Standard No.:	GB 3143-1982
Chinese Name:	液体化学产品颜色测定法(Hazen单位-铂-钴色号)
English Name:	Color determination method of liquid chemicals(Hazen unit;Platinum-cobalt scale)
Professional Classification:	G04 Basic standards and general methods
Professional Classification:	GB National Standard
ICS Classification:	71.040.40 Chemical analysis
Issued by:
Issued on:	1982-07-02
Implemented on:	1983-03-01
Status:	VALID
Language:	English
File Format:	PDF
Word Count:	1500 words
Price(USD):	45 (USD)
Delivery:	via email in 1-3 business day

1 Method summary

The color of the sample is visually compared with that of the standard platinum-cobalt colorimetric solution, and the result is expressed in Hazen (platinum-cobalt) color unit. Hazen (platinum-cobalt) color unit is the color of solution containing 1mg of platinum (in chloroplatinic acid) and 2mg of cobalt chloride hexahydrate per liter.

2 Apparatus

2.1 Type 72 spectrophotometer or similar spectrophotometer.

2.2 Nessler tube: 50mL or 100mL with scale mark at 100mm above the bottom.

2.3 Colorimetric tube rack: generally, the bottom of the colorimetric tube rack is lined with a white base plate, and a reflector can be installed at the bottom to improve the color observation effect.

3 Reagent

3.1 Cobalt chloride hexahydrate (CoCl2?6H2O): analytical reagent.

3.2 Hydrochloric acid: analytical reagent, complying with GB 622 Hydrochloric acid.

3.3 Chloroplatinic acid (H2PtCl6):

Preparation method of chloroplatinic acid: dissolve 1.00g of platinum in sufficient aqua regia by heating in a boiling water bath in a glass dish or a porcelain dish; after the platinum is dissolved, evaporate the solution to dryness; add 4mL of hydrochloric acid solution and evaporate the solution to dryness; repeat the operation for more than two times and 2.10g of chloroplatinic acid can be obtained.

3.4 Potassium chloroplatinate (K2PtCl6): analytical reagent.