Adaptive Titration Method for Potassium Permanganate Index

Abstract

The present invention provides an adaptive titration method for the potassium permanganate index, comprising the following steps: (A1) dropping a volume V into the water sample 0 The potassium permanganate solution is obtained and stirred, the stirring speed is ω, and the temperature of the water sample is T; obtain the time t required by the drop of potassium permanganate solution in the water sample to the color of the water sample dissipating; (A2) Using the mapping relationship V=f(V 0 , T, t, ω), obtain the predicted total titration volume V; if the total titration volume V exceeds the threshold V m , enter step (A3); if the total titration volume V does not exceed the threshold V m , enter step (A4); (A3) at the first speed v 1 In the water sample, drop the potassium permanganate solution with volume of (V-A), A is the set value, and stir, enter step (A4); (A4) with the second speed v 2 Add potassium permanganate solution dropwise to the water sample, v 2 <v 1 , until the end point of the titration. The invention has the advantages of high efficiency, automation and the like.

Description

technical field [0001] The invention relates to water sample detection, in particular to an adaptive titration method of potassium permanganate index. Background technique [0002] Manual titration and automatic titration of water quality permanganate index (IMN) need to judge whether the titration end point is reached while dripping, and the detection takes a long time. [0003] According to the national standard GB11892-1989, the existing detection method of permanganate index adopts the method of heating the water sample in a water bath and titrating potassium permanganate. The method requires manual operation, including quantitative addition of 100ml water sample to the conical flask, quantitative addition of various chemical reagents, water bath timing for 30min±2min, manual potassium permanganate titration, and visual judgment of the titration results. During titration, the temperature of the water sample should be kept at 60-80 °C, and the water sample should be titr...

AI Technical Summary

Problems solved by technology

[0006] 1. Since the constant rate titration is adopted, that is, the titration is carried out drop by drop in the form of dropping one drop at a fixed interval, which consumes a long time and the analysis efficiency is low

[0007] 2. Because it adopts the heating plate heat preservation method, the temperature of the water sample is not directly monitored. Under different temperature, humidity and ventilation environments, the temperature of the water sample may exceed the temperature range required by the national standard, which will affect the accuracy of the measurement results.

Images