Switchable solvent-based liquid microextraction in combination with magnetic solid microextraction for determination of vitamin B۹ (folate or folic acid)

A novel and environmentally friendly method has been developed for the extraction and quantification of folic acid (vitamin B۹) in pharmaceutical formulations. The method integrates switchable hydrophilicity solvent-based liquid-liquid microextraction (SHS-LLME) with magnetic solid-phase microextraction (MSPE) to achieve high extraction efficiency and analytical sensitivity. N, N-dimethylcyclohexylamine (DMCA) was employed as the switchable solvent, taking advantage of its reversible polarity under acid-base conditions. Surface-modified Fe₃O₄ magnetic nanoparticles, functionalized with oleic acid, were synthesized and used as magnetic sorbents to enhance dispersion, adsorption efficiency, and magnetic recovery. Key experimental parameters were optimized, including solvent and modifier volumes, extraction temperature, sorbent mass, and desorption conditions. Nanoparticle characterization was performed using FTIR, XRD, FESEM, TEM, and VSM analyses, confirming their structure, morphology, and superparamagnetic properties. UV-Vis spectrophotometry was used for final quantification. The method demonstrated excellent linearity over the range of ۲.۵–۲۵ mg/L (R² = ۰.۹۹۹۶), with a limit of detection (LOD) of ۰.۱۲۷ mg/L and a limit of quantification (LOQ) of ۰.۳۸۴ mg/L. This approach offers several advantages, including low solvent consumption, rapid processing, and enhanced recovery, making it a reliable and sustainable tool for pharmaceutical analysis and quality control applications.

کلیدواژه ها:

Folic acid ، Oleic acid ، MSPE ، Switchable solvent-based liquid microextraction ، Nanoparticles