Measuring of water and soil contamination with oil components using laser-induced fluorescence transmitted through optical fibers

Abstract

A summary of the fluorescence properties of several types of crude oils is done. Data about excitation and fluorescence spectra of Diesel oil and kerosene are introduced. An experimental arrangement conceived to measure laser induced fluorescence for crude oil and oil components in water and soil is reported, containing a nitrogen pulsed laser as light source for fluorescence excitation and optical fibers to send to the sample the excitation signal and, respectively, to collect the fluorescence radiation. Fluorescence spectra in the visible, of Romanian crude oil, Diesel oil and kerosene, in water and soil, obtained with the developed set-up, are reported. Fluorescence lifetimes for Romanian crude oil, Diesel oil and kerosene in liquid samples are measured, obtaining 9.5 nsec for `East Swan' crude oil, 19 nsec for Diesel oil and 11.5 nsec for kerosene, considering laser time pulse delay through the collecting optical fiber less than 0.1 nsec. Concluding remarks about fluorescence spectral and temporal properties are made, in connection with monitoring requirements for crude oil and oil components in soil and water.