采收是中药生产的重要环节, 采收时间直接影响中药质量和产量, 是中医临床安全有效用药的前提, 开展中药适时采收期的研究具有重要意义和应用价值。 采用傅里叶变换红外光谱法对72份不同采收期的滇龙胆进行鉴别研究, 用TQ8.0软件对原始光谱进行一阶导数(first derivative, FD)、 二阶导数(second derivative, SD)、 标准正态变量(standard normal variate, SNV)、 多元散射校正(multiplicative scatter correction, MSC)和平滑(savitaky-golay filter, SG)预处理, 样品按3∶1分为校正集和预测集, 同时建立主成分分析(principal component analysis, PCA)和偏最小二乘判别分析(partial least square discriminant analysis, PLS-DA)模型。 结果显示, 选取1　800～600 cm-1波段范围的光谱, 去除光谱噪音； SNV结合二阶导数光谱和SG(15, 3)平滑, 预处理结果满意。 主成分分析表明, 前三个主成分方差贡献率为92.47%, 5月、 9月和10月份采收的样品差异较小。 偏最小二乘判别分析建立判别模型, 决定系数R2和校正均方根误差(RMSEE)分别为0.967 8和0.086 0, 可对18个预测集样品进行准确分类。 红外光谱法结合主成分分析、 偏最小二乘判别分析对不同采收期滇龙胆的分类和判别效果较好, 为不同采收期的中药鉴别提供理论依据。

The harvest time of traditional Chinese medicine (TCM) is a very essential part for the production and quality of TCM which is the prerequisite for safe and effective clinical use of TCM. It is of great importance to carry out the research of timely harvest time of TCM. With Fourier transform infrared spectroscopy (FTIR) to study harvest time of Seventy-two Gentiana Rigescens samples. First derivative, second derivative, standard normal variate, multiplicative scatter correction and Savitaky-Golay(15,3) smoothing of all original spectra were pretreated with TQ8.0 software. Samples were divided into calibration set and prediction set at the ratio of 3∶1. Principal component analysis (PCA) and partial least square discriminant analysis (PLS-DA) model were established. The result indicated that after removing noise spectrum, the spectra range was from 1 800 to 600 cm-1, the method SNV combined with SD and SG present the best result of spectra pretreatment. The contribution rates of first three principal components were 92.47% with PCA. Small differences were found for the samples harvested in May, September and October. Same spectrum range was chosen and PLS-DA was applied to establish the model. The R2 and RMSEE were 0.967 8, 0.086 0, respectively, and the prediction accuracy is 100%. The methods of PCA and PLS-DA have good ability to classify and identify different harvest time of Gentiana Rigescens. It provided a basis for the identification of different harvest time of TCM.