Chromatographic Methods Developed for the Quantification of Quercetin Extracted from Natural Sources: Systematic Review of Published Studies from 2018 to 2022.

Quercetin (QUE) is the most widely used flavonoid for therapeutic purposes. To improve the available knowledge about the properties of some natural products, determining the amount of QUE is crucial. The main objective of this systematic review is to identify the analytical methods validated for detecting and quantifying QUE in different matrices and characterize their sensitivity. A search was conducted until 30 June 2023 in the PubMed database for experimental studies that addressed the validation of chromatographic analytical methods to detect and quantify QUE from consumable natural products. Only studies published between 2018 and 2022, written in English, were included. The risk of bias was assessed by emphasizing methods of comparison according to previously published studies. Descriptive statistics were used to depict the obtained results. The studies were analyzed based on the type of QUE source, chromatographic method, and validation parameters. A total of 17 studies were included in this review. Plants were the most commonly analyzed source of QUE. Among the detection methods, spectrophotometry proved to be the most widely used, surpassing mass spectrometry (MS). After analyzing the bias, all the included studies mentioned/presented, totally or partially, at least four of the eight parameters.