title: Colorimetric determination of methyl parathion and oxygen analog.
abstract: A simple, sensitive, and rapid colorimetric method is described for determining methyl parathion (O,O-dimethyl-O-p-nitrophenyl phosphorothioate) and methyl paraoxon (O,O-dimethyl-O-p-nitrophenyl phosphate), using p-nitrobenzene diazonium fluoroborate as the chromogenic salt. This colorimetric method is more sensitive than are other colorimetric methods based on non-enzymatic reactions. Pig liver acetone powder cholinesterase was found to be sensitive to methyl parathion. Inhibition can be detected at picogram levels, and 50-80 ng methyl paraoxon and 1-9 micrograms methyl parathion can be estimated.
mesh_terms: D000818:Animals; D002800:Cholinesterase Inhibitors / Q000032:analysis; D003124:Colorimetry; D007306:Insecticides / Q000032:analysis*; D008099:Liver / Q000201:enzymology; D008743:Methyl Parathion / Q000032:analysis*; D010261:Paraoxon / Q000031:analogs & derivatives* / Q000032:analysis; D010278:Parathion / Q000031:analogs & derivatives*; D013552:Swine; D014908:Triticum / Q000032:analysis
chemical_list: D002800:Cholinesterase Inhibitors; D007306:Insecticides; D008743:Methyl Parathion; D010278:Parathion; D010261:Paraoxon; C008480:methylparaoxon