What is difference between residue on ignition and sulphated ash?
- Residue on ignition(ROI) means sample is ignited at high temperature and the remaining is the ash. As per USP it is Residue on ignition (Ignited at 800°C +/- 50°C)
- Sulphated ash means in the above ash add conc. sulfuric acid. As per BP and Ep it is called as Sulphate ash (ignition
temperature of 600°C +/- 25°C).