5 research outputs found
Retention of Carbamate Pesticides by Different Surfactant-Modified Sorbents: a Comparative Study
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
Vortex-Assisted Dispersive Micro-Solid Phase Extraction Using CTAB-Modified Zeolite NaY Sorbent Coupled with HPLC for the Determination of Carbamate Insecticides
Selective Uptake and Bioaccumulation of Antidepressants in Fish from Effluent-Impacted Niagara River
The
continuous release of pharmaceuticals and personal care products (PPCPs)
into freshwater systems impacts the health of aquatic organisms. This
study evaluates the concentrations and bioaccumulation of PPCPs and
the selective uptake of antidepressants in fish from the Niagara River,
which connects two of the North American Great lakes (Erie and Ontario).
The Niagara River receives PPCPs from different wastewater treatment
plants (WWTPs) situated along the river and Lake Erie. Of the 22 targeted
PPCPs, 11 were found at part-per-billion levels in WWTP effluents
and at part-per-trillion levels in river water samples. The major
pollutants observed were the antidepressants (citalopram, paroxetine,
sertraline, venlafaxine, and bupropion, and their metabolites norfluoxetine
and norsertraline) and the antihistamine diphenhydramine. These PPCPs
accumulate in various fish organs, with norsertraline exhibiting the
highest bioaccumulation factor (up to about 3000) in the liver of
rudd (<i>Scardinius erythrophthalmus</i>), which is an invasive
species to the Great Lakes. The antidepressants were selectively taken
up by various fish species at different trophic levels, and were further
metabolized once inside the organism. The highest bioaccumulation
was found in the brain, followed by liver, muscle, and gonads, and
can be attributed to direct exposure to WWTP effluent