Comparative analysis of five kinds of rosewood by infrared spectra

In this paper we proposed the infrared spectrum analysis method in order to provide a new idea for identification of rosewood species. Five kinds of rosewood, Pterocarpus cambodianus, P. erinaceus, P. indicus, P. macarocarpus and P. pedatus were explored by FTIR, second derivative IR (SDIR) and two dimensional correlation infrared (2DIR) spectroscopy. The results showed that: 1) The difference at 781 cm-1 in the FTIR spectrum could differentiate P. cambodianus and P. erinaceus from the other three kinds of rosewood. 2) In the SDIR, an absorption peak at 1 179 cm-1 existed for P. erinaceus, that of P. macarocarpus occurred at 781 cm-1, P. pedatus had obvious absorption peaks at 1 351, 1 299, 1 147, 1 131 and 938 cm-1, while P. indicus had no absorption peaks. 3) In the 2DIR, the differences at 1 100, 1 150 and 1 258 cm-1 could separate P. erinaceus from the other rosewood; the differences at 1 467 and 1 518 cm-1 could distinguish P. cambodianus, P. erinaceus and P. pedatus. Applying SDIR solely could not distinguish these rosewood completely, but a combination of FTIR, SDIR and 2DIR could identify all these five kinds of rosewood and provide a new way for non-destructive detection of rosewood.