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A novel type of carbon nanotube-coated Au nanoparticle and [bmim]BF4 composite modified glassy carbon electrode was fabricated by a layer-by-layer self-assembly technique. The electrochemical performance of acetaminophen (ACOP) on the modified electrode was investigated by cyclic voltammetry. The Nafion/GNPs/RTIL/MWNTs/GC electrode showed an excellent electrocatalytic activity for the oxidation of ACOP and accelerated electron transfer between the electrode and ACOP. For ACOP, the reversible electrochemical process was observed on the Nafion/GNPs/RTIL/MWNTs/GC electrode, while irreversible electrochemical process occurred on the GC electrode. For the Nafion/GNPs/RTIL/MWNTs/GC electrode, the anodic peak potential of ACOP was moved from 0.562 V to 0.413 V, with a potential drop of 149 mV. At the same time, the reduction peak potential was 0.384 V, and the potential difference was only 29 mV. It was shown that the modified electrode possessed higher electrocatalytic activity and more sensitive effect for the detection of ACOP than both MWNTs/GC electrode and GC electrode. The effects of the different experimental conditions on the electrochemical behaviors of ACOP were explored. Under the optimum conditions of preparation and experimental, the linear calibration curves of ACOP were obtained in a wide range of 2 x 10(-1) to 4.0 x 10(-4) mol x L(-1) with a correlation coefficient 0.999 2 and a detection limit of 2.6 x 10(-8) mol x L(-1) (the ratio of signal to noise, 3:1). The recovery rate was 97.9%-100.8%. This method can be used to determine ACOP in paracetamol tablets with satisfactory results.
Acetaminophen ; analysis ; Analgesics, Non-Narcotic ; analysis ; Antipyretics ; analysis ; Electrochemical Techniques ; methods ; Electrochemistry ; methods ; Electrodes ; Electron Transport ; Gold ; chemistry ; Nanotubes, Carbon ; chemistry ; Oxidation-Reduction ; Reproducibility of Results

6.Surveillance of coal-burning endemic fluorosis prevailing status in Henan Province

Bo, YU ; Yang, LIU ; Chun-sheng, YUAN ; Jian-shan NG KA ; He-qiu NG HUA ; Jian-jun, WEI ; Liu-an, HU ; Ai-ru, LI

Chinese Journal of Endemiology 2009;28(2):191-193

Objective To understand the prevailing status of coal-burning endemic fluorosis in Henan, and to provide scientific grounds for endemic fluorosis prevention. Methods Undertook general surveillance on factors such as coal using, living habit, main foods, the structure of the houses and the fluoride content in drinking-water among 1832 historical coal-burning endemic fluorosis villages within 13 counties in 2006 and 2007, and conducted focal point sampling survey on 216 villages which still using local high-fluoride. For all children aged 8-12 years of each village, conducted dental fluorosis examination and collected 30 immediate urinary samples for fluoride content determination. Results The fluoride content in drinking-water of all historical fluorosis villages was below 1.0 mg/L. Households having individual kitchens accounted for 93.7%(241 281/257 393), those with stoves having smoke evacuation devices accounted for 41.9% (107 917/257 393), those using local high-fluoride coal for cooking accounted for 28.6%(73 686/257 393), those using local high-fluoride coal for heating accounted for 24.1%(61 924/257 393). Villages with serf-supply of main foods accounted for 95.7%(1753/1832) of all fluorosis villages. Solar drying food was used in all households. Villages with dental fluorosis detection rate for children aged 8 to 12 years above 30.0% accounted for 16.2%(35/216), which axe all in Luoyang City. Among 77.8%(168/216) of fluorosis villages, children' s urinary fluoride concentrations were no higher than 1.50 mg/L. Conclusions Coal-burning endemic fluorosis areas in Henan Province were decreased greatly and the extent of the health hazard was becoming slightly. The detection rate of dental fluorosis for children aged 8 to 12 years of 8 counties had reached the standard for fluorosis control, whereas the other 5 counties had not yet, all located in Luoyang City.