Dieldrin: Extraction of Accumulations by Root Uptake

Soybeans (Glycine max [L.] Merr., var. ‘Clark’) and cotton (Gossypium hirsutum L., var. ‘Acala 4‐42’) were grown in Lakeland sandy loam and Hagerstown silty clay loam soils treated with 0.5 ppm 14C‐DDT, ‐dieldrin, ‐endrin, and ‐heptachlor. Periodically, the top portion of one plant per pot was harvested and assayed for insecticide. At maturity, the seed and cotton lint were separated from the hay and assayed separately. Two methods of assay were used, i.e., gas‐liquid chromatography and 14C counting by liquid scintillation. Total 14C‐residue concentrations in soybeans for all four insecticides increased linearly during active growth stages, whereas highest 14C‐residues in cotton were found at the first harvest. No parent DDT or heptachlor was detected in any of the soybean or cotton samples by gas‐liquid chromatographic determination, though small amounts of unidentified DDT residues were detected by liquid‐scintillaton counting of plant extracts of both species. Heptachlor epoxide was present in soybeans at less than 0.1 ppm in hay and less than 0.04 ppm in seed. No heptachlor epoxide was detected in cotton, but unidentified 14C‐heptachlor residues were present at an equivalent of less than 0.065 ppm. Dieldrin residues ranged as high as 0.3 ppm in soybean hay and 0.09 ppm in seed. Endrin residues ranged as high as 0.5 ppm in soybean hay and 0.1 ppm in seed, though actual endrin was less than these values. Dieldrin and endrin residues in cotton hay were below 0.03 ppm and none was detected in seed or lint. The use of 14C‐labeled insecticides demonstrated that all 14C‐residues were not removed from plants. Furthermore, discrepencies between gas‐liquid chromatography and 14C determinations of plant extracts indicated endrin degradation products were present. Soil type influenced the plant uptake of these insecticides, especially endrin. Plants grown in the Lakeland s1 soil concentrated greater insecticide amounts than the Hagerstown sicl, presumably because of the lower organic matter content of the Lakeland soil. Cotton removed considerably more insecticides from soils than soybeans because of their greater mass. Based on these results, cropping would not be an efficient method of removing chlorinated insecticides from contaminated soils.

Section: Analyticalmentioning

confidence: 99%

Plant Uptake of Chlorinated Insecticides from Soils

Nash¹,

Beall²,

Woolson

1970

“…Control samples were used for background, which was subtracted out. Table 1 gives the values from the initial comparative HAM extraction with that of the CM extraction (Mumma et al, 1966). Florisil column cleanup of extracts prior to counting consisted of 200 ml 6 + 94 for DDT and heptachlor residues and 200 ml 15 + 85 for dieldrin and endrin residues.…”

Section: Determinationmentioning

confidence: 99%

“…Several reviews and evaluations of these procedures exist (Cooke and Williams, 1965; Burke and Porter, 1966;Sans, 1967;Stoherr et al, 1967;Ware and Dee, 1968;Wheeler and Frear, 1966;and Williams, 1968). Mumma et al (1966) observed that dieldrin-3 6CI (1,2,3,4,10,10-hexachloro-6, 7 -epoxy-1, 4, 4a, 5, 6, 7, 8, 8a-octahydro-l,. 4-e!ldo, exo-5,8-dimethanonaphthalene) was not quantitatively removed from plants, grown in sand treated with _the labeled dieldrin, when extracted by the standard Mills, Onley, and Gaither (1963) procedure.…”

mentioning

confidence: 99%

Extraction and Cleanup of 14C‐Chlorinated Insecticides from Cotton Grown in Treated Soils

Nash¹,

Beall

1970

Dry cotton hay or seed samples from plants grown in 0.5 ppm 14MC‐DDT, ‐dieldrin, ‐endrin, and ‐heptachlor treated soils were subjected to exhaustive Soxhlet extraction with chloroform/methanol (CM), hexane/acetone (HA), hexane/acetone/methanol (HAM), or hexane/acetone/ methanol/water (HAMW). Extracts further were fractionated by selective elution from Florisil columns and the 14C‐insecticide residues determined. The relative extracting power of the solvents was HAMW>HAM=CM>HA; this applied to all insecticides except DDT, whose residue was too low for reliable comparison. No solution removed all the 14C‐residue from plant tissue. HAM afforded greater simplicity and less time in cleanup compared to CM. One dieldrin degradation product, three endrin degradation products, and three heptachlor degradation products, which includes heptachlor epoxide, were believed extracted from cotton hay with HAMW.

“…After removing samples for quantitative ana:.ysis through combustion, the remaining plant shoots from the four replications were bulked and extracted for 12 hours in a Soxhlet apparatus with 100 ml chloroform-methanol (1:1 v/v), similar to the method of Mumma et a!. (15), for finely ground dry hay. As a check on the extraction and cleanup procedure, samples from plants grown in non-treated soil were fortified with the appropriate 14 C-labeled insecticides and subjected to the identical procedure.…”

Section: Residue Analysismentioning

confidence: 99%

Crop Seedling Uptake of DDT, Dieldrin, Endrin, and Heptachlor from Soils¹

Beal¹,

Nash²

1969

In greenhouse experiments, soybean, wheat, corn, alfalfa, bromegrass, and cucumber seedlings took up various amounts of DDT, dieldrin, endrin, and heptachlor residues from five soils treated with 0.5 or 5.0 ppm insecticide. Residue concentrations in plants were usually well below the soil treatment rates, though endrin and heptachlor residues in alfalfa and bromegrass exceeded the treatment rate of some soils. The order of residue uptake in increasing amounts was DDT < dieldrin < endrin < heptachlor. Correlations calculated between residues in seedlings and several soil characteristics revealed that organic matter negatively affected the uptake of DDT, dieldrin, and heptachlor. Silt negatively affected endrin uptake. Soil moisture content at 0.33 bar tension negatively affected DDT and dieldrin uptake by alfalfa. No significant correlations were found between uptake and soil pH, cation exchange capacity, or clay content. Soil analysis, 14 or 20 months after insecticide application, revealed residues of the insecticides, in increasing order of persistence, to be heptachlor < dieldrin ≈ endrin < DDT. Correlations calculated between residues in soils and the soil characteristics above, revealed that persistence was positively correlated with soil organic matter.