Detecting the Presence of Different Types of Oil in Seawater Using a Fluorometric Index

This study analyzed the fluorometric laboratory tests for the detection of the presence of oil in seawater in cases corresponding to the real situation in the sea: when the point of seawater sampling is not in the same place as the appropriate sensor. The phenomenon of fluorescence exhibited by both natural and alien substances (oil) in the sea was used. The possibility of oil detection in the water column based on a fluorometric index (FI) extracted from the excitation-emission matrix (EEM) was studied. Laboratory tests were carried out on water taken from the Gulf of Gdańsk (Baltic Sea). Seawater samples were contaminated with small amounts of various types of oil (the lowest oil-to-water ratio was 0.5 × 10^-6). A statistically significant difference was found between FI values for uncontaminated seawater and seawater exposed to various kinds of oil (i.e., crude oils, lubricant oils, and fuels).