Forensic Evaluation of Petrol Adulteration via ATR-FTIR Spectroscopy and Chemometric Analysis

Introduction: Gasoline adulteration is a widespread problem that threatens environmental sustainability and public health and affects economic stability. The objective of this study was to forensically detect petrol adulteration using ATR-FTIR spectroscopy combined with chemometric analysis and to evaluate the impact of common adulterants on fuel quality and emissions. Methods: The study utilized ATR-FTIR spectroscopy to examine petrol samples adulterated with kerosene, diesel, turpentine oil, and used cooking oil at various concentrations. Spectral data were collected to identify molecular signatures, and chemometric analysis, specifically Principal Component Analysis (PCA), was employed to classify and differentiate between pure and adulterated samples. Results: Attenuated Total Reflectance Fourier-Transform Infrared (ATR-FTIR) spectroscopy identified distinct characteristic peaks for each adulterant, confirming their presence and unique molecular compositions. Principal Component Analysis (PCA) effectively differentiated between pure and adulterated petrol samples, with the first principal component accounting for over 93% of the variance. This result underscores the high accuracy and reliability of this method. Discussion: These findings highlight the effectiveness of integrating spectroscopic and chemometric techniques to detect fuel adulteration. This study also emphasizes the broader implications of adulteration, including increased emissions, engine damage, and economic losses, reinforcing the need for robust forensic detection methods. Conclusion: This study demonstrates that ATR-FTIR, when combined with chemometric analysis, is a precise and reliable method for detecting petroleum adulteration. It also proposes a standardized forensic protocol and emphasizes the significance of interdisciplinary strategies in addressing fuel-related crimes and safeguarding environmental and public health.