Wavelength Identification of Red Betel Leaf (Piper Crocatum), Green Betel Leaf (Piper Betle L.) and Black Betel Leaf (Piper Betle V.) Using Ultraviolet-Visible (UV-Vis) Spectroscopy Method Coupled with Principal Component Analysis (PCA)

摘要

Research has been conducted for wavelength identification of red betel leaf (Piper Crocatum), green betel leaf (Piper Betle L.), and black betel leaf (Piper Betle V.) using Ultraviolet-Visible (UV-Vis) spectroscopy method. This study aims to determine the specific wavelength identification of each betel leaf based on UV-Vis spectroscopy data. The experiment was started by weighing 1.9 g of red, green, and black betel leaf powders and dissolved of each sample in 25 ml of methanol, then immersed for 24 hours. Prior to be analyzed by UV-Vis spectroscopy, the sample diluted by 50 times. For classifying and discriminating of each betel leaf, the UV-Vis spectra data were then analyzed by using Principal Component Analysis (PCA) algorithm. The score plot result of PCA show that the cluster of each betel leaf separated clearly. Based on loading plot of PCA, the identity of betel leaf wavelength are in the range of 407-412 nm and the specific wavelength of this species is 408 nm. Each wavelength characteristics of red, green, and black betel leaf are 411 nm, 411.5 nm, and 409.5 nm, respectively.