Over the past decade,neonicotinoid insecticides have become the fastest-growing and most widely used class of pesticides.Initially,these compounds were considered ideal replacements for more hazardous chemicals such a...Over the past decade,neonicotinoid insecticides have become the fastest-growing and most widely used class of pesticides.Initially,these compounds were considered ideal replacements for more hazardous chemicals such as carbamates and organophosphates,due to their presumed limited impact on the environment and human health.However,neonicotinoids have since been detected in soils,surface waters,groundwater,food,and various human biological samples.Moreover,they have been shown to negatively affect aquatic organisms,including aquatic insects,crustaceans,mollusks,fish,algae/macrophytes,and amphibians.Epidemiological studies and human biomonitoring research have revealed both acute and chronic health effects,ranging from respiratory,cardiovascular,and neurological symptoms to congenital abnormalities.This review examines the effects of neonicotinoids,their ecological consequences,and the potential risks associated with human exposure.展开更多
This paper reports on the development of a novel electrochemical assay for cadmium (II) in natural water, which involves the use of disposable hydroxyapatite modified platinum electrode (HAP/Pt). Cadmium (II) was prec...This paper reports on the development of a novel electrochemical assay for cadmium (II) in natural water, which involves the use of disposable hydroxyapatite modified platinum electrode (HAP/Pt). Cadmium (II) was preconcentrated on the surface of the modified electrode and adsorbed onto HAP and oxidized at E = –680 mV. The HAP-modified platinum electrode exhibited superior performance in comparison to the plati- num electrode and surprisingly, yielded a higher electrochemical response. The best defined anodic peak was obtained with 0.2 mol L-1 KNO3 pH 5.0 after 25 min of accumulation time. Using these conditions, the cali- bration plot was linear over the range 1 × 10?8 to 5 × 10?6 mol L-1 Cd2+. The precision was examined by car- rying out eight replicate measurements at a concentration of 2.5 ×10?5 mol L-1;the coefficient of variation was 2.9%. The method was applied to the determination of the analyte in river water samples. The interfere- ence of other metal ions on the voltammetric response of Cd(II) was studied. The HAP films was clearly ob- served in the SEM images and characterized by X-ray diffraction, IR spectroscopy and chemical analysis.展开更多
文摘Over the past decade,neonicotinoid insecticides have become the fastest-growing and most widely used class of pesticides.Initially,these compounds were considered ideal replacements for more hazardous chemicals such as carbamates and organophosphates,due to their presumed limited impact on the environment and human health.However,neonicotinoids have since been detected in soils,surface waters,groundwater,food,and various human biological samples.Moreover,they have been shown to negatively affect aquatic organisms,including aquatic insects,crustaceans,mollusks,fish,algae/macrophytes,and amphibians.Epidemiological studies and human biomonitoring research have revealed both acute and chronic health effects,ranging from respiratory,cardiovascular,and neurological symptoms to congenital abnormalities.This review examines the effects of neonicotinoids,their ecological consequences,and the potential risks associated with human exposure.
文摘This paper reports on the development of a novel electrochemical assay for cadmium (II) in natural water, which involves the use of disposable hydroxyapatite modified platinum electrode (HAP/Pt). Cadmium (II) was preconcentrated on the surface of the modified electrode and adsorbed onto HAP and oxidized at E = –680 mV. The HAP-modified platinum electrode exhibited superior performance in comparison to the plati- num electrode and surprisingly, yielded a higher electrochemical response. The best defined anodic peak was obtained with 0.2 mol L-1 KNO3 pH 5.0 after 25 min of accumulation time. Using these conditions, the cali- bration plot was linear over the range 1 × 10?8 to 5 × 10?6 mol L-1 Cd2+. The precision was examined by car- rying out eight replicate measurements at a concentration of 2.5 ×10?5 mol L-1;the coefficient of variation was 2.9%. The method was applied to the determination of the analyte in river water samples. The interfere- ence of other metal ions on the voltammetric response of Cd(II) was studied. The HAP films was clearly ob- served in the SEM images and characterized by X-ray diffraction, IR spectroscopy and chemical analysis.
