ISO 2144: 2015 describes the determination of the residue on ignition of pulps, papers, and boards. The International Standard is applicable to all types of pulp, paper, and board. The lower limit of the determination is about 0.2%.
NOTE The procedure (Clause 7) requires that at least 10 mg of residue is weighed. The limit stated above corresponds to a 5 g sample. If the sample size is increased, this limit can be lowered.