Rapid ultrasound-assisted magnetic microextraction of gallic acid from urine, plasma and water samples by HKUST-1-MOF-Fe 3 O 4 -GA-MIP-NPs: UV-vis detection and optimization study.

Magnetite (Fe3 O4 nanoparticles (NPs)) HKUST-1 metal organic framework (MOF) composite as a support was used for surface imprinting of gallic acid imprinted polymer (HKUST-1-MOF-Fe3 O4 -GA-MIP) using vinyltrimethoxysilane (VTMOS) as the cross-linker. Subsequently, HKUST-1-MOF-Fe3 O4 -NPs-GA-MIP characterized by FT-IR, XRD and FE-SEM analysis and applied for fast and selective and sensitive ultrasound assisted dispersive magnetic solid phase microextraction of gallic acid (GA) by UV-Vis (UA-DMSPME-UV-Vis) detection method. Plackett-Burman design (PBD) and central composite design (CCD) according to desirability function (DF) indicate the significant variables among the extraction factors vortex (mixing) time (min), sonication time (min), temperature (°C), eluent volume (L), pH and HKUST-1-MOF-Fe3 O4 -NPs-GA-MIP mass (mg) and their contribution on the response. Optimum conditions and values correspond to pH, HKUST-1-MOF-Fe3 O4 -NPs-GA-MIP mass, sonication time and the eluent volume were set as follow 3.0, 1.6mg, 4.0min and 180μL, respectively. The average recovery (ER%) of GA was 98.13% with desirability of 0.997, while the present method has best operational performance like wide linear range 8-6000ngmL-1 with a Limit of detection (LOD) of 1.377ngmL-1 , limit of quantification (LOQ) 4.591ngmL-1 and precision (<3.50% RSD). The recovery of GA in urine, human plasma and water samples within the range of 92.3-100.6% that strongly support high applicability of present method for real samples analysis, which candidate this method as promise for further application.