中药是复杂的化学体系, 建立快速、有效的分析方法有助于中药水煎液的实时质量控制。 葛根在处方中常用有三种, 分别为粉葛、野葛和煨葛（葛根炮制品）, 且传统应用中多采用水煎煮的方式, 因此, 采用傅里叶变换红外光谱技术（FTIR）, 二阶导数光谱（SD-IR）, 结合二维相关红外光谱（2D-IR）对三种葛根水煎液进行快速分析。 结果表明, 通过FTIR和SD-IR光谱能够将粉葛水煎液明显区别于野葛和煨葛水煎液。 经过2D-IR分析, 发现野葛经过煨制后水煎液化学成分发生了变化, 二者在主要的自动峰和交叉峰的位置和强度方面存在较大差异, 在1 800~1 300 cm-1范围内, 野葛水煎液中最强的自动峰为1 556 cm-1, 次强峰为1 561 cm-1, 而在煨葛水煎液中最强自动峰为1 563 cm-1, 次强为1 572 cm-1, 再次为1 556 cm-1。 另外, 在野葛水煎液中出现了明显的1 536和1 634 cm-1自动峰, 二者的强度相当。 野葛及煨葛水煎液的2D-IR光谱中, 出现的自动峰1 448和1 518 cm-1的相对强度有较大的差异。 在野葛水煎液的2D-IR光谱中, 交叉峰（1 518, 1 561）和（1 518, 1 563） cm-1强于煨葛水煎液中相应峰。 凭借2D-IR自动峰和交叉峰可以较直观地鉴别野葛和煨葛水煎液, 并揭示二者相应各官能团的变化规律, 能够为葛根在临床处方应用过程中, 水煎液的快速质量控制提供依据。 利用FTIR, SD-IR结合2D-IR的整体性和宏观指纹性, 可以为中药等复杂体系的逐级鉴别提供快速、准确的方法和手段。

Traditional Chinese medicine is a complicated chemical mixture system. It is helpful for quality control of traditional Chinese medicine to establish a fast and effective analysis method. There are three kinds of Radix Puerariae in clinical, which are Pueraria thomsonii Benth, Pueraria lobata (Willd. ) Ohwi and simmered Pueraria lobata (Willd.) Ohwi (processed Radix Puerariae). Furthermore, aqueous extract is an important method for Radix Puerariae in clinical application. Therefore, a macroscopic IR fingerprint method, conventional Fourier transform infrared spectroscopy (FTIR) combined with second derivative infrared spectroscopy (SD-IR) and two-dimensional correlation infrared spectroscopy (2D-IR), was applied to quickly analyze aqueous extracts of three kinds of Radix Puerariae in this study. The results showed that aqueous extract of Pueraria thomsonii Benth was different from aqueous extracts of Pueraria lobata (Willd.) Ohwi and simmered Pueraria lobata (Willd.) Ohwi by FTIR and SD-IR. There were differences of Pueraria lobata (Willd.) Ohwi after simmered by 2D-IR analysis. There were distinctive differences of main auto-peaks and cross-peaks in position and intensity. In the range of 1 800~1 300 cm-1, the strongest auto-peak was at 1 556 cm-1, and the second one appeared at 1 561 cm-1 in 2D-IR spectra of aqueous extracts of Pueraria lobata (Willd.) Ohwi. However, the strongest auto-peak was at 1 563 cm-1, and the second one appeared at 1 572 cm-1 in 2D-IR spectra of aqueous extracts of simmered Pueraria lobata (Willd.) Ohwi. In addition, there were two obvious auto-peaks at 1 536 and 1 634 cm-1, whose intensities were equal in 2D-IR spectra of aqueous extracts of Pueraria lobata (Willd.) Ohwi. The relative intensities of auto-peaks at 1 448 and 1 518 cm-1 were different in the two 2D-IR spectra. The cross-peaks at (1 518, 1 561) cm-1 and (1 518, 1 563) cm-1 of aqueous extract of Pueraria lobata (Willd.) Ohwi were stronger than those in 2D-IR of aqueous extract of simmered Pueraria lobata (Willd.) Ohwi. Therefore, aqueous extracts of Pueraria lobata (Willd.) Ohwi and simmered Pueraria lobata (Willd.) Ohwi can be identified intuitively by auto-peaks and cross peaks in 2D-IR spectra, and the change laws of functional groups of them can be revealed. It can provide the basis for the fast quality control of Radix Puerariae decoction in the process of clinical prescription application. The method including FTIR, SD-IR and 2D-IR, is rapid and exact, and can provide the means to analyze the complicated chemical mixture systems step by step.