Standard No.:	GB 7470-1987
English Name:	quality - Determination of lead - Spectrophotometric method with dithizone
Chinese Name:	水质 铅的测定 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 This standard is applicable to the determination of trace of lead in the natural water and waste water, the concentration of lead is between 0.01~0.30mg/L. When the concentration is greater than 0.30mg/L, the determination may be carried out after the proper dilution of the sample. 1.1 Detection limit: when the cuvette with 10mm optical path length is used, the volume of the test portion is 100mL, the 10mL dithizone is used for extraction, the minimum detectable concentration may be 0.010mg/L. 1.2 Sensitivity: the carbon tetrachloride is used for extraction, when the measurement is carried out under the maximum light absorption wave length of 510nm, the molar absorption coefficient is about6.7×104L/mol•cm. 2 Definitions The total lead in the water sample is determined after the acid decomposition in the standard.

Contents 1 Application Scope 2 Definitions 3 Principle 4 Reagents 5 Apparatus 6 Sampling and Sample 7 Procedure 8 Expression of Result 9 Precision and Accuracy Additional Explanation