Crude oil UV spectroscopy and light scattering characterization

Crude oil is a complex mixture of hydrocarbons representing several classes of compounds. Some of these constituents significantly affect refinery processes and analysis procedures. Ultraviolet-visible (UV-vis) spectroscopy has received wide acceptance because of its broad scope, given that many active species in the spectrum of UV, and many more that with proper treatment, are able to form visible species in that spectrum. In this study two crude oils from different sources were analyzed without dilution C1-RC, in the coastal region and C2-RM of the maritime region of the Gulf of Mexico. Stages for obtaining calibration curves depending on the change in concentration of crude, starting from crude standard solutions and evaluating the repeatability of the method and the dispersion, were established. The results show three signals: (a) 230 nm corresponding to benzene compounds, (b) 260 nm to naphthenic compounds, and (c) 410 nm Soret band corresponding to the metal porphyrins. These species are found in asphaltenes, signals were evaluated individually for separate calibration curves, at concentrations between 10 and 90 mg L^?1. The model equation of each curve based on the absorbance and concentration determination coefficient values for each compound are reported. It was possible to establish that the method developed is suitable for oil solutions at low concentrations.