Dissolved/dispersed hydrocarbons in seawater, determined by infrared and fluorescence spectroscopy

Abstract

Samples of sub-surface (1m) and surface water were collected in the harbour of Las Palmas. These have been analyzed by infrared and by fluorescence spectroscopy in order to provide information on the levels of hydrocarbons generally present in the area. With the infrared method, the absorbance at 2925cm−1 has been measured and the values are given as API mixture equivalents. For the determination of total hydrocarbons by fluorescence spectroscopy, both the single-wavelength excitation fluorescence spectra which were used for the determination of the total concentration and the synchronous excitation spectra which give more structural information were recorded. The concentrations are given as chrysene equivalents. In all cases, high concentration levels of oil were detected. The results obtained from the two methods have been explained based upon the meteorological and oceanographic conditions.