Abstract：The objective of the present study is to analyze different products of Guilin watermelon frost by Fourier transform infrared spectroscopy (FTIR), second derivative infrared spectroscopy and two-dimensional correlation spectroscopy (2D-IR) under thermal perturbation. The structural information of the samples indicates that samples from the same factory but of different brands had some dissimilarities in the IR spectra, and the type and content of accessories of them were different compared with conventional IR spectra of samples, peaks at 638 and 616 cm-1 all arise from anhydrous sodium sulfate in watermelon frost spray and watermelon frost capsule; the characteristic absorption peaks of the sucrose, dextrin or other accessories can be seen clearly in the spectra of watermelon frost throat-clearing buccal tablets, watermelon frost throat tablets and watermelon frost lozenge. And the IR spectra of watermelon frost lozenge is very similar to the IR spectra of sucrose, so it can be easily proved that the content of sucrose in watermelon frost lozenge is high. In the 2D-IR correlation spectra, the samples presented the differences in the position, number and relative intensity of autopeaks and correlation peak clusters. Consequently, the macroscopical fingerprint characters of FTIR, second derivative infrared spectra and 2D-IR spectra can not only provide the information about main chemical constituents in medical materials, but also analyze and identify the type and content of accessories in Guilin watermelon frost. In conclusion, the multi-steps IR macro-fingerprint method is rapid, effective, visual and accurate for pharmaceutical research.
[1] Pharmacopoeia Committee of Ministry of Health, the People’s Republic of China(中华人民共和国药典委员会). Pharmacopeia of the People’s Republic of China(中华人民共和国药典). (Vol.Ⅰ). Beijing: Chemical Industry Press(北京: 化学工业出版社), 2010. [2] BAI Yan, SUN Su-qin, LI Jun, et al (白 雁, 孙素琴, 李 军, 等). Chinese Traditional Patent Medicine(中成药), 2005, 27(5): 544. [3] XU Rong, SUN Su-qin, XIN Shi-guang, et al(徐 荣, 孙素琴, 辛士光, 等). Journal of Infrared and Millimeter Waves(红外与毫米波学报), 2010, 29(5): 325. [4] WEI Ji-ping, SHAO Chun-fu, LI Chang-wen, et al(魏纪平, 邵春甫, 李长文, 等). Liquor-making Science and Technology(酿酒科技), 2010, (6): 51. [5] TU Ya, BAI Jin-liang, ZHOU Qun, et al(图 雅, 白金亮, 周 群, 等). Chinese Journal of Analytical Chemistry(分析化学), 2011, 39(4): 481. [6] Wu Y W, Sun S Q , Zhao J, et al. Journal of Molecular Structure, 2008, 883-884: 48. [7] Yao X, Peng Y, Zhou Q, et al. Journal of Molecular Structure, 2010, 974: 161. [8] Li Dan, Jin Z X, Zhou Q, et al. Journal of Molecular Structure, 2010, 974: 68.
