GB/T 9732-2007Chemical reagent -- General method for the determination of ammonium (English PDF)

Foreword

This standard and ISO 6353-1. 1982 "Reagents for chemical analysis - Part 1. General test method" non-equivalent.

This standard replaces GB/T 9732-1988 "General method for the determination of ammonium chemical reagents." This standard did not differ from the 1998 version of the standard in technical content, according to GB/T 1.1-2000 requirements, just to do some editing Modifications. The standard proposed by China Petroleum and Chemical Industry Association.

1 Scope

This standard specifies the determination of ammonium visual colorimetry with Nessler reagent - General method.

This standard applies to the determination of trace amounts of ammonium chemical reagent. Detection range of 0.05µg/mL ~ 1µg/mL (in NH4 dollars).

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.

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 6682-1992, neq ISO 3696. 1987)

3 PRINCIPLE OF THE METHOD

In alkaline solution, the free ammonia or ammonium bound Nessler reagent to produce a light yellow to reddish brown insoluble compound. Ammonium content Higher, and the resultant reddish-brown precipitation; ammonium content is low, the formation of a stable suspension can be used ammonium visual colorimetric method.

4 Reagents and materials

Unless otherwise specified in this standard, the standard solution, preparations and products, according to GB/T 602, the provisions of the preparation of GB/T 603, the experimental Water should be consistent with GB/T 6682 in the three water specifications.

5 Determination

Sampling according to product standards and the preparation of test solution is diluted to about 75mL, add 3mL sodium hydroxide solution (320g/L) and 2mL Carolina Grignard reagent, diluted to 100mL, shake. The yellow solution comparison with the standard colorimetric solution.

Preparation of standard solution of color than is specified amount of ammonium (NH4) standard solution is diluted to about 75mL, and at the same time with the same volume of test solution deal with.