Application of two-dimensional near-infrared (2D-NIR) correlation spectroscopy to the discrimination of three species of Dendrobium

The objective of this paper was to apply two-dimensional (2D) near-infrared (NIR) correlation spectroscopy to the discrimination of three species of Dendrobium. Generalized 2D-NIR correlation spectroscopy was able to enhance spectral resolution, simplify the spectrum with overlapped bands and provide information about temperature-induced spectral intensity variations that was hard to obtain from one-dimensional NIR spectroscopy. The FT-NIR spectra were measured over a temperature range of 30-140°C. The 2D synchronous and asynchronous spectra showed remarkable differences within the range of 5600-4750 cm^-1 between different species of Dendrobium.