Simple calibrating method of sodium thiosulfate standard solution

Abstract

The invention discloses a simple calibrating method of a sodium thiosulfate standard solution, which is used for quickly determining available chlorine content in a chlorine-containing disinfectant and chlorine dioxide. The invention belongs to the field of chemical analysis. The method comprises the following steps: titrating a prepared sodium thiosulfate standard solution by using a substance with known or unknown available chlorine concentratio and an original sodium thiosulfate standard solution, and calculating the concentration of the standard solution by the iodimetric principle. Compared with the sodium thiosulfate standard volumetric solution calibrating method in Chinese Standard GB / T601-2002, the result difference of the method disclosed by the invention does not exceed 1%, and thus, the method disclosed by the invention can be used for testing available chlorine concentration with low accuracy requirements. The invention simplifies the analysis procedure, and thus, quickly obtains the result; the invention reduces the types of reagents, thereby lowering the analysis cost; the invention avoids using heavy metal chemicals and carcinogens, thereby eliminating heavy metal pollution and carcinogen threat; the error is small, and thus, the invention is suitable for testing available chlorine content in the product with low accuracy requirements, and is especially suitable for terminal users in need of testing available chlorine products.

Description

technical field [0001] The invention relates to a simple calibration method for a sodium thiosulfate standard solution, belonging to the field of chemical analysis. It is suitable for testing the available chlorine content of products that do not require high accuracy, especially for end users who need to test the available chlorine content of products. Background technique [0002] People in modern society often use chlorine-containing preparations or chlorine dioxide for bleaching and disinfection, and the available chlorine content is a primary indicator for testing the efficacy of such products. When analyzing available chlorine, it is necessary to prepare and calibrate 0.1mol / L sodium thiosulfate standard solution. The national standard GB / T601-2002 stipulates the calibration method of sodium thiosulfate standard titration solution. The method requires a dry and constant weight 0.54g reference reagent Potassium dichromate is used for calibration, but during the calibra...

AI Technical Summary

Problems solved by technology

[0003] Every chlorine-containing disinfectant and chlorine dioxide production plant, intermediary and end-user in China must detect the available chlorine content and calibrate the sodium thiosulfate solution. For continuous production, more standard solutions will be needed. It needs to consume a relatively large amount of potassium dichromate to operate according to the national standard.