BS ISO 7766:2003
Processing photographic wastes - Analysis of cyanides - Determination of hexacyanoferrate(II) and hexacyanoferrate(III) by spectrometry
- Standard No.
- BS ISO 7766:2003
- Release Date
- 2003
- Published By
- British Standards Institution (BSI)
- Latest
- BS ISO 7766:2003
- Replace
- 00/717547 DC:2000 BS ISO 7766-1:1996
- Scope
- This International Standard establishes a test method for the determination of hexacyanoferrate (II) (ferrocyanide) and hexacyanoferrate (III) (ferricyanide), referred to hereafter as Fe (CN)6, in photographic processing effluents. Results are reported as hexacyanoferrate, Fe (CN)6. note: 1) Significant levels of thiosulfate (hypo) can result in interference. Significant levels of thiosulfate in processing-machine effluents result in oxidation of the thiosulfate by iron (III). Sulfur will form, increasing the spectrophotometric absorbance which is measured. Also, thiosulfate may deplete the added iron (III) leaving nothing for the colour reaction. The method is applicable to effluents from buildings where the thiosulfate would be diluted by the rest of the building wastes and this would eliminate the interference.
BS ISO 7766:2003 history
- 2003 BS ISO 7766:2003 Processing photographic wastes - Analysis of cyanides - Determination of hexacyanoferrate(II) and hexacyanoferrate(III) by spectrometry
