SU649460A1 - Burette - Google Patents

Description

one

The invention relates to titration devices and can be used in analytical chemistry, in industrial process control.

Titration burettes are known that end in a capillary to iodine the solution above the surface of the titrated solution.

With such a supply, the titrating solution occurs in B: Isania drops on the capillary. At the same time, the size of a droplet is influenced by a number of factors that are different for different liquids (surface tension, temperature, etc.). Therefore, the magnitude of the error associated with a different drop size cannot always be taken into account. The minimum dose delivered with this solution delivery method is a drop, the value of which is much higher than the burette calibration value, and the titration curve is stepped. Flowing drops to the surface increases the mixing time.

A titration burette is also known, including, and a titrant tank and a capillary tube with a tip connected to the tank.

However, in the well-known burette, the solution from the cell penetrates into the capillary and beyond during periods when no titration solution is supplied (discrete titration) and especially when the titrated solution is not completely drained by the titration method.

subsequent titrations (for example, when determining moisture with K. Fischer's reagent). Because of this, before each titration it is necessary to drain a certain amount of the titrating solution and neutralize it.

in some way in the cell. This complicates the titration process, takes too much time, increases the consumption of the titrating solution.

A capillary narrowed at the end reduces the amount of diffusion, but does not exclude it at all. At the same time, in the buret-capillary system, the pressure rises, which leads to an increase in the technical requirements for this system (increased requirements for cylinder seals with a piston, tightness of a switching valve or valves), and in gravity burettes increases the titration time. The capillary becomes critical to the purity of the titrant in terms of mechanical inclusions.

In order to improve the titration accuracy by eliminating the diffusion of the titrated solution into the titrant, the burette is equipped with a chamber placed with a tip.

The drawing shows a burette, a general view with a partial cut.

The titration burette consists of a tank 1 for the titrant, a capillary 2, having a chamber 3 located at the lower end, and a tip 4.

At the beginning of the nodachi of the titrating solution from the tank / he, the stack goes through the capillary 2, and then along the inner walls of the chamber 3 enters the tip 4. At the same time, a certain amount of air or gas is blocked in the cavity of the chamber 3. After stopping the supply, the titrating solution stops flowing along the walls of chamber 3 and this separates this solution from the chamber 3, which is titrated by the cavity, filled with air or gas.

The length of the tip 4 is chosen such that the volume of the solution mixed in it does not affect the result of the titration.

Eliminating the diffusion of titrated into the titrating separation of these solutions with a chamber with air or gas, the proposed burette allows the use of larger-sized capillaries, which facilitates the operation and consumption of the titrating solution, and increases the accuracy of titration.

Claims (1)

Invention Formula A titration burette including a tank for the titrant and a capillary tube with a tip connected to the tank, characterized in that, in order to increase the accuracy of the titration by excluding diffusion of the titrated solution into the titrant, it is provided with a chamber placed in front of the tip.