为了检测在不同湿度条件下西洋参品质的变化，根据分子结构改变引起荧光光谱变化的原理，对西洋参的活性成分进行在体检测。选用中心波长为254 nm的紫外光源激发西洋参检品发射荧光，利用基于可调液晶滤光器的光谱成像装置获取检品420～680 nm之间的连续荧光光谱图像。采用帧差法提取光谱立方体的有效区域并绘制特征光谱图。对存放于不同湿度条件下的三份西洋参检品连续检测，并绘制归一化特征光谱图。特征光谱图显示不同湿度对西洋参的影响趋势一样。利用饮片与对照品的加权欧氏距离反映西洋参的变化规律，湿度越大距离变化越快。检测结果反映出在不同湿度条件下西洋参活性成分随存放时间的变化，而且这种变化是不可逆的。

In order to detect the quality change of Panax quinquefolium in different humidity environments, the spectral imaging technology is applied to detect active constituent of Panax quinquefolium, based on the principle that variation of molecular structure causes variation of fluorescence spectrum. Ultraviolet ray source that with a central wavelength of 254 nm is used to stimulate the Panax quinquefolium sample to emit fluorescence. The continuous fluorescent spectrum image within the range 420～680 nm is got by adjustable liquid crystal light filter based spectrum imaging device. The frame differential method is used to extract the effective area of the spectrum cube and draw the characteristic spectrum image. Three Panax quinquefolius samples that are kept in different humidity conditions are detected, and the normalized characteristic spectrum diagram is drew. The characteristic spectrum shows that the change trend of relative intensity of fluorescence of Panax quinquefolium in different humidity environments are similar. Weighted Euclidean distance between comparison products and samples is utilized to show regularity of the change of Panax quinquefolium. The higher the humidity is, the faster the variation of weighted Euclidean distance is. The result shows that in different humidity environments, the active constituent of Panax quinquefolium will change with time, and this kind of change is irreversible.