College of Chemistry & Chemical Engineering, Lanzhou University, Lanzhou 730000, PR China.
Anal Chim Acta. 2010 Jan 11;657(2):131-5. doi: 10.1016/j.aca.2009.10.042.
High-performance liquid chromatography (HPLC) fingerprint has been commonly used in the quality control and assessment of herbal medicines, and two-dimensional (2D) fingerprint obtained by means of HPLC-diode array detector (HPLC/DAD) can provide higher reliability. In this paper, an approach to the analysis of the 2D HPLC/DAD fingerprints, which was based on digital image recognition techniques, was developed for the first time. First, wavelet transform was employed to eliminate noise signal in the 2D fingerprint, and then the 2D fingerprint was converted into grayscale image. Second, several features of the image were calculated, and hierarchical clustering. This approach was applied to the qualitative analysis of the different samples of coptis chinensis, and the clustering result of samples was all highly consistent with the real situation. Based on the densities in grayscale image, three components in standard samples were quantitative analyzed, and the obtained correlation coefficients between concentration and grayscale density were more than 0.999. Our study indicated that the analysis of the 2D HPLC/DAD fingerprint was successful based on the idea and techniques of digital image recognition techniques, and this proposed approach provided a new pathway for the analysis of two-dimensional spectrums.
高效液相色谱（HPLC）指纹图谱已广泛用于中药材的质量控制和评估，而通过高效液相色谱-二极管阵列检测器（HPLC/DAD）获得的二维（2D）指纹图谱可以提供更高的可靠性。本文首次开发了一种基于数字图像识别技术的 2D HPLC/DAD 指纹图谱分析方法。首先，采用小波变换消除 2D 指纹图谱中的噪声信号，然后将 2D 指纹图谱转换为灰度图像。其次，计算图像的几个特征，并进行层次聚类。该方法应用于不同黄连样品的定性分析，样品的聚类结果与实际情况高度一致。基于灰度图像的密度，对标准样品中的三个成分进行定量分析，得到的浓度与灰度密度之间的相关系数均大于 0.999。我们的研究表明，基于数字图像识别技术的思想和技术，成功地分析了 2D HPLC/DAD 指纹图谱，该方法为二维光谱分析提供了新的途径。
