拉曼光谱-聚类分析法快速鉴别掺伪花生油

目的建立快速鉴别掺伪花生油的拉曼光谱.聚类分析方法。方法以不同产地、不同品牌的多批次花生油、大豆油、玉米油、菜籽油、葵花籽油、精炼棕榈油、精炼棉籽油及精炼地沟油为样品,在780 nm和532 nm激光光源下,扫描和比较其普通、扩展及导数拉曼光谱的形态。结果在532 nm激光光源的扩展光谱及一阶导数光谱中,花生油与低价植物油及精炼地沟油光谱的信息量最大,样品间光谱形态的差异显著,谱峰得到有效分离。基于此全波段光谱信息和形态建立的多步聚类分析模型及鉴别程序对36份不同花生油、105份不同低价植物油、30份仿冒花生油和38份不同精炼地沟油的判别正确率均为100%,对180份5%及以上的掺假花生油的判别正确率达86%以上,对75份5%及以上的掺杂花生油的判别正确率为92%,对72份5%及以上的掺杂植物油的判别正确率达92%以上。样品测量时无需制备样品及消耗化学试剂,测量和分析一份样品仅耗时5 min左右。结论所建立的拉曼光谱.聚类分析模型既可准确鉴定花生油,还可准确鉴定各种类型的掺伪花生油,可实现对掺伪花生油的快速、无损和准确鉴别。

Rapid detection of adulterated peanut oil by Raman spectrum-cluster analysis

Raman spectrum-cluster analysis was developed for rapid detection of adulterated peanut oil based on the multiple batches of peanut oil, soybean oil, corn oil, rape seed oil, sunflower seed oil, palm oil, cotton seed oil and refined bio-waste oil with varius producing locations and brands. Under the excitation of 532nm laser, the extended and first-derivative Raman spectrum showed the largest spectral information and significantly different patterns among peanut oil, low-price vegetable oil and bio-waste oil. The cluster analysis model established on full-range spectrum information would identify peanut oil as well as kinds of adulterated peanut oil. The discriminant rate was 100% for 36 peanut oil, 105 low-price vegetable oils, 30 fake peanut oil and 38 refined bio-waste oils. The discriminant rates were 86%, 92% and 92% respectively, for 180 peanut oil mixed with at least 5% low-price vegetable oil, 75 peanut oil mixed with at least 5% bio-waste oil, and 72 vegetable oils mixed with at least 5% bio-waste oil. The measurement process required no sample preparation or chemical reagent consumption, and the time cost was 5min for each sample, therefore the detection for adulterated olive oil was rapid, non-destructive and accurate.