GB/T 2441.3-2010Determination of urea - Part 3: Water content - Karl Fischer method (English PDF)

1 Scope

This part of GB/T 2441 specifies the use of Karl Fischer method for the determination of moisture in urea.

This part applies to the determination of urea moisture from ammonia and carbon dioxide synthesis.

At the time of arbitration, the use of pyridine-containing Karl Fischer reagent.

2 normative reference documents

The terms of this document are the terms of this part by reference to this part of GB/T 2441. Any reference to the date of the text , All subsequent amendments (excluding corrigenda) or revisions do not apply to this part, however, encouragement under this section

The parties to the agreement study whether the latest version of these documents can be used. For undated references, the latest edition of this document applies section.

GB/T 6283 Determination of moisture content in chemical products Karl Fischer method (general method)

HG/T 2843 chemical analysis of chemical fertilizers commonly used standard titration solution, standard solution, reagent solution and indicator solution

3 principle

The moisture present in the sample is quantitatively reacted with the Karl Fischer reagent with known water droplet degree. The reaction is as follows.

H2O I2 SO2 3C5H5 -> N 2C5H5N · HI C5H5N · SO3

C5H5N · SO3 CH3 -> OH C5H5NH · OSO2OCH3

4 reagent

The following parts of the reagents and solutions flammable and toxic to humans, the operator should be careful such as splashing on the skin should be immediately washed with water

Wash or fit the way to deal with, if not suited to immediate medical treatment.

The reagents, solutions and water used in this section shall comply with the requirements of HG/T 2843 when not specified and formulated.

5 instruments

Karl Fischer direct power titration equipment, the typical device according to GB/T 6283 configuration.

6 Analysis steps

Make two samples in parallel.