IN-VITRO ADSORPTION OF DICHLORVOS AND PARATHION BY ACTIVATED-CHARCOAL

Accidental and suicidal ingestions of organophosphate compounds contin ue to be a common occurrence in Turkey. Activated charcoal administrat ion without gastric emptying has been advocated as primary therapy in most acute poisoning cases, although some references do not recommend activated charcoal use in organophosphate poisoning. This study was pe rformed to determine the in vitro adsorption of dimethyl dichlorovinyl phosphate (dichlorvos) and parathion by activated charcoal over a wid e range of charcoal:organophosphate ratios (1:1, 2.5:1, 5:1, 10:1 and 20:1, g:g). The charcoal binding ability of dichlorvos and parathion w ere studied in both pH 1.2 and pH 7 environments. The supernatant was extracted with n-hexane and then analyzed by gas chromatography. Each incremental increase in charcoal dose increased the percent adsorption of dichlorvos and parathion. At the 20:1 ratio, 82.8 +/- 2.0 / 87.3 /- 2.9 % (pH 1.2/7.0) of dichlorvos and 59.3 +/- 4.5 / 64.5 +/- 6.1 % (pH 1.2/7.0) of parathion were bound by activated charcoal. There were no significant differences in amounts of compound bound in the acid a nd neutral solutions. Large doses of activated charcoal effectively bi nd dichlorvos and parathion in vitro. In vivo research should be perfo rmed to determine activated charcoal's role in organophosphate poisoni ng cases.