Standard No.:	GB 7469-1987
English Name:	Water quality-Determination of total mercury-potassium permanganats-potassium persalfate decomposed method-Dithizonc spectrophotometric method
Chinese Name:	水质总汞的测定高锰酸钾过硫酸钾消解法双硫腙分光光度法
Chinese Classification:	Z16    Analysis methods for toxic substances in water
Professional Classification:	GB    National Standard
Issued by:	AQSIQ
Issued on:	1987-3-14
Implemented on:	1987-8-1
Status:	valid
Language:	English
File Format:	PDF
Word Count:	3000 words
Price(USD):	60.0
Delivery:	via email in 1 business day

1 Definition Total mercury: mercury concentration in unfiltered water sample determined through fierce decomposition, including inorganic, organically combined, soluble and suspended all mercury (Hg). 2 Principle Potassium permanganate and potassium persalfate are used to decompose the sample at 95℃, and all mercury contained is transformed to mercury (II). The excessive oxidizer is reduced with hydroxylamine hydrochloride, and under acidic condition, mercury ion will react with dithizone to generate orange chelate, it will be extracted with organic solvent and then the excessive dithizone is washed away with alkali solution.

Contents 1 Definition 2 Principle 3 Reagent 4 Apparatus 5 Sampling and Sample 6 Procedures 7 Result Expression Appendix A (Informative) General Explanation Additional Explanation