ISO 787-19:1974
General methods of test for pigments; part 19: determination of water-soluble nitrates (Salicylic acid method)
- Standard No.
- ISO 787-19:1974
- Release Date
- 1974
- Published By
- International Organization for Standardization (ISO)
- Status
- Replace By
- ISO 787-19:2020
- Latest
- ISO 787-19:2020
- Scope
- This document specifies a spectrophotometric method. The principle of the method consists in that the nitrate present in the extract of the sample is used to nitrate salicylic acid in sulphuric acid medium. The nitro-compound formed is of an intense yellow colour in alkaline solution and the colour is measured spectrophotometrically at a wavelength of 410 nm. ISO 787/13 specifies a method using Nessler's reagent. The two methods may not necessarily give the same result; work is being carried out to compare the two methods.
ISO 787-19:1974 history
- 2020 ISO 787-19:2020 General methods of test for pigments — Part 19: Determination of water-soluble nitrates (Salicylic acid method)
- 1974 ISO 787-19:1974 General methods of test for pigments; part 19: determination of water-soluble nitrates (Salicylic acid method)
