and inductively coupled plasma atomic emission spectrometry
1996GB/T 4698.22-1996 Sponge titanium, titanium and titanium alloys--Determination of niobium content--2-(5-Bromo-2-pyridylazo)-5-Diethylaminophenol spectrophotometric method