Extraction of pesticide residues from plant extracts using regenerative MCM41 mesoporous materials

摘要

The aim of the current study was to determinate the adsorption degree of pesticide residues on MCM41 mesoporous material from plant extracts usually used in phytotherapeutic treatments. The choice of the material was based on the high adsorption capacity, due to the specific surface area, over 800 m2/g and for the possibility of their regeneration/ reusability capacity. The silica matrix was synthesized starting from tetraethylorthosilicate (TEOS)- the silica source and hexadecyltrimethylammonium bromide (CTAB)- as a template agent, the whole process taking place in continuous flow at room temperature and normal pressure. The material obtained was characterized by microscopy techniques (transmission and scanning electron microscopy TEM and SEM) for determination of pores morphology, by standard method Brunauer-Emmett-Teller for pore size distribution and specific surface area (textural analysis- B.E.T), by Fourier-transform infrared spectroscopy (FTIR) for spectral fingerprint and by dynamic light scattering (DLS) for determination of hydrodynamic diameter of particles. The tests were carried out on extracts performed with organic solvents from some medicinal species (Menthae officinalis, Salvia officinalis, Matricaria chamomilla), using mesoporous material MCM41 for isolation / concentration of pesticide residues. Quantitation of pesticide residues was performed using a gas chromatograph coupled with a triple quadrupole mass spectrometer (GC-MS/MS), for both extracts and MCM41 material.