Abstract
Different surfactant-modified solid sorbents have been comparatively investigated for retention of carbamate pesticides in aqueous solution. Three modified-sorbents, including sodium dodecyl sulfate (SDS) treated alumina, cetyltrimethyl ammonium bromide (CTAB) coated silica and CTAB coated zeolite, were created using different surfactant concentrations. The studied carbamate pesticides including oxamyl, methomyl, aldicarb, carbofuran, carbaryl, isoprocarb, methiocarb, promecarb and carbosulfan were analyzed by HPLC/UV. Adsorption of all carbamate pesticides (concentration range between 0.5-5.0 mg L-1) onto surfactant-modified sorbents followed linear regressions with the correlation coefficients in the range of 0.857-0.995. CTAB-modified zeolite showed high uptake values for carbofuran, carbaryl, methiocarb and carbosulfan. SDS-modified alumina demonstrated high uptake values for carbaryl, isoprocarb, methiocarb, promecarb and carbosulfan. CTAB-modified silica gave high uptake values for methiocarb, promecarb and carbosulfan. Desorption of carbamate pesticides from surfactant-modified sorbents using methanol were better than that obtained from unmodified sorbents. The study clearly proved that the surfactant-modified sorbents are effective for carbamate pesticides extraction.
Highlights
Carbamates are one of the major persistent organic pesticides widely used in agriculture to protect a variety of crops
The major bands of both surfactants appeared at 3467‐2871 cm−1, while the Fourier transform infrared spectroscopy (FT-IR) spectra of all modified sorbents were different from raw support materials (Figure 2)
For some of studied pesticides (i.e, OXM, MTM, ADC and CBF sorbed on sodium dodecyl sulfate (SDS)-alumina, CBF and MTC sorbed on Cetyltrimethyl ammonium bromide (CTAB) silica, MTM and IPC sorbed on CTAB-zeolite), an enlargement of adsorbed amounts was observed when the surfactant concentration loaded onto the solid sorbents was increased
Summary
Carbamates are one of the major persistent organic pesticides widely used in agriculture to protect a variety of crops. Inorganic solid supports, which normally are used as sorbent materials, including silica, alumina and zeolite, were modified with surfactants to improve their sorption capability for organic compounds.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
