基于傅立叶变换红外光谱1120cm^(-1)～1097cm^(-1)波段吸收峰差异鉴别地沟油

Identification of trench oils based on the absorption peak difference in the range of 1120 cm^(-1)～1097 cm^(-1) by Fourier transform infrared spectroscopy

目的基于傅立叶变换红外光谱1120 cm-1~1097 cm-1波段吸收峰差异鉴别地沟油,为植物油市场监管提供技术支持。方法收集市售所有12个品种食用植物油76份,地沟油毛油36份,并按照脱臭、脱色、脱酸工艺炼制不同精炼程度的精炼地沟油26份,采集各类油脂样品的傅立叶变换中红外吸收光谱,通过比较分析各类样品1120 cm-1~1097 cm-1波段吸收峰差异,评估此处吸收峰对鉴别"地沟油"与食用植物油的有效性。结果除茶籽油和橄榄油之外的10种食用植物油在1120 cm-1~1097 cm-1范围内峰形相似,分别在1119cm-1附近和1098 cm-1附近出现的2个小峰,并呈现"小大峰",而所有地沟油毛油及3种精炼程度不同的精炼地沟油在相应峰位出现的2个小峰与食用植物油相比峰高出现逆转,呈现"大小峰"。结论基于傅立叶变换红外光谱1120 cm-1~1097 cm-1波段吸收峰差异可辅助鉴别地沟油与多种食用植物油。

Objective To identify trench oils from edible vegetable oils by Fourier transform infrared spectroscopy （ FITR）, and provide technology support for market supervision of vegetable oils. Methods A total of 138 oils including 76 edible vege- table oils of 12 kinds, 36 bio - waste crude oils and 26 refined trench oils were collected to analyze the absorption peaks differ- ence in the range of 1120 cm- 1 - 1097 cm- 1 by FITR, in order to evaluate the effectiveness of absorption peak in discriminating different oils. Results Except the tea - seed oil and olive oil, the absorption peaks of the other 10 kinds of edible vegetable oils were similar in the range of 1120 cm -1 - 1097 cm-l. There were 2 small peaks near 1119 cm-l and 1098 cm-1 , showing ＂small - big peaks＂. While the two absorption peaks in the corresponding peak position of all the bio - waste crude oils and three refined trench oils reversed, showing ＂big - small peaks＂. Conclusion The method based on the absorption peak differ- ence in the range of 1120 cm-1 -1097 cm-1 by FITR can effectively identify trench oils from many kinds of edible vegetable oils.