Klason lignin: Modifications to improve the precision of the standardized determination

The lignin content in wood is generally determined with a standardized method. It is shown that with minor modifications, e. g., particle size, temperature and adherence to handling times, the standard deviation could be decreased substantially. Pooled standard deviations of 0.045 %, based on 30 determinations in immediate succession. and 0.11 %, based on 400 determinations in randomized order, were obtained, which are well qualified for the calibration of secondary analytical methods such as NIR or Raman spectrometry. As a consequence of finer grinding, an identical sample can be used for lignin determination and for investigations in the mid infrared region without regrinding or fractionating.