Thermogravimetric analysis (TGA) in oxidative conditions is a promising alternative to ignition in oven for the determination of inorganic residue, commonly referred to as ash. It is here shown that TGA can be used with temperature programs resembling those in standardized methods for oven ignition, and obtainequivalent results even though the sample amount is several orders of magnitude lower. The precision and limit of quantification of TGA is also discussed.