A molecularly imprinted organic-inorganic hybrid monolithic column for the selective extraction and HPLC determination of isoprocarb residues in rice

Abstract

An IPC-imprinted (IPC is isoprocarb) poly(methacrylic acid)/SiO2 hybrid monolithic column was prepared and applied for the recognition of the template. The hybrid monolithic column was synthesized in a micropipette tip using methyltrimethoxysilane as the inorganic precursor, 3-(methacryloxy)propyltrimethoxysilane as the coupling agent, and ethylene glycol dimethacrylate as the cross-linker. The synthesis conditions, including the porogenic solvent, coupling agent, volume ratio of the inorganic alcoholysate and organic part, were optimized. The prepared monolithic column was characterized by SEM and FTIR spectroscopy. A simple, rapid, and sensitive method for the determination of IPC in rice using the imprinted monolithic column microextraction combined with HPLC was developed. Several parameters affecting the sample pretreatment were investigated, including the eluent, washing solution, and loading sample volume. The linearity of the calibration curve was observed in the range of 9.0-1000 μg/kg for IPC in rice with the correlation coefficient (r2) of 0.9983. The LOD was 3.0 μg/kg (S/N = 3). The assay gave recovery values ranging from 91 to 107%. The proposed method has been successfully applied for the selective extraction and sensitive determination of IPC in rice and a satisfactory result was obtained.

Advances in the development and applications of organic–silica hybrid monoliths

“…In addition, MPTMS serves to anchor MIP to the inner wall of the capillary. In some instances inorganic precursors such as TEOS or MTMS are used in addition to MPTMS. However, an aqueous acid catalyst is needed in these cases.…”

“…However, an aqueous acid catalyst is needed in these cases. Organic–silica hybrid MIP monoliths were prepared with various template molecules such as ractopamine , enrofloxacin , isoprocarb , 2,4‐dichlorophenoxyacetic acid , caffeine , 4‐(dimethoxyphpsphorothioylamino)butanoic acid , zolmitriptan , and trichlorfon , and were afterward used for separation of four isomers of ractopamine , detection of fluoroquinolone residues in milk (recovery range 89.1–99.2%) , extraction of isoprocarb (91–107%) or 2,4‐dichlorophenoxyacetic acid (80–94%) residues from rice, and caffeine from milk (85–104%) , selective recognition of acephate and phosphamidon in vegetables (79.7–94.4%) , chiral separation of ( R )/( S )‐zolmitriptan , and detection of trichlorfon in vegetables (80.2–95.8%) .…”

Recent Advances and Uses of Monolithic Columns for the Analysis of Residues and Contaminants in Food

“…A common limit for most of these fibers is their fragility, but in this case, the MIP fiber proved to be firm and stable. A relatively new approach is the preparation of MIP monoliths inside a pipette tip and matched to a syringe for performing the polymer monolith microextraction [6,37,40,46,51]. Pipette tip-based molecularly-imprinted polymer monolith microextraction (PT-MIPMME) has been used for the selective extraction of sulfamethoxazole in milk, achieving high recoveries and low standard deviations [40].…”

Preparation of an acryloyl β‐cyclodextrin‐silica hybrid monolithic column and its application in pipette tip solid‐phase extraction and HPLC analysis of methyl parathion and fenthion

“…Therefore, organic polymer monolithic columns with various functional groups have been widely prepared and applied for separation in sample pretreatment and HPLC. However, the swelling of the organic polymer monolithic column in organic solvents leads to a short lifetime and unsatisfactory stability . To combine the merits of both silica‐based and organic polymer monoliths, such as good mechanical stability and ease of preparation, the organic–inorganic hybrid monolithic column was developed and has been attracting more attention in recent years .…”