ISO 3709:1976
Phosphoric acid for industrial use (including foodstuffs); Determination of oxides of nitrogen content; 3,4- Xylenol spectrophotometric method
- Standard No.
- ISO 3709:1976
- Release Date
- 1976
- Published By
- International Organization for Standardization (ISO)
- Status
- 2002-05
- Latest
- ISO 3709:1976
- Scope
- 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.
ISO 3709:1976 history
- 1976 ISO 3709:1976 Phosphoric acid for industrial use (including foodstuffs); Determination of oxides of nitrogen content; 3,4- Xylenol spectrophotometric method
