Caramelized carbonaceous shell-coated γ-Fe2O3 as a magnetic solid-phase extraction sorbent for LC-MS/MS analysis of triphenylmethane dyes.

Abstract

Carbonaceous shell-coated γ-Fe2O3 nanoparticles (γ-Fe2O3@CNM) were synthesized from glucose caramelization and used as a novel magnetic solid-phase extraction medium for malachite green and crystal violet in environmental water. Malachite green and crystal violet were absorbed on to γ-Fe2O3@CNM by electrostatic and π-interactions. The morphologies, pore structures, surface functional groups, and magnetic properties of γ-Fe2O3@CNM were characterized by TEM, FTIR, hysteresis regression, Brunauer-Emmet-Teller analysis, zeta potential, XPS, and XRD. The magnetic solid-phase extraction procedure was optimized by extraction pH, absorption time, desorption solvent, and desorption time. The absorption capacities (qmax values) for malachite green and crystal violet were 34.2 and 27.9mgg-1, respectively. After magnetic solid-phase extraction, malachite green and crystal violet were determinedby LC-MS/MS. The analytical method was validated with alinear range of0.02-20ngmL-1, enrichment factor of25.8 and 25.4, method detection limit of0.004ngmL-1, and intra-day precisions of2.1% and 2.6% for malachite green and crystal violet, respectively. The relative recovery was found to be 73.4-101.5% for malachite green and 83.1-102.7% for crystal violet upon the application of the magnetic solid-phase extraction method to real water samples from lake, spring, sea, fishpond, and industrial waste. Graphical abstract Caramelized-carbon-coated magnetic nanoparticles are used as novel extraction medium based on electrostatic and π-interactions. It is porous, amphiphilic, electronegative, magnetically strong, and features abundant absorption site. These characteristics stimulate mass transfer and result in a useful MSPE method in environmental analysis.