Application of Cu-based metal-organic framework (Cu-BDC) as a sorbent for dispersive solid-phase extraction of gallic acid from orange juice samples using HPLC-UV method

In the current work, the Cu-based metal-organic framework (MOF) (Cu-BDC) was synthesized through a simple and one-pot solvothermal method and used as a sorbent for dispersive solid-phase extraction (DSPE) of gallic acid (GA) from orange juice samples followed by high-performance liquid chromatography-ultraviolet (HPLC-UV) determination. The prepared Cu-BDC was fully characterized using different analysis including Fourier-transform infrared spectroscopy (FT-IR), X-ray Powder Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDS) and Brunauer-Emmett-Teller (BET). The prepared Cu-BDC had exceptional properties in terms of high specific surface area (400 m2 g−1) and high adsorption capacity (300 mg g−1) toward GA. The influence of effective factors on extraction recovery of GA such as sorbent dosage, ultrasonic time, washing solvent volume and eluent solvent volume was evaluated using a central composite design (CCD) based response surface methodology (RSM). Under the optimized conditions, the presented method showed a wide linear range of 0.5–15.0 mg L−1 with a detection limit of (0.145 mg L−1) and acceptable repeatability (RSD < 6.0%) which shows the applicability of the proposed method for accurate determination of GA from complicated orange juice samples.