Fuel forensics: Recent advancements in profiling of adulterated fuels by ATR-FTIR spectroscopy and chemometric...

Gasoline and diesel are the main petroleum products used for road transportation in India. Due to this reason, adulteration can be done by fraudsters using different miscible substances such as kerosene, turpentine, thinner, ethanol etc. In this work, Fourier transform infrared spectroscopy (FTIR) coupled with principal component analysis (PCA) and partial least square regression (PLSR) were used to investigate adulteration in petroleum products and to design an adulterant profiling. ATR-FTIR has an advantage over other traditional methods as it is less time-consuming and needs no extraction procedure. The samples used for the study were prepared by adding different volume of adulterant (0-20%) to standard diesel and gasoline samples. According to the results obtained from this study, ATR-FTIR spectroscopy proved to be the most comprehensible method for the detection of adulteration in diesel and gasoline fuels. Furthermore, the use of FTIR spectroscopy combined with PCA got best segregation of adulterated samples. The predictive model achieved a root mean square error of prediction of 0.477% and 0.592% for diesel and gasoline respectively.