Standard No.:	GB 223.41-1985
Chinese Name:	钢铁及合金化学分析方法 离子交换分离-连苯三酚光度法测定钽量
English Name:	Methods for chemical analysis of iron,steel and alloy; The anion-exchange separation-pyrogallol photometric method for the determination of tantalum content
Professional Classification:	H11 Steel and iron alloy analysis method
Professional Classification:	GB National Standard
ICS Classification:	77.080
Issued by:
Issued on:	1985-07-18
Implemented on:	1986-06-01
Status:	VALID
Replace:	YB35(14)-1978
Language:	English
File Format:	PDF
Word Count:	2000 words
Price(USD):	60 (USD)
Delivery:	via email in 1-3 business day

1 Principle

Tantalum and pyrogallol generate yellow complex compound in acid solution, which can be interfered by iron, titanium, niobium, molybdenum, wolfram, etc. which can be separated from tantalum with anion-exchange separation method.
Concentration and absorbance are proportionate when the tantalum content in 50ml solution is 50~800μg.

2 Reagents

2.1 Potassium pyrosulfate (solid), crushed into 3~4 mm pieces.
2.2 Hydrochloric acid (proportion: 1.19).
2.3 Hydrochloric acid (1+11).
2.4 Nitric acid (proportion 1.42).
2.5 Hydrofluoric acid (proportion 1.15).