Magnetic solid-phase extraction based on fluconazole-functionalized Fe₃O₄@SiO₂ nanoparticles for the spectrophotometric determination of cationic dyes in environmental water samples

Abstract

In the present study, a novel method based on fluconazole-functionalized magnetic silica nanoparticles as the adsorbent is introduced for the extraction of malachite green and crystal violet. The synthesized nanoparticles were characterized using SEM, EDX, XRD, FT-IR, and BET methods. The adsorbent were added to the sample solution containing 100.0 ng mL⁻¹ of each dye (pH 5.0); then, the mixture was agitated at room temperature for 20.0 min. The supernatant was poured, and then, the isolated nanoparticles were eluted with methanol to desorb the adsorbed dyes. Different parameters were investigated and optimized to achieve effective extraction and preconcentration of the target dyes. Limits of detection and limits of quantification for malachite green and crystal violet under optimum conditions changed in the range of 2.82–3.27 ng mL⁻¹ and 9.42–10.91 ng mL⁻¹, respectively. Preconcentration factor and relative standard deviation for five repetitions of each dye were computed to be 188 and 4.77–4.17%, respectively. Finally, the mentioned dyes were extracted and determined using the proposed method from environmental aqueous samples. The recoveries range for malachite green and crystal violet were in 88–96%.