Method for testing content of titanium dioxide by complexometric titration-back titration method

Abstract

The invention provides a method for testing content of titanium dioxide by a complexometric titration-back titration method. The method comprises the following steps of: (1) treating a sample; (2) optimizing an operation process, and reasonably adjusting the concentration of solution pH alkali; and (3) adding a buffer solution; and then calculating out the content of the titanium dioxide in the sample. By adopting the method provided by the invention, the acidity of the solution at the end point of titration can be controlled well, an indicator is ensured to change the color obviously, the precision of sample test is improved, and the relative deviation of the sample test result is less than 0.3%.

Description

technical field [0001] The invention relates to the field of chemical testing, in particular to a method for determining the content of titanium dioxide by complexometric titration back titration. Background technique [0002] Titanium dioxide, commonly known as titanium dioxide, is a white solid or powdery amphoteric oxide. Titanium dioxide is stable in nature, not easy to undergo chemical changes, and has strong adhesion, high melting point, non-toxic, and is the best white pigment. It is mostly used in photocatalysts. Cosmetics, and used to make fire-resistant glass, glaze, enamel, clay, high-temperature experimental vessels, etc. [0003] As an important chemical raw material, titanium dioxide is widely used in many fields, and the content of titanium dioxide directly affects the quality of the product. Therefore, the rapidity and accuracy of quantitative analysis of titanium dioxide have become an important criterion for the detection method. This method is mainly appl...

AI Technical Summary

Problems solved by technology

[0004] It is known that there are aluminum reduction method and complexometric titration method for the determination of titanium dioxide content. However, the aluminum reduction method requires specific analytical instruments and standard substances, and the analysis cost is high, which is greatly restricted in actual production.

Complexometric titration back titration is a commonly used analysis method in volumetric analysis. The principle is that excess disodium EDTA EDTA reacts quantitatively with metal ions to form a stable soluble complex, and the remaining disodium ethylenediaminetetraacetate Quantitative reaction with zinc titration solution can obtain the content of titanium dioxide in the sample. In complexometric titration, the acidity of the solution should not only be adjusted before titration, but also should be controlled within a certain range of acidity during the whole titration process, because in B During the titration process of disodium diaminetetraacetic acid, H+ is continuously released, which increases the acidity of the solution. Therefore, a certain amount of buffer solution must be added in the complexometric titration to control the acidity of the solution, and poor acidity control is harmful to the indicator. The discoloration has a greater impact, which affects the judgment of the end point, resulting in low precision of the test results, and needs to be appropriately improved