Development of Dispersive Micro-Solid-Phase Extraction Method using Carbon-Based Adsorbent for Determination of Dexamethasone in Sport Supplements

Abstract

Introduction: Due to the increasing use of supplements for various purposes as well as the spread of fraud in this area, regulators also need newer and more accurate methods to investigate these products. These supplements can be used in various fields and include types and amounts of unauthorized substances. Objective: To develop an accurate, fast and low-cost method for detecting and measuring fraud in a variety of supplements and optimizing this method for high efficiency. Methods: In the first stage, the dexamethasone chromatographic separation method was optimized and launched; The parameters studied at this stage included the selection of the mobile phase, the mobile phase Flow Rate, and the adjustment of the appropriate λmax for dexamethasone. In the next step, after synthesis of graphene oxide-diethylamine adsorbent (GO-DEA), the extraction method was optimized, which included adjusting the type of adsorbent, the amount of nanosorbent used, setting the adsorption and desorption time and selecting the appropriate solvent for the desorption step. Results: In order to draw the calibration diagram, standard dexamethasone solutions were prepared by optimized solid-state solid phase microextraction method and the linear range was plotted at 3.125-50 μg / ml. The accuracy of the method was less than 10% and its accuracy was reported in the range of 5%. In order to evaluate the application of the method, ten additional samples of perfumers in Tabriz were purchased and examined. Discussion and Conclusion: Purification and concentration of real samples were performed within 4 minutes using 6 mg of GO-DEA adsorbent. The results of the study showed that 4 out of 10 cases were infected with dexamethasone. The present results will inspire further development of sample preparation methods using carbon-based adsorbents to monitor food quality.