Polymer Monolith Microextraction Coupled with HPLC for Determination of Jasmonates in Wintersweet Flowers

A simple, fast, and effective method has been presented for the determination of jasmonates in plant samples by polymer monolith microextraction (PMME). A poly (methacrylic acid-ethylene glycol dimethacrylate) (MAA-EGDMA) monolith-based device was developed for extraction, purification, and concentration; HPLC-UV was used for evaluation. To realize the best microextraction efficiency, parameters such as sample pH value, flow rate, and sample volume were systematically examined and optimized. Aqueous solution (5 mL) of jasmonates at pH 3.0 was selected as sample solution, and loaded onto the monolith at flow rate of 0.15 mL/min; finally, 50 mu L of acetonitrile was used for elution. The proposed method exhibited impressive enrichment efficiency (almost 100-fold) and the limits of detection for jasmonic acid and methyl jasmonate obtained 0.5 and 2 ng/mL by using UV detection. Wide linear ranges were also observed (22000 and 52000 ng/mL) for both jasmonic acid and methyl jasmonate, with R2 > 0.999. The developed PMME-HPLC method was successfully applied to the determination of jasmonates in fresh wintersweet flowers with recoveries in the range of 91.997.2%. The result was confirmed by an HPLC-MS method. The PMME method was also compared with a conventional C18-SPE method and exhibited better clean-up efficiency.