基于ATR-FTIR成像技术的川贝母粉末显微光谱鉴定

摘要

目的:建立一种简便快速的贝母粉末鉴定方法,以准确区分川贝母与其他贝母粉末,保证川贝母粉末的真实性.方法:使用ATR-FTIR成像技术直接测量贝母粉末的显微红外光谱,通过主成分分析和归一化相对峰强度法对测量结果进行定性和定量解析,寻找川贝母与其他贝母粉末的显微红外光谱差异特征.结果:不同品种贝母粉末的显微红外光谱图像中均存在三类主要像素,分别具有淀粉粒、蛋白质和细胞壁的特征吸收信号,而川贝母粉末中主要对应于淀粉粒的第一类像素数量最多.以1200~900 cm-1区域吸收峰面积为目标峰,以1700~1500 cm-1区域吸收峰面积为参比峰,计算像素平均归一化相对峰强度Rm值.川贝母粉末的Rm值稳定在0.70左右,显著高于其他贝母粉末,可以作为区分川贝母和其他贝母粉末的量化指标.结论:使用ATR-FTIR成像技术,可以建立简便快速、客观量化的贝母粉末显微光谱鉴定方法.%Objective:To establish a simple and rapid identification method for identification different kinds of Fritil-lariae Bulbus powder and ensure the authenticity of Fritillariae Cirrhosae Bulbus(FCB).Methods:The powder of different kinds of Fritillariae Bulbus was measured directly by ATR-FTIR microspectroscopic imaging.Principal component analysis and the normalized relative peak intensity method were used for the qualitative and quantitative interpretation of the microscopic ATR-FTIR spectra to find out the discriminative spectral features between FCB and other kinds of Fritillariae Bulbus.Results:Three kinds of microspectroscopic pixels,corresponding to starch grains,protein and cell wall,can be found in the ATR-FT-IR image of each sample.Meanwhile,the number of the pixels corresponding to starch grains was the largest in FCB.The nor-malized relative peak intensity Rmwas calculated using the band area in the region of 1200-900 cm-1as the target peak and the band area in the region of 1700-1500 cm-1as the reference peak.Rmfor FCB was always about 0.70,which was signifi-cantly larger than Rmfor other kinds of Fritillariae Bulbus.The Rmvalue can be used as the quantitative criterion to discriminate the FCB powder from the powder of other kinds of Fritillariae Bulbus.Conclusion:The microspectroscopic identification meth-od based on the ATR-FTIR imaging technique can be used for the simple,rapid,objective and quantitative identification of FCB.