Evaluation of gasoline fuel quality using FTIR spectroscopy and multivariate technique: a case study in Aizawl city

Abstract

Fuel quality control had become increasingly important due to the direct relationship between fuel quality and vehicle emissions. Variability of gasoline fuel from one refilling station to another is analyze using Fourier Transform Infrared spectroscopy (FTIR) and Principal Component Analysis (PCA). The result indicates that HC chain length, oxygenate, toluene and aromatic content are the major variables that cause sample variation and grouping. Determination of kerosene and Methyl tert-Butyl Ether (MTBE) concentration in gasoline fuel is done by using partial least squares (PLS) regression multivariate technique as applied to FTIR-ATR spectral data of the test samples. PLS calibration models were developed for the prediction of kerosene and MTBE and validated with independent set of known samples. Accordingly, among 179 tested samples, 103 samples contain kerosene (% v/v) less than 10%, 61 samples contain 11–20%, 11 samples contain 21–30% and 4 samples exceed 30% resulting that majority of gasoline fuel in the study area are adulterated. It is observed that 17 samples are MTBE blended with varying concentrations in the range of 1–7.34% v/v. This study provides an inexpensive and effective method to investigate gasoline quality, detection of adulterants and oxygenator in areas where adulteration of fuel is quite popular.