Light absorption properties of ‘Petrobaltic’ oil-in-water emulsion present in seawater

In the article, the characteristic of crude oil ‘Petrobaltic’ potentially present in the Baltic Sea water masses is considered in relation to the protection of marine environment. The main spectroscopic method to characterize various oils (crudes and refinery products like fuels and lubricating oils) is fluorescence. However, the absorbance measurements of oils are necessary due to the partial overlapping the spectra of natural seawater components and oil substances. Therefore, properties of crude oil are considered to expand the basis of spectroscopic properties of oils – typical marine organic pollutants – based on absorption measurements. Oils potentially found in the marine environment are, in addition to surface forms, also in-depth ones as oil-in-water emulsion. Therefore, in the article crude oil as oil-in-water emulsion form is considered. As a solvent demineralised water with salinity, corresponding to Baltic Sea salinity was used. Several concentrations of dispersed crude oil were prepared. The absorbance spectra in the UV and visual range of the light in the range from 240 to 600 nm, for each prepared samples are discussed. Based on the Lambert-Beer law for each wavelength of excitation, in the range 240-600 nm, the specific parameter absorption coefficient was determined. Obtained results indicate the rapid decreasing of the absorbance for this kind of oil in the wavelength range from 240 nm to 420 nm. However, in the shape of absorbance spectra is observed the characteristic wide and flat peak located at 260 nm for excitation wavelength, which could be a specific point for this kind of oil.

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Opracowanie rekordu w ramach umowy 509/P-DUN/2018 ze środków MNiSW przeznaczonych na działalność upowszechniającą naukę (2018).