International Organization for Standardization (ISO)
Latest
ISO 9648:1988
Scope
The method consists in extraction by shaking with dimethylformamide, then after centrifuging, addition of ferric ammonium citrate and ammonia to an aliqiot part of the supernatant liquid and spectrometric determination, at 525 nm, of the absorbance of the solution thus obtained, and determing of the tannic content using a calibration curve prepared using tannic acid.
ISO 9648:1988 history
1988ISO 9648:1988 Sorghum; determination of tannin content