应用正交投影法对5种姜科植物药材的色谱峰进行鉴别。用对照组分光谱与目标色谱峰前后的零浓度区光谱构建正交投影阵,对目标色谱峰的光谱进行投影,以投影前后光谱的夹角余弦作为判据来鉴别目标色谱峰的峰纯度。对5种姜科植物药材色谱指纹图谱的峰纯度鉴别,识别出姜黄素纯色谱峰。正交投影法鉴别色谱峰的纯度结果可靠,背景的干扰可消除。 Orthogonal projection method was used to identify the chromatographic peaks of five ginger plants. An orthogonal projection array was constructed by using zero-concentration spectrum of the control component spectrum and the target chromatogram peak before and after, and the spectrum of the target chromatogram peak was projected. The peak angle purity of the target chromatogram peak was identified using the angle cosine of the before and after projection spectrum as a criterion. The peak purity of the chromatographic fingerprints of five ginger plants was identified and the pure chromatide peaks were identified. Orthogonal projection method is reliable in identifying the purity of chromatographic peaks, and the background interference can be eliminated.