Novel Spectroscopic Method for Determination and Quantification of Saffron Adulteration

In this study, a spectroscopic method was developed for the determination and quantification of saffron adulteration with some plant adulterants (safflower, marigold, and turmeric). For this purpose, three spectroscopic techniques, namely, attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, Raman spectroscopy, and laser-induced breakdown spectroscopy (LIBS), were applied, and the superiority of the techniques was investigated by using principal component analysis (PCA). All spectral data were compared, and the best discrimination among saffron and plant adulterants was obtained with LIBS according to PCA results. Following this analysis, partial least squares (PLS) method was carried out using LIBS data to reveal the level of plant adulteration in saffron samples. A good linearity was obtained with a coefficient of determination (R2) values of 0.999 for calibration and cross-validation in the range of 10–50% with a limit of detection (LOD) and quantification (LOQ) of 1.86 and 9.32%, respectively. Taking the results into consideration, it was seen that the LIBS technique combined with PLS provides a sensitive determination of plant adulterants in saffron under 10%, which is difficult to detect using the reference UV-Vis spectroscopic method.