Preconcentration and determination of ranitidine hydrochloride in real samples by using modified magnetic iron oxide nanoparticles

This method shows a novel, fast, and simple magnetic solid-phase extraction (SPE) and spectrophotometric procedure for preconcentration and determination of ranitidine hydrochloride in human plasma and aquatic samples by using Fe₃O₄ nanoparticles (NPs) modified by sodium dodecyl sulfate (SDS) as an extractor. The unique properties of Fe₃O₄ NPs including high surface area and strong magnetism were utilized effectively in the magnetic SPE process. The determination method is based on the SDS-coated Fe₃O₄ NPs with extracted ranitidine-HCl, which was subsequently monitored spectrophotometrically at λ_max = 320 nm. Effects of different parameters influencing the extraction efficiency of ranitidine-HCl including the pH value, amount of SDS, and Fe₃O₄ NPs, extraction time, desorption solvent, desorption time, and sample volume were optimized. Under optimized conditions, the method was successfully applied to the extraction of ranitidine-HCl from human plasma and aquatic samples. The extraction recovery in human plasma and different matrixes of waters were investigated and values of 89.0%- 103.4% were obtained. The calibration graph for the determination of ranitidine-HCl was linear in the range of 0.025-1.50 μg mL^-1 with R² = 0.9946. The limit of detection of the proposed method was 7.5 x 10^-3 μg mL^-1. The repeatability and reproducibility (relative standard deviation) of the mentioned method were 0.83% and 1.22%, respectively. The experimental results showed that the proposed method was feasible for the analysis of ranitidine-HCl in environmental and biological samples. (author)