Degradation of organophosphorus and carbamate pesticides in soils--HPLC determination.

Best conditions suited for the extraction and trace analysis of dimethoate, malathion, methyl-parathion, carbaryl, carbendazim and carbofuran in soils, using HPLC, were established. This was followed by studies related to persistence of residues in different soils. Half-life and time taken for 95% dissipation were determined in each case. Higher pH, moderate moisture and high calcium carbonate content aided degradation while organic matter increased persistence.