Determination of petroleum hydrocarbons in aqueous matrices using infrared spectroscopy

Abstract

Total petroleum hydrocarbons are among the most important water pollutants; they may be present in storage systems and underground and surface supply sources due to leaks, spills, dumping and / or poor waste management that these organic compounds contain. The objective of this work is to develop an analytical procedure to quantify hydrocarbons in aqueous matrices using mid-range infrared spectroscopy and tetrachloroethylene as an extraction solvent. The transmission technique was used in 30 mm thick quartz cells and the maximum height measurement in 2930 cm-1 corresponding to the asymmetric C-H stretching vibration of methylenes was performed. The mean calibration error and the limit of quantification were equal to 0,0002 mg / ml. Recoveries of 77 and 84% were obtained for concentration levels 0,2640 and 0,5280 mg/l, respectively. The global error in the concentrations was 0,0001 mg/l and the relative standard deviations were less than 5%. The proposed procedure is suitable for the intended purpose in the concentration range of. 0,0002 to 0,0819 mg / ml.