Extraction of bioactive coumarins from lime peel as sample pretreatment before chromatographic analysis

Abstract Analysis of lime peel was applied to assess their suitability for various intended purposes, e.g., application in perfumery, cosmetics, and cleaning products, or as a source of bioactive or other value-added compounds. Targeted analysis allows wider usability of the waste part of these natural materials. In the present study, a novel, efficient, lab-simple, time-saving analytical method for coumarins determination in lime peel, including sample pretreatment by extraction and quantification by HPLC with fluorescence detection (FLD), is introduced. Optimal conditions of ultrasound assisted extraction included water as extraction solvent, temperature of 40 °C, and extraction time of 10 min. A magnetic molecularly imprinted polymer was employed as solid phase extraction adsorbent for primary extract cleaning, isolation, and enrichment of coumarins before chromatographic analysis. Recovery of herniarin and umbelliferone was more than 86 % ((RSD ≤ 4.8 %). Linear range of 50—1000 ng/mL with correlation coefficient above 0.998 was obtained for the proposed HPLC-FLD method. The limit of quantification was 8.2 and 44 ng/mL for herniarin and umbelliferone, respectively. These results show that the proposed sample pretreatment procedure is suitable for analytical purposes and is perspective also for the analysis of other citrus samples, as well as for future scale-up preparative isolation of bioactive coumarins from citrus peel.