A rapid high-performance liquid chromatographic method for the determination of sinapine and sinapic acid in Canola seed and meal

A high-performance liquid chromatographic (HPLC) method has been developed to separate sinapine and sinapic acid from other phenolics in canola seed a nd meal in a single run. The separation was achieved with a reverse-phase C 18 column. Owing to the higher recovery of phenolics and ease of use, reflu xing with 100% methanol for 20 min was selected as the extraction method fo r HPLC analysis and determination of total phenolics using Folin-Ciocalteu reagent. A 10-min isocratic/linear/concave gradient and a 15-min isocratic/ linear gradient were selected as the best gradients for the separation of these phenolic compounds. Peak identities for sinapine and sinapic acid wer e verified with ion exchange separation followed by HPLC analysis. The meth od was calibrated using sinapine bisulfate and sinapic acid standards; corr elation coefficients (R-2) for the calibration curves were 0.997 and 0.999 for sinapine bisulfate and sinapic acid, respectively. The extinction coeff icient of sinapine was determined to be 1.16 times that of sinapic acid at the detector wavelength (330 nm). Applying this method to routine canola ph enolic analyses can greatly reduce the cost by simplifying the procedures a nd reducing the time required for each determination.