Quantitation of Crocins and Picrocrocin in Saffron by HPLC: Application to Quality Control and Phytochemical Differentiation from Other Crocus Taxa

Abstract

A chromatographic method was developed and fully validated for the determination of the major saffron constituents, i.e., picrocrocin and five major crocins. Dried samples (styles of Crocus sativus and other Crocus taxa) were extracted with MeOH : water (1 : 1, v/v), and chromatographic separation of the analytes was achieved by reversed-phase chromatography using a gradient elution. Full validation was performed using spiked samples with analytes, which were isolated, purified, and characterized by MS due to a lack of commercial standards. The method showed a good fit (r2 > 0.999) for all analytes with limit of quantitation values in the range of 1-15 µg/mL, and demonstrated adequate intra- and inter-precision (< 15 % RSD) and accuracy (< 7 % RE). The method was applied to the analysis of various commercial saffron samples and of indigenous Crocus taxa and allowed for the first time the absolute quantitation of several Crocus components.