tailieunhanh - Drugs and Poisons in Humans - A Handbook of Practical Analysis (Part 61)

Introduction: Among many carbamate pesticides commercially available in Japan, those with relatively high toxicities are shown in Table [1]. Carbamate pesticides are generally classified into N-methylcarbamate insecticides and N-allylcarbamate herbicides in view of their chemical structures and biological actions. The number of fatalities due to poisoning by carbamate pesticides is 50–100 every year in Japan; many of them are poisoned by methomyl [2]. According to statics reported by National Research Institute of Police Science of Japan, the number of fatalities is highest with paraquat plus diquat, followed by organophosphates and then carbamates among pesticides. . | Carbamate pesticides by Kiyoshi Ameno Introduction Among many carbamate pesticides commercially available in Japan those with relatively high toxicities are shown in Table 1 . Carbamate pesticides are generally classified into N-methylcarbamate insecticides and N-allylcarbamate herbicides in view of their chemical structures and biological actions. The number of fatalities due to poisoning by carbamate pesticides is 50-100 every year in Japan many of them are poisoned by methomyl 2 . According to statics reported by National Research Institute of Police Science of Japan the number of fatalities is highest with paraquat plus diquat followed by organophosphates and then carbamates among pesticides. The toxicity of carbamate pesticides is due to inhibition of acetylcholinesterase AchE by their binding with the active site of the enzyme the inhibition of the hydrolysis reaction of acetylcholine Ach results in the accumulation of Ach provoking poisoning symptoms such as miosis lacrimation sweating hypersalivation and convulsion of extremities. The binding of carbamate pesticides to AchE is much weaker than that of organophosphorus pesticides and the former pesticides are easily decomposed in mammalian bodies. Therefore the damages of organs by carbamate pesticides have not been reported. For analysis of carbamate pesticides methods by GC 3-7 GC MS 5 7 8-10 HPLC 11 and LC MS 10 were reported. In this chapter the extraction procedures and analytical methods using the above 4 instruments are described for this group of pesticides. Reagents and their preparation The authentic standards of compounds listed in Table and ethion can be purchased from Wako Pure Chemical Industries Ltd. Osaka Japan. A standard mixture of seven N-methylcarbamate pesticides can be obtained from Kanto Chemicals Tokyo Japan b. Carbofuran carbaryl and ethion are separately dissolved in acetone to prepare 100 pg mL solutions as stock solutions for internal standards ISs c. .