THE DETECTION OF ADULTERATED GASOLINE: A BRIEF REVIEW OF THE MAIN ANALYTICAL METHODS

Abstract

Introduction:
Gasoline adulteration means loss of tax revenue, mechanical damage to cars and harmful effects on health and environment. Existing analytical methods allow
adulterants presence to be detected.
Objective:
The objective of this review is to provide a quick and general overview of these methods, comparing their advantages and disadvantages, which allow defining the ideal scope for each of them.
Materials and Methods:
The literature reviewed shows that analytical options can be classified into three categories. Physicochemical parameters include density, viscosity, octane number, Reid vapor pressure and distillation curve. Chromatographic methods include high performance liquid chromatography and gas chromatography, while spectroscopic
methods include fluorescence spectroscopy, infrared spectroscopy and proton nuclear magnetic resonance spectroscopy.
Results and Discussion:
The physicochemical parameters may have a low sensitivity and they are insufficient to detect adulterations. Chromatographic methods require time, but they need very little sample and can reveal adulterant nature. Spectroscopic methods are fast, sensitive, although 1H-NMR spectroscopy has high instrumentation cost.
Conclusions:
Gas chromatography is suitable for those hardest to detect adulterations. In contrast, spectroscopic methods are more appropriate for processing a large number of samples. 1H-NMR is a very valid option, although FTIR spectroscopy is a much cheaper option. In countries with limited economic resources, physical-chemical methods may be the most appropriate option.