Standard No.:	GB 7471-1987
Chinese Name:	水质 镉的测定 双硫腙分光光度法
English Name:	Water quality; Determination of cadmium; Spectrophotometric method with dithizone
Professional Classification:	Z16 Analysis methods for toxic substances in water
Professional Classification:	GB National Standard
Issued by:
Issued on:	1987-03-06
Implemented on:	1987-08-01
Status:	VALID
Target Language:	English
File Format:	PDF
Word Count:	3000 words
Translation Price:	90 (USD)
Delivery:	via email in 1-3 business day

1 Application Scope

1.1 Determination substance: this standard specifies determination of cadmium in water and waste water by spectrophotometric method with dithizone.
1.2 Sample type: this standard is applicable to determination of trace cadmium in natural water and waste water.
Relevant interference problem is detailed in Appendix A.
1.3 Scope: this method is applicable to determination of cadmium with the concentration range of 1~50μg/L; when concentration of cadmium is greater than 50μg/L, the sample is properly diluted before determination.
1.4 Detection limit: when the cuvette with optical path length of 20mm is used and the volume of the test portion is 100ml, the detection limit is 1μg/L.
1.5 Sensitivity: in this method, chloroform is used for extraction, when the measurement is carried out at the maximum light absorption wave length of 518nm, molar absorption coefficient is 8.56×104L/mol?cm.

2 Definition

As specified in this standard, total cadmium content in the water sample shall be determined after the water sample is subject to acid digestion treatment.