Baseline Correction Method for Raman Spectroscopy Based on B-Spline Fitting
WANG Xin1, FAN Xian-guang1*, XU Ying-jie1, WU Jing-lin1, LIANG Jun1, ZUO Yong2
1. School of Physics and Mechanical & Electrical Engineering, Xiamen University, Xiamen 361005, China 2. Changcheng Institute of Metrology & Measurement, The 1st Metrology & Measurement Research Center of National Defense Science Industry of China, Beijing 100095, China
Abstract：Baseline drift is a widespread phenomenon in modern spectroscopy instrumentation, which would bring a very negative impact to the feature extraction of spectrum signal, and the baseline correction method is an important means to solve the problem, which is also the important part of Raman signal preprocessing. The general principle of baseline drift elimination is using the fitting method to the fit the baseline. The traditional fitting method is polynomial fitting, but this method is prone to over-fitting and under-fitting, and the fitting order is difficult to be determined. In this paper, the traditional method is improved; the B-spline fitting method is used to approach the baseline of Raman signal through constant iteration. The advantages of B-spline, namely low-order and smoothness, can help the method overcome the shortcomings of polynomial method. In the experiments, the Raman signal of malachite green and rhodamine B were detected, and then the proposed method and traditional method were applied to perform baseline correction. Experimental results showed that the proposed method can eliminate the Raman signal baseline drift effectively without over- and under-fitting, and the same order can be used in both positions where large or small baseline drift occurred. Therefore, the proposed method provided more accurate and reliable information for the further analysis of spectral data.
[1] Chalmers J M, Griffiths Peter R. Handbook of Vibrational Spectroscopy (Vol 1-5). Wiley, 2003. [2] E Smith, G Dent. Modern Raman Spectroscopy—A Practical Approach. John Wiley & Sons Ltd., 2004. [3] Geiman I, Leona M, Lombardi J R. J. Forensic. Sci., 2009, 54(4): 947. [4] Oh C, Yoon S, Kim E, et al. Journal of Pharmaceutical and Biomedical Analysis, 2010, 53(3): 762. [5] Matousek P. Chem. Soc. Rev., 2007, 36(8): 1292. [6] DOU Li-yan, ZHANG Wan-xi, ZHANG Yu-jie, et al(窦丽艳, 张万喜, 张玉杰，等). Chinese Journal of Analytical Chemistry(分析化学), 2006, 31(11): 1615. [7] McCreer R L. Raman Spectroscopy for Chemical Analysis. Wiley-Interscience, 2000. [8] Schrader B. Infrared and Raman Spectroscopy—Methods and Application. Wiley-VCH, 1995. [9] Vincent M, Ce’dric C, David B, et al., Chemom. Intell. Lab. Syst., 2005, 76: 121. [10] Feng Xinwei, Zhu Zhongliang, Shen Mengjie, et al. Computer and Applied Chemsity, 2009, 26(6): 759. [11] Jagtiani A V, Sawant R, Carletta J, et al., Measurement Science and Technology, 2008, 19: 065102. [12] HOU Si-zu, JIAN Yan-hong, LI Cheng(侯思祖, 简燕红, 李 程). Computer Simulation(计算机仿真), 2010, 27(3): 366. [13] Renner G, Wei V. Computer-Aided Design, 2004, 36(4): 351. [14] GUO Jian-feng, ZHU Chang-qing(郭建锋, 朱长青). Engineering of Surveying and Mapping(测绘工程), 2000, 9(4): 25. [15] Li Jianfeng, Huang Yifan, Ding Yong, et al. Nature, 2010, 464: 392.
