Heptachlor, Heptachlor Epoxide, and Gamma-Chlordane Residues in Soil and Rutabaga After Soil and Surface Treatments With Heptachlor

Abstract

The distribution of insecticide residues in soil and rutabagas, after soil and surface treatments with heptachlor, was studied by gas-liquid chromatography. Granular heptachlor at 6.6 kg/ha was incorporated into the top 1.27 to 1.90 cm of soil and heptachlor emulsion was applied three times at 4.48 kg/ha on the soil surface. Only about 3% of the applied insecticide was recovered from surface-treated soil three to four months after application, whereas 15% of the insecticide incorporated into the soil was recovered after five months. Rutabagas grown in surface-treated soil had 0.042 p.p.m. of total residues, whereas those from insecticide-incorporated soil had 0.060 p.p.m.Maximum concentration of residue in peel was in the vertical zone where the insecticide had been applied. Lateral movement of pesticides into rutabaga tissues was limited to about 0.5 cm from the periphery. The waxy layer of the rutabaga, representing 2.7% of the whole rutabaga, contained 70% of the residue. The peel contained about 98% of the residue half of which was removed by boiling in water. Boiled pulp was pesticide free.

Effect of commercial processing techniques on carbon-14 labeled lindane- and DDT residues in rapeseed oil

“…studies have shown that commercial and home processing techniques considerably reduce the levels of pesticides in raw garden vegetables (Elkins et al, 1968;Farrow et al, 1966;Farrow et al, 1968;Hemphill et al, 1967;Lamp et al, 1968a and 1968b; Saha and Stewart, 1967;Seidler et al, 1968). While it is rather easy to remove pesticides residues from vegetables by commercial and home processing techniques, it is rather difficult to remove fat soluble pesticides from milk or butter fat by the commercial processing techniques.…”

Validity of using soil fortification with dieldrin to measure solvent extraction efficiency

“…The abilities of various solvents to extract organochlorine pesticide residues from soils have been expressed usually as percentage recovery of a specific pesticide from a fortified sample of dry soil (Decker et al, 1965;Duffy and Wong, 1967;Saha and McDonald, 1967;Saha and Stewart, 1967;Stewart et al, 1965). Such fortification studies do not give an accurate measure of the abilities of solvents to extract field-applied pesticides (Chiba and Morley, 1968).…”