Detection and quantification of virgin argan oil adulteration using benchtop and portable Raman spectrophotometers: A comparative study

This study evaluated three Raman instruments (benchtop Senterra II, portable Rigaku, and portable MIRA XTR), with different laser wavelengths, for detecting and quantifying argan oil adulteration. The data analysis followed a tiered chemometric approach: first employing Principal Component Analysis for preliminary data exploration and visualization, then applying Partial Least Squares-Discriminant Analysis (PLS-DA) to distinguish authentic from adulterated samples and to identify specific adulterants, and finally developing Partial Least Squares Regression (PLSR) models to precisely estimate adulteration levels. The PLS-DA models enabled the identification of the adulterant, while the PLSR models successfully quantified adulterant levels down to 5 % with high accuracy. Comparative analysis revealed that all instruments were effective for screening purposes, with the portable MIRA XTR demonstrating a somewhat superior performance in both classification accuracy and quantification precision. To our knowledge, this is the first direct comparison of benchtop and portable Raman instruments for the qualitative and quantitative analysis of argan oil.