Background:
Herbicides are very beneficial in the crop yield with the aid of controlling
weeds within the agriculture, but several herbicides are chronic in soil.
Objective:
In this study, nanoparticles and the packages of synthesized novel silica nanoparticles
were studied for the preconcentration of herbicides.
Methods:
These nanoparticles prepared by the Stöber mechanism were purified and functionalized.
Nanoparticles thus prepared successfully were used as supporting material for the preconcentration
of residues of herbicides in the water.
Results:
Preconcentration was achieved by preparing the silica-based solid-phase-extraction cartridges.
Nanoparticles used for this purpose were within the range of 50-250 nm. An SPE cartridge
was prepared by packing 200 mg of silica nanoparticle in the empty cartridge of diameter 5.5 cm and
length 0.6 cm in between PTFE frits. Aqueous solutions of 0.1 μg/ml of herbicides were prepared
separately, and 10 ml of the solution was passed through the cartridge at the rate of 0.2 ml/min. After
passing 10 ml volume of the aqueous solution, residues adsorbed on the cartridge were eluted using 2
ml of acetonitrile. The eluate was injected to determine the herbicide residue adsorbed on the SPE
cartridge.
Conclusion:
In the study, it was found that greater than 90% of the herbicide residues were trapped
on silica nanoparticle-based SPE cartridge. An analytical method was developed for the simultaneous
determination of these herbicides. The residues were quantified by LC-MS/MS with ESI mode.
Structure determination of methyl esters of unsaturated fatty acids by gas-liquid chromatography of the aldehydes formed by triphenyl phosphine reduction of the ozonides