ISO 2991:1974

Nitric acid for industrial use — Determination of ammoniacal nitrogen content — Spectrophotometric method

OVERVIEW

Applicable to products containing more than 0.0001 % (m/m) of ammoniacal nitrogen. The procedure described is siutable for contents between 0.0001 % (m/m) and 0.0005 % (m/m). The principle of the analysis consists in distillation, with entrainment by steam, of the ammonia in the presence of an excess of sodium hydroxide and collection of the distillate in an excess of acid solution. Neutralization of the excess of acid and formation of the coloured complex by treatment with sodium phenate and sodium hypochlorite in the presence of acetone. Spectrophotometric measurement of the indophenol obtained at a wavelength of about 630 nm. Has also been approved by the IUPAC.

COMMENTS

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PRODUCT DETAILS

Status Withdrawn - 03 Jan 2024
Edition 1974
No. of Pages 5
ICS Classification 71.060.30 Acids
Committee ISO/TC 47
Available for Purchase For sale in Singapore only
Adoption ISO