Trace papaverine analysis in biological samples after preconcentration by UA-D-μ-SPE method using a new magnetic GO–MOF nanocomposite

The present contribution describes the synthesis of a novel, green, and cost-effective UA-D-μ-SPE (ultrasound-assisted dispersive micro-solid phase extraction) method employing a magnetic graphene oxide/metal-organic framework (GO/MOF) nanocomposite as a sorbent for specific preconcentration of papaverine from complex biological media. The GO/MOF nanocomposite synthesized by design possesses highly well-defined structure by FT-IR, FE-SEM, XRD, EDS, VSM, and BET studies, which proved to exhibit an ample specific surface area, enhanced sorption capacity, high chemical and thermal stability, rapid adsorption rate, and high reusability. The magnetic nature ensures easy separation without centrifugation, and thus the process of extraction is efficient and easy to run. Optimization of the key extraction parameters was regularly carried out with central composite design (CCD) in order to achieve an efficient operation with the least consumption of resources in keeping with green analytical chemistry. The method is of very good analytical performance with a LOD and LOQ of 0.09 ng mL^-1 and 0.3 ng mL^-1, respectively, with intra- and inter-day precision of 3.3% and 4.7% at 10 ng mL^-1. Application to biological samples resulted in good recoveries (95.24-98.08%), even from intricate matrices. The novel UA-D-μ-SPE technique, coupled with HPLC-UV detection, not only yields enhanced sensitivity, selectivity, and environmental sustainability but also reduces sample preparation time and operational cost significantly. Incorporation of state-of-the-art nanocomposite sorbents and comprehensive optimization emphasizes the method's potential as a reliable tool for trace-level pharmaceutical analysis in biomedical and clinical research.