Use of visible and near infrared spectroscopy to predict klason lignin content of bamboo, Chinese fir, Paulownia, and Poplar

The use of calibrated visible and near infrared (NIR) (400-2500 nm) spectroscopy to predict the klason lignin content of Moso bamboo (Phyllostachys pubescens), Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.), Paulownia (Paulownia elongata), and Poplar (Populus nigra var.) samples was investigated. For bamboo, Chinese fir, and Paulownia, the lignin content predicted by means of chemical methods and that predicted by NIR are similar. The ratio of performance to deviation (RPD) of bamboo, Chinese fir, and Paulownia was 3.33, 2.53, and 1.77, respectively. However, for the poplar, the RPD was 1.07 only. The original models were constructed using a full spectrum ranging from 400 nm to 2500 nm. If the spectral range is reduced to the range of 400-1050 nm or 1100-2500 nm, a slight decrease in the quality of the models will occur. However, this decrease is minor considering the advantages of using a reduced spectral range. The results demonstrated that NIR could predict Klason Lignin Content of bamboo, Chinese fir, Paulownia, and Poplar.