地沟油拉曼光谱特征形态

Morphological feature of bio-waste oil in Raman spectrum

目的寻找鉴别地沟油与食用植物油的拉曼光谱特征谱带。方法比较和分析地沟油与食用植物油拉曼光谱的形态及差异。结果在532 nm光源普通及扩展光谱中,精炼地沟油呈现平滑包状拉曼谱带,各种类型及来源不同的地沟油普遍具有与之形态相似的拉曼谱带,而各种食用植物油无一具有这一形态的拉曼谱带。通过导数扩展光谱可以有效分离精炼地沟油与食用植物油之间原本严重重叠的谱峰,而通过导数普通光谱可以测量和描述掺杂植物油中地沟油的掺入量。结论平滑包状拉曼谱带是普遍见于地沟油的指纹图谱。该指纹图谱可为鉴别地沟油与植物油,以及检测油脂样品中地沟油的掺入量提供丰富的信息及适用的标志。

Objective To describe the morphological feature of bio-w aste oil in Raman spectrum for the discrimination of bio-w aste oil from edible vegetable oil. Methods The morphology and difference in Raman spectrum for biow aste oil and edible vegetable oil were compared and analyzed. Results In the full-and extended-range Raman spectra at the wavelength of 532 nm,there was a morphological feature of smooth bulk peak for various bio-w aste oil samples which was not observed in all the samples of edible vegetable oil. The peaks of bio-w aste oil samples in the first-derivative extended-range spectrum could be effectively distinguished form those of edible vegetable oil samples and the difference in the first-derivative full-range spectrum betw een the bio-w aste oil and edible vegetable oil could be used to quantify the amount of adulterated bio-w aste oil in vegetable oil. Conclusion A smooth bulk peak in Raman spectrum exists universally in the detection of various bio-w aste oil samples and could be used in the detection of adulterated biow aste oil in edible vegetable oil.