Molecularly imprinted silica as a selective SPE sorbent for triazine herbicides

Abstract

A molecularly imprinted organically modified silica was prepared through a simple sol-gel procedure and evaluated as a specific sorbent for SPE of triazine herbicides. The material proved to be highly selective for the template molecule, atrazine, as well as for other structurally related species such as simazine and propazine. The performance of this material was shown to be comparable with commercial acrylate-based molecularly imprinted polymers. The molecularly imprinted silica was applied for the determination of trace levels of the target triazine analytes in sugar cane juice (locally called "garapa").

Solid‐phase extraction using octadecyl‐bonded silica modified with photosynthetic pigments from Spinacia oleracea L. for the preconcentration of lead(II) ions from aqueous samples

“…The affinity of the solid‐phase sorbent to an analyte depends on the type of the sorbent and ligands immobilized on its surface. Small organic molecules as the targeted analytes can be effectively isolated using molecularly imprinted polymers , magnetic dummy molecularly imprinted nanoparticles as the suitable sorbents in SPE , graphene‐based sorbents , and electrospun nanofibers . Effective SPE sorbents have been also developed for preconcentration/isolation of trace metal ions from aqueous systems.…”

On‐line solid‐phase extraction for liquid chromatography–mass spectrometry analysis of pesticides

“…Figure shows the general SPE process that basically consists in four different steps: (a) the solid sorbent is wetted by an appropriate solvent in order to activate the functional groups on its surface (conditioning step); (b) sample is percolated through the sorbent (loading step); (c) clean‐up by washing the sorbent with a solvent of low elution strength to eliminate matrix components that have been retained on the solid sorbent (washing step); and (d) elution of analytes of interest by employing an appropriate solvent with a higher elution strength (elution step). Off‐line SPE methodology has been extensively used to extract pesticides and, despite the fact that today there is a general trend toward on‐line methods, it is probably still the most widely used configuration in sample preparation for environmental and food analysis in general . Off‐line SPE approach remains a useful technique for analyzing pesticides in complex matrices, because of its greater flexibility and whenever elution solvent is not compatible with the subsequent method of analysis .…”

Atrazine: cytotoxicity, oxidative stress, apoptosis, testicular effects and chemopreventive Interventions

“…ATZ can be found in the environment at concentrations as substantial as 21 ppb in groundwater, 42 ppb in surface waters, 102 ppb in water basins in farm areas, and up to 224 ppb in streams ( Kolpin et al, 1998 ; Owagboriaye et al, 2022 ; Roh et al, 2023 ). The U.S. Environmental Protection Agency (EPA) has set the maximal limit of ATZ allowed in drinking water (MCL) at 3 ppb and has designated ATZ as a Restricted Use Pesticide in an attempt to minimize human exposure to ATZ through drinking contaminated groundwater ( Costa Silva et al, 2010 ; Powell et al, 2011 ). However, in occupational set-up, humans are exposed to ATZ at a thousand-fold higher concentration than seen in residential exposure.…”