Method for measuring mercury content by using gas-phase molecular absorption spectrometer

Abstract

The invention relates to a method for measuring mercury content by using a gas-phase molecular absorption spectrometer. The method comprises the following steps of diluting a mercury standard stock solution step by step by using a hydrochloric acid solution to prepare a mercury standard working solution; detecting the mercury standard working solution by using a gas-phase molecular absorption spectrometer, and correspondingly drawing a standard curve by using the detection data and the concentration; detecting a to-be-detected water sample by adopting a gas-phase molecular absorption spectrometer, and finding the concentration of mercury according to the drawn standard curve by adopting detection data of the to-be-detected water sample; wherein the gas-phase molecular absorption spectrometer adopts two paths of sample injection, one path of sample injection being a mercury standard working solution or a to-be-detected water sample and a potassium dichromate-hydrochloric acid solution,the other path of sample injection being a KBH4 solution, and the two paths of sample injection being performed at the same time and being mutually converged. Compared with the prior art, the method is advantaged in that the standard solution is very stable and can be stored for a long time, detection sensitivity of the method is high, the determination result is accurate and stable, and operationis convenient.

Description

technical field [0001] The invention relates to a method for measuring mercury in sewage, in particular to a method for measuring mercury content by using a gas-phase molecular absorption spectrometer. Background technique [0002] HNO 3 +K 2 Cr 2 o 7 Preparation, the assay medium is NH 2 OH.CL reduces excess KMnO 4 , then use SnCL 2 Reduction of divalent Hg 2+ as elemental Hg 0 The absorbance of mercury atom gas was measured. However, HNO 3 +K 2 Cr 2 o 7 medium does not guarantee divalent Hg 2+ stable, and often volatile elemental Hg 0 , so that the concentration of the standard solution gradually decreases. SnCL 2 Reduction of divalent Hg 2+ as elemental Hg 0 , only suitable for low concentration 1mol / L HCL medium, higher concentration HCL medium SnCL 2 The reduction efficiency is very low, but when the hydrochloric acid medium is lower than 1mol / L, SnCL 2 It will also be hydrolyzed and precipitated to block the liquid path, or even impossible to measur...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a method for measuring mercury content using a gas phase molecular absorption spectrometer in order to overcome the defects of low detection sensitivity, many reagents used in the measurement method, and complicated operations in the above-mentioned prior art.