紫外光谱法结合化学计量法鉴别茶油掺假的研究
Identification of tea oil adulteration by ultraviolet spectrum combined with chemometrics
-
摘要: 采用紫外光谱法结合化学计量法对茶油掺假鉴别进行研究。对纯茶油与掺假花生油、掺假菜籽油、掺假棕榈油样品进行紫外光谱扫描。结果表明,3 种掺假样品与纯茶油的紫外光谱有不同程度的差异。光谱数据在200~400 nm 波长范围内经过平滑后,采用主成分分析法进行数据压缩,通过建立模型进行识别,并对主成分进行投影。3 种掺假样品的前3 个主成分的累计可信度均达到要求;在二维组合投影中,3 种掺假油的PC1 对PC2 的投影分布最好,不同掺假比例的花生油、菜籽油和棕榈油与纯茶油的投影可明显区分,且掺假比例越大,掺假样品与纯茶油投影的鉴别效果越好;纯茶油与3 种掺假油样品的鉴别效果顺序为:掺假花生油> 掺假菜籽油> 掺假棕榈油。紫外光谱法结合化学计量法可作为一种简单、可靠的方法用于鉴别茶油的掺假。关Abstract: An approach of ultraviolet(UV)spectra combined with chemometrics was used to identify the adulteration of tea oil in this study. The pure tea oil and adulterated peanut oil,adulterated rapeseed oil,adulterated palm oil samples were scanned by UV spectra. The results showed that,the ultraviolet spectra of pure tea oil and three adulterated samples were different. The spectral data were smoothed in the wavelength range from 200 to 400 nm,then were compressed by using principal component analysis,and were recognized by establishing model and the principal component were projective. The results showed that,the cumulative credibility of the first three principal components of three adulterated samples also achieved the requirement. In the two dimensional combination projection,the projection distribution of PC1 to PC2 was the best in three kinds of adulteration oil,the projection among different adulteration ratios of peanut oil,rapeseed oil,palm oil and pure tea oil could be clearly distinguished,the greater of adulteration ratio,the better differentiating effects between adulteration samples and pure tea oil were obtained. The differentiating effect order between pure tea oil and three adulteration oil samples was as follows:adulterated peanut oil > adulterated rapeseed oil > adulterated palm oil. The results indicate that this method can be used as a simple and reliable method to identify the adulteration of tea oil.