海上溢油油膜厚度的定量检测是实现溢油量准确估计的重要依据和手段, 为制定石油污染应急响应提供了基础数据。 本文基于激光诱导荧光(LIF)的方法以柴油(0# diesel)、 机油(Mobil motor oil 20w-40)、 润滑油(Shell Helix 15w-40, Shell Helix 10w-40, Shell Helix 5w-40)为研究对象, 重点分析了油膜厚度-荧光发射强度关系, 检出限以及油膜厚度在不同水体中定量检测的准确性。 结果表明: 0#柴油和美孚机油20w-60的荧光光谱特征与润滑油的光谱特征有明显不同, 柴油的荧光峰位于326 nm其FWHM为60 nm, 美孚机油20w-60则具有三个荧光峰分别位于360 nm/375 nm/390 nm其FWHM为100nm。 三种润滑油(壳牌润滑油15w-40、 壳牌润滑油10w-40、 壳牌润滑油5w-40)的荧光光谱重叠明显, 荧光峰分别位于334, 344和343 nm且FWHM分别为75, 45和50 nm。 5种油膜的荧光强度均随油膜厚度的增加而增加, 校正曲线的相关性分别为0.997 8, 0.997 9, 0.996 4, 0.997 8和0.996 0, 均具有较好的相关性, 5种油膜检出限分别为0.03, 0.02, 0.02, 0.03和0.05 μm, 0#柴油在合成海水A和B中的平均相对误差为5.04%和8.73%, 平均相对标准偏差分别为4.37%和8.36%, 美孚机油20w-40在合成海水A和B中的平均相对误差为7.99%和9.97%, 平均相对标准偏差为4.78%和6.23%。 壳牌润滑油15w-40在合成海水A和B中的平均相对误差为8.54%和13.69%, 相对标准偏差为5.05%和9.08%。 壳牌润滑油10w-40在合成海水A和B中的平均相对误差为6.33%和12.38%, 平均相对标准偏差为2.85%和7.92%。 壳牌润滑油5w-40在合成海水A和B中的平均相对误差为4.28%和11.57%, 平均相对标准偏差为3.56%和7.73%。 可见5种油膜在不同水体中定量检测的平均相对误差均小于14%, 平均相对标准偏差均小于10%, 研究结果可以实现对薄油膜的测量, 为海上油膜厚度的在线监测提供了技术手段。

Quantitative detection of oil slick thickness in the ocean is an essential basis to achieve an accurate estimate of oil spills and provides primary data for the development of oil pollution emergency response. In this paper, we use diesel(0# diesel), motor oil (Mobil motor oil 20w-40), Lubricants (Shell Helix 15w-40, Shell Helix 10w-40, Shell Helix 5w-40) as the research objects, using laser-induced fluorescence (LIF) obtains the spectra of materials. The oil film thickness-fluorescence intensity calibration curves are established, and the detection limits of five kinds of oils are calculated. The accuracy of the quantitative detection of different oil film thicknesses in different water is analyzed. The results show that the fluorescence spectra of 0# diesel and Mobil motor oil 20w-40 are significantly different from those lubricants. The fluorescence peak of diesel is at 326 nm, and its FWHM is 60 nm. Mobil motor oil 20w-40 has three fluorescence peaks at 360 nm/375 nm/390 nm, and the FWHM is about 100 nm. The fluorescence spectra of the three lubricants (such as Shell Helix 15w-40, Shell Helix 10w-40, Shell Helix 5w-40) overlap significantly, and the fluorescence peaks are located at 334, 344, and 343 nm, respectively. With the increase of oil slick thickness, the fluorescence intensity of the five kinds of oil films is rising. The calibration curves of oil slicks have good correlation, and the correlation coefficients(r) are 0.997 8, 0.997 9, 0.996 4, 0.997 8, and 0.996 0, respectively. The detection limits are 0.03, 0.02, 0.02, 0.03 and 0.05 μm. It can be seen that the average relative errors of quantitative detection of five kinds of oil films in different water are less than 14%, and the average relative standard deviations are not greater than 10%. The results can be used to measure thin oil films and provide a technical means for on-line monitoring of oil film thickness at sea.