核桃油中掺大豆油的同步荧光光谱快速鉴别(英文)

Rapid Quantitative Determination of Walnut Oil Adulteration with Soybean Oil by Synchronous Fluorescence Spectroscopy

展示了同步荧光光谱法在核桃油掺大豆油鉴别以及同步荧光法结合多元分析对掺假核桃油进行评价方面的应用潜力.获得同步荧光光谱的激发波长范围为250～700 nm,波长间隔范围为10～100 nm.核桃油和大豆油的等值同步荧光光谱相比较,发现在激发波长低于275 nm范围内,核桃油具有特殊的荧光谱图.研究过程使用了51个以不同比例大豆油掺假的核桃油混合样品,采用偏最小二乘法分别对波长间隔为20、40、80 nm的同步荧光谱图数据进行回归,实现对核桃油掺假情况的定量分析.本研究可以在2.5 min内实现对核桃油掺大豆油比例在0.6%以上的样品进行快速检测.

In this paper, the potential of using total synchronous fluorescence （TSyF） spectra to differentiate walnut oil from soybean oil and synchronous fluorescence （SyF） spectra combined with multivariate analysis to assess the adulteration of walnut oil is demonstrated. TSyF spectra are acquired by varying the excitation wavelength in the region 250 - 700 nm and the wavelength interval （ AA ） in the region from 10 to 100 nm. TSyF contour plots for walnut oil, in contrast to soybean oil, show an extra fluorescence region in the excitation wavelength lower than 275 nm. Fifty one oil mixtures are prepared by adulterating walnut oil with soybean oil at varying levels. The partial least - squares regression model is used for quantification of the adulteration using wavelength intervals of 20, 40 and 80 nm. This technique is useful for detection of soybean oil in walnut oil at levels down to 0.6% （v/v） in just 2.5 minutes.