GB/T 10513-2012Determination of free water for nitrophosphate - Karl fischer method (English PDF)

1 Scope

This standard specifies the determination of P and K fertilizer nitrate, the free water content by the Karl Fischer method.

This standard applies to all kinds of technology, the nitrate fertilizer, measuring water content of phosphorus and potassium nitrate free.

2 Normative references

The following documents for the application of this document is essential. For dated references, only the dated edition applies to this

File. For undated references, the latest edition (including any amendments) applies to this document.

GB/T 6283 Determination of chemical products, water content Karl Fischer method (General method) (GB/T 6283-2008, ISO 760. 1978, NEQ)

GB/T 10511-2008 After distillation of total nitrogen content for nitrophosphate titration

HG/T2843 fertilizer products commonly used standard titration solution, standard solution, reagent solution and indicator solution Chemical Analysis

Principle 3

Free water sample with a known water titer of Karl Fischer reagent for quantitative reaction, reaction is as follows.

H2O I2 SO2 3C5H5N = 2C5H5N · HI C5H5N · SO3

C5H5N · SO3 CH3OH = C5H5NH · OSO2OCH3

4 Reagents

Reagents and solutions following the flammable and toxic and harmful to the human body, the operator should be careful! If splashed on the skin should be washed with water immediately

Wash, if not meet the doctor immediately.

This standard reagent solution and water, in the specifications and method of preparation is not specified, it shall comply with the provisions of HG/T2843's.

5 Instruments