Ahmadinouri Fatemeh, Parvin Parviz, Rabbani Ahmad Reza
Department of Energy Engineering and Physics, Amirkabir University of Technology (Tehran Polytechnic), P.O. Box 15875-4413, Tehran, Iran.
Department of Energy Engineering and Physics, Amirkabir University of Technology (Tehran Polytechnic), P.O. Box 15875-4413, Tehran, Iran.
Spectrochim Acta A Mol Biomol Spectrosc. 2024 Jan 5;304:123314. doi: 10.1016/j.saa.2023.123314. Epub 2023 Aug 31.
Crude oil is one of the most significant petrogenic sources of polycyclic aromatic compounds (PACs). These substances play an essential role in the pollution of the marine environment. Therefore, the rapid identification of this pollutant source and its fractions is vital. For this purpose, a fast and on-site method of laser-induced fluorescence spectroscopy based on modified Beer-Lambert (LIFS-MBL) is proposed here using solvent densitometry. Three optical parameters of the self-quenching (K), the extinction (α), and the peak concentration (Cp) are experimentally extracted from MBL graphs. Note that the parameters above are known to be unique characteristics of various crude oils. The corresponding compounds are generally classified into saturate, aromatic, resin, and asphaltene fractions, abbreviated as SARA. Differentiation among these fractions is achieved using the LIFS-MBL method by selecting the optimal excitation wavelength at 405 nm. This line effectively rules out the light aromatic rings and focuses on heavy fractions. The correlation of optical parameters with heavy oil fractions is verified according to analysis of variance. Statistical relations are proposed to calculate crude oil fractions values. The values of light fractions including saturate and aromatic components can also be determined by the heavy fractions. In this method, the test time is notably reduced from four days using the standard methods to less than half an hour according to the presented LIFS-MBL technique.
原油是多环芳烃（PACs）最重要的成岩来源之一。这些物质在海洋环境污染中起着至关重要的作用。因此，快速识别这种污染物来源及其馏分至关重要。为此，本文提出了一种基于改进的比尔-朗伯定律的激光诱导荧光光谱快速现场检测方法（LIFS-MBL），该方法采用溶剂密度测定法。从MBL图中通过实验提取了自猝灭（K）、消光（α）和峰值浓度（Cp）这三个光学参数。需要注意的是，上述参数是各种原油的独特特征。相应的化合物通常分为饱和烃、芳烃、树脂和沥青质馏分，简称为SARA。通过在405nm处选择最佳激发波长，利用LIFS-MBL方法实现了这些馏分之间的区分。这条谱线有效地排除了轻质芳香环，专注于重质馏分。根据方差分析验证了光学参数与重油馏分之间的相关性。提出了统计关系来计算原油馏分的值。轻质馏分（包括饱和烃和芳烃成分）的值也可以由重质馏分确定。在该方法中，根据所提出的LIFS-MBL技术，测试时间从使用标准方法的四天显著减少到不到半小时。
