Magnetic Sorbent with a Mesoporous Shell for the Simultaneous Preconcentration of Ecotoxicants of Different Nature

Resumo

A magnetic sorbent with a multilayer shell of the composition Fe₃O₄@TEOS@CTAB@TEOS + MPTEOS designed for the simultaneous or sequential preconcentration of components of various nature is obtained. The conditions of microwave synthesis and modification of a new magnetic sorption material are described; its composition and particle sizes are characterized. The sorption capacity of the sorbent is provided by creating a mesoporous silica layer filled with cetyltrimethylammonium bromide (CTAB) micelles and additionally modified with an S-containing polymer (MPTEOS) on the surface of the magnetic carrier. The properties of the obtained material with respect to the regulated substances from two groups of priority pollutants are studied: phenols of various structures and heavy metals. The main sorption characteristics (effect of pH, phase contact time, nature of eluent, V: m, salt background) are studied and the conditions for extracting ecotoxicants at their concentration in the solution at a level of μg/L are optimized. The data obtained under the conditions of separate and simultaneous extraction of analytes of different nature confirmed a possibility of the quantitative determination of various types of natural water pollutants at the levels significantly lower than the MPC using a single sorption material. In using HPLC methods and electrothermal atomic absorption spectrometry, a complete analysis of a single sample takes 40−50 min and of a series of samples, 2–3 h. Such characteristics, combined with the simplicity of material preparation make it promising for routine analytical studies.