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EN
The main task for natural marine environment protection is to prevent the inflow of various contaminants including oil substances and the real challenge is the ability to rapidly detect these pollutants. Moreover important is to find the source or the maker of the oil spill. In this paper, we consider fundamental physical aspects in the area of possibility of monitoring the natural marine ecosystem based on fluorescence spectroscopy. We utilize the fluorescence ability of numerous oil components – mainly polycyclic hydrocarbons. The paper concerns the spectrofluorimetric characterization of oils have been in use during exploitation of the marine fleet, i.e. lubricate oil, fuels, transformer and hydraulic oils as well as crude oils or their residues. Every kind of oil has a chance to enter the marine environment, especially in a case of ship emergency or after collision with other vessel ore shoreline structure as well as when ship enters the stranding. After discharge of oil, some of oil components are dissolved in the water, bacteria or photochemical reactions, which results in transformation of composition of oil, degrade some. Fluorescence spectrometer Perkin Elmer LS55 was applied to obtain the fluorescence spectra using different excitation wavelength in the range from 240 nm to 500 nm. We discuss the changes of the shapes of excitationemission spectra (EEMs) of various types of oil and the EEMs spectra after contact of oil with seawater as an oil-inwater emulsion, which is the most frequent form of oil in the water column. Significant changes in the shape of spectra and displacement of the peaks are observed.
EN
The present development of a basic science, including physics of stimulated emission of light, opens up new diagnostic possibilities in relation to the quality of oils, including marine fuels and lubricants. In complicated chemical composition of oils both light absorbing compounds and compounds that emit light (fluorescent) are included. This causes the formation of complex structures in the spectral plots of fluorescence intensity as a function of wavelength of light exciting fluorescence and as a function of the wavelength of light emitted. Since the fluorescence excitation occurs in a short time of its disappearance. The shape of the fluorescence decay function depends on the chemical composition of oil, therefore, includes a mention of its kind, quality, level of degradation, and the like. In this paper exemplary charts of the intensity decay curves in different parts of the fluorescence spectra are shown (for light fuel). Presented charts are obtained using the experimental device constructed in Bremerhaven University of Applied Sciences (Germany) and are the attempt to use ability of oil substance to manifest its composition in the form of the fluorescence decay curve. An analysis of the chart shows that decay of fluorescence in this case is described by biexponential curve, therefore a kind of oil can be represented by two numerical values - two decay time constants. Operational use of this method will be possible only after a comparative study of different types and quality of oil in relation to the shape of the fluorescence decay curves.
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