FTIR Spectroscopy for Direct Asphaltene Quantification in Argentine Crude Oils

Abstract Asphaltenes have long been the subject of extensive research due to their complex structures, variable chemical composition, and strong tendency to aggregate, which is a major cause of pipeline clogging, leading to significant economic losses. In this study, both conventional and unconventional crude oil samples from local production fields in Argentina were analyzed using Fourier Transform Infrared Spectroscopy (FTIR), while density and asphaltene content were determined following standard methods. FTIR spectra analysis identified key signals within the 600–900 cm–1 region (812, 699, and 722 cm–1). Both univariate and partial least-squares (PLS) regression models showed strong linear correlations between infrared absorption and asphaltene content (R2 = 0.92 and 0.99, respectively). The multivariate model achieved robust predictive performance (Q2 = 0.96; RMSECV = 0.14 wt %; corrected RMSECVx = 0.4 wt %). These preliminary, encouraging results demonstrate that FTIR is a potentially rapid and cost-effective tool for asphaltene quantification, warranting further evaluation.