ZIF-8-Based Solid-Phase Extraction Coupled With Derivative UV-Vis Spectrophotometry for Rapid Simultaneous Determination of Hesperidin and Naringin in Citrus Peels

Abstract

In this study, a rapid and highly sensitive analytical method was developed for the simultaneous extraction and quantification of hesperidin (HES) and naringin (NAR) from citrus peels, effectively valorizing agro-food industrial waste. For the first time, ZIF-8 was employed as a specialized sorbent in solid-phase extraction (SPE), followed by quantification using first-derivative UV-Vis. spectrophotometry. Response surface methodology (RSM) with a central composite design was utilized to optimize the extraction process by evaluating key variables. The successfully synthesized ZIF-8 adsorbent was rigorously characterized via FT-IR, XRD, and SEM. The optimal parameters were identified as a sample and an eluent pH of 7.0, and a sample volume of 1.13 mL. Furthermore, achieving the highest extraction for NAR required 47.50 mg of the adsorbent and 1.63 mL of pure methanol as the eluent, whereas HES required 82.49 mg of the adsorbent and 2.68 mL of the eluent. The proposed method demonstrated excellent sensitivity with a linear range of 2–50 μg/mL and low detection limits of ~0.7 μg/mL. Validation with real citrus peel samples yielded excellent recoveries ranging from 88.0% to 94.0%. In conclusion, this simple and low-cost platform offers an alternative to laborious chromatographic techniques for the quality control of natural compounds.