GB/T 696-2008Chemical reagent - Urea (English PDF)

1 Scope

This standard specifies the chemical reagent urea characteristics, specifications, testing, packaging and inspection rules and signs.

This standard applies to chemical agents urea test.

2 Normative references

The following documents contain provisions which, through reference in this standard and become the standard terms. For dated references, subsequent

Amendments (not including errata content) or revisions do not apply to this standard, however, encourage the parties to the agreement are based on research

Whether the latest versions of these documents. For undated reference documents, the latest versions apply to this standard.

Preparation of GB/T 601 chemical reagent standard titration solution

GB/T 602 Determination of impurities in chemical reagents prepared standard solution (GB/T 602-2002, ISO 6353-1. 1982, NEQ) with

GB/T 603 chemical reagent test method Preparations of articles (GB/T 603-2002, ISO 6353-1 with. 1982,

NEQ)

GB/T 6682 analytical laboratory use specifications and test methods (GB/T 6682-2008, ISO 3696. 1987, MOD)

GB/T 9728 General method for determination of chemical reagents sulfate (GB/T 9728-2007, ISO 6353-1. 1982, NEQ)

GB/T 9729 General method for determination of chloride Chemicals (GB/T 9729-2007, ISO 6353-1. 1982, NEQ)

GB/T 9735 General method for determination of heavy metals Chemicals (GB/T 9735-2008, ISO 6353-1. 1982, NEQ)

GB/T 9738 Determination of water insoluble chemical reagent - General method (GB/T 9738-2008, ISO 6353-1. 1982, NEQ)

GB/T 9739 General method for determination of iron chemical reagents (GB/T 9739-2006, ISO 6353-1. 1982, NEQ)

GB/T 9741-2008 Determination of residue on ignition Chemicals General method (ISO 6353-1. 1982, NEQ)

GB 15346 chemical reagent packaging and marking

HG/T 3484 standard chemical reagents glass emulsion and clarity standards

HG/T 3921 Chemicals sampling and acceptance rules

3 Characters

This reagent is a colorless or white crystalline powder, soluble in water.

4 Specification

Urea as shown in Table 1.

Table 1

Name AR chemically pure

Content (H2NCONH2), /% >=99.0 >=99.0

Clarity test/number <=2 <=4

Water-insoluble, /% <=0.005 <=0.02

Residue on ignition (Sulfate), /% <=0.01 <=0.02 […]