We describe here fatal levels of paraquat in plasma of victims due to the ingestion of the herbicide, paraquat, and the relationship between those levels and survival times after ingestion. We determined paraquat levels in plasma of 106 paraquat poisoning cases in Korea between June 1992 and December 1996 using a visible spectrophotometric method based on the alkali-dithionite reaction. Among 55 cases with known survival times, plasma paraquat levels of victims who died within one day of ingestion ranged from 2.3 to 636.6 microg/ml (average 127.6 microg/ml) while those of the victims who died between 1 approximately 4 days ranged from 0.9 to 25.1 microg/ml (average 7.0 microg/ml). Since preparations containing 24.5% paraquat dichloride are still used in Korea, our data for Korean victims who died within one day were 8.5 times higher than those in Baselt and Cravey's report for the same survival times. Our data also suggest that victims in whom a plasma paraquat concentration of more than 30 microg/ml was detected are likely to have died within 24 h after ingestion.

We describe here three cases involving acute fatalities due to benfuracarb ingestion and the forensic toxicological implications. Benfuracarb, a carbamate insecticide and its main metabolite carbofuran, were detected using thin layer chromatography (TLC) and gas chromatography/mass spectrophotometry (GC/MS) after extraction with ethyl acetate and then quantified using gas chromatography (GC) equipped with NPD. The blood levels of benfuracarb and carbofuran were in the range of 0.30-2.32 microg/ml and 1.45-1.47 microg/ml, respectively. Benfuracarb was not detected in urine, but carbofuran was detected in the range of 0.53-2.66 microg/ml.