ISO 3709:1976

Phosphoric acid for industrial use (including foodstuffs) — Determination of oxides of nitrogen content — 3,4- Xylenol spectrophotometric method

OVERVIEW

Applicable to products having a content, expressed as N, equal to or more than 0.2 mg/kg. Consists in oxidation of nitrous nitrogen to nitric nitrogen by potassium permanganate and reaction of nitrogen(V) with 3,4-xylenol under specified conditions to form a nitrate derivative. Subsequent destillation of the nitrate derivative and absorption in sodium hydroxide solution. Spectrophotometric measurement of the yellow nitrophenol at a wavelength of about 435 nm.

COMMENTS

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PRODUCT DETAILS

Status Withdrawn - 03 Jan 2024
Edition 1976
No. of Pages 4
ICS Classification 71.060.30 Acids
67.220.20 Food additives
Committee ISO/TC 47
Available for Purchase For sale in Singapore only
Adoption ISO