应用气相色谱和同步荧光光谱鉴别溢油

Combination of Gas Chromatography and Synchronous Fluorescence Spectroscopy to Identify Spilled Oils

运用气相色谱法和同步荧光法分别测定了7个原油样品(其中2个油品来源相同)和一种润滑油的饱和烃色谱和同步荧光光谱,分析了正构烷烃组分包含姥鲛烷(2,6,10,14-四甲基十五烷,Pr)和植烷(2,6,10,14-四甲基十六烷,Ph)的分布特征,及反映油品中多环芳烃等荧光性组分的荧光光谱特征.谱图分析结果显示:润滑油的色谱图和同步荧光光谱图与原油的明显不同,易与原油油品区分开;渤海海区的2种原油Y1与Y2较为特殊,饱和烃含量低,根据色谱即可鉴出;南海4个油品中Y6饱和烃的含量较低,采用色谱能与另外3个样品分开,结合同步荧光光谱可将Y5与Y3,Y4分开;来源相同的Y3和Y4的荧光光谱基本一致,差别仅在于Y4在C23前的正构烷烃(含姥鲛烷和植烷)含量均略低于Y3,而C23之后的正构烷烃均略高于Y3,其因为Y4发生了轻度风化.将油品的正构烷烃特征和同步荧光光谱特征一起用聚类分析和主成分分析处理,结果显示:7个油品中5个油样可以明显区分开;Y3和Y4距离很近.研究表明:将气相色谱和同步荧光光谱所体现的油品的正构烷烃(含姥鲛烷和植烷)和多环芳烃特征一起作为油品的指纹信息,应用常见的化学计量学方法,即可方便鉴别油样.

Seven oil samples, two of which from the same producing area, were chosen and analyzed by gas chromatography with a flame ionization detector （GC-FID） and synchronous scanning fluorescence spectroscopy （SFS）. The distribution of n-alkane components including pristane （Pr） and phytane （Ph） were also analyzed. Fluorescence spectra representing characteristics of PAHs and other fluorescent components were determined. The lubricating oil had significantly different chromatogram profile from crude oil samples and could be easily identified; two oil samples, Y1 and Y2 contained very low saturated hydrocarbons, thus could be easily differentiated from the other crude oil samples; As for four South China Sea crude oil samples, Y6 had lower saturated hydrocarbons and could be identified using gas chromatography; Y3, Y4 and Y5 had similar chromatograms, but combined with SFS, Y5 could be identified; Y3 and Y4 had almost identical SFS, with Y4 having slightly lower n-alkanes before Cz3 and slightly higher n-alkanes after C23, due to weathering. Combination of n-alkanes concentrations and SFS data between 260 nm and 460 nm were processed using principal component analysis （PCA） and cluster analysis. Five of the seven oils samples could be identifited; Y3 and Y4 were almost identical. The research indicates that it is feasible using GC-FID together with SFS and applying common chemometrics to match spilled oils from probable sources.