采用二维相关红外技术,并借助于变温过程所跟踪的动态光谱对蒙药生草乌进行了分析研究。蒙药生草乌和制草乌的一维谱图较相似,导数光谱进一步分析,1 745,1 468,1 337 cm^-1处吸收峰在经过酸奶炮制之后向底波数位移,1 657 cm^-1处吸收峰在经过炮制之后向高波数位移,而二维红外相关谱则差别较大,在1 300~800 cm^-1波数范围内,生品的二维红外光谱存在3个主要的自动峰(1 650,1 560,1 470cm^-1),其中以1 560 cm^-1峰最强。自动峰和交叉峰形成明显的3×3的对称分布,均为正相关;制草乌在这一范围内的自动峰主要在4个区域,1 220与1 200 cm^-1两个吸收峰组成的一个区域,1 140和1 070 cm^-1两个尖锐的峰区,以及1 000~900 cm^-1区域内宽大重叠的峰,各自动峰均为正相关。凭借二维红外相关谱上的自动峰和交叉峰可以较直观地鉴别生草乌和制草乌,而且还可以揭示两者相应各官能团的变化规律。该法快速、准确,可为鉴别药材加工后结构的变化规律提供一种新的方法和手段。
2D-IR correlation spectroscopy and dynamic spectra tracked during mutative temperature process were used to do the research. The FTIR spectra of aconiturn kusnezoffii Reichb. and its processed products are similar, the result by second derivative spectrum was analyzed, the absorption peaks at 1 745, 1 468 and 1 337 cm^-1 shifted to the low wave number, while the absorption peak at 1 657 cm^-1 shifted to the high wave number after being processed with acidophilus milk. Obvious differences are observed between 2D-IR spectra of them, active peaks of aconitum kusnezoffii Reichb. 1 650, 1 560 and 1 470 cm^-1 were recorded in the region of 1 300-800 cm^-1 , and the strongest was at 1 560 cm^-1. Automatic peaks and cross peaks presented a symmetric distribution of 3 × 3, and all were positive correlation. Automatic peaks of processed aconitum kusnezoffii Reichb. in the region were in four areas, one was 1 220 and 1 200 cm^-1 , the second was sharp peaks of 1 140 and 1 070 cm^-1 , the third was wide peaks in the region of 1 000-900 cm^ -1, and all the automatic peaks were positive correlation. Therefore, aconiturn kusnezoffii Reichb. and its processed products can be identified intuitively by automatic and cross peaks of 2D-IR spectra, and the change laws of functional groups of them can be revealed. The method is rapid and exact, and can provide the means to analyze the structures' change laws of aconitum kusnezoffii Reichb. after being processed.