Standard No.:	GB 7472-1987
English Name:	Water quality - Determination of zinc - Spectrophotometric method with dithizone
Chinese Name:	水质 锌的测定 双硫腙分光光度法
Chinese Classification:	Z16    Analysis methods for toxic substances in water
Professional Classification:	GB    National Standard
Source Content Issued by:	AQSIQ
Issued on:	1987-3-6
Implemented on:	1987-8-1
Status:	valid
Target Language:	English
File Format:	PDF
Word Count:	3000 words
Translation Price(USD):	60.0
Delivery:	via email in 1 business day

1 Application Scope 1.1 Determination substance: this standard specifies determination of zinc in water by spectrophotometric method with dithizone. 1.2 Sample type: this method is applicable to determination of trace zinc in natural water and some waste water. Relevant interference problems are detailed in Appendix A. 1.3 Scope: this method is applicable to determine water sample with zinc concentration of 5~50μg/L. 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 5μg/L. 1.5 Sensitivity: in this method, carbon tetrachloride is used for extraction, when the measurement is carried out at the maximum light absorption wave length of 535nm, the molar absorbance is about 9.3×104L/mol•cm. 2 Definition As specified in this standard, total zinc content in the water sample shall be determined after the water sample is subject to acid digestion treatment.

Contents 1 Application Scope 2 Definition 3 Principle 4 Reagent 5 Apparatus 6 Sampling and Sample 7 Procedures 8 Expression of Results 9 Precision and Accuracy Appendix A (Supplement) Interference and Its Elimination Additional Explanation