Regression techniques for estimating total DDT and TDE residues in tobacco

Abstract

A procedure is described for estimating total resi-were substituted into the equation, and the caldues of DDT and T D E in tobacco from the anal-

Insecticide Residues on 1972 U.S. Auction-Market Tobacco

“…Over 900/o of the flue-cured samples were positive for toxaphene in 1972. This contrasts with the 1970 sampling where less than 30°/o contained toxaphene (4). The.…”

“…The average over all belts for DOT + TOE was 0.85 ppm. This value is about 14 °/o of the 1970 mean of 6.1 ppm (4).…”

“…Frequency distributions for various concentration ranges are shown in Table 2 for the 1968 and 1970 crops (4,5) as well as the 197.2 crop. These data show that in 1968 about 99 °/o of the samples contained DOT + TOE in excess of 10 ppm, whereas in 1972 none of the samples contained 10 ppm.…”

Further Investigations into the Metabolism of Endosulfan l, Endosulfan ll and Endosulfan Sulfate in Tobacco Leaf

“…Leaves from the tobacco plants were analyzed for endosulfan and its metal?olites at the har- • vesting Stage, and later, when flue-cured. From the residue data obtained we conclude that [1) In green tobacco leaf endosulfan I, found in very small amounts, is the only metabolite of endosulfan sulfate, and that endosuJfan 11 is the main endosulfan sulfate metabolite in flue-cured tobacco leaf; [2] The loss of residues during the curing process depends largely on the residue level of this pesticide in the green tobacco leaf; [3] The loss of pesticide during the curing process is mainly due to volatilization; and [ 4] Smallest amounts of residues are lefl: in tobacco leaf with endosulfan I treatments. (2] que la perte de rCsidus durant le processus de s&hage depend a un haut degr6 du niveau de residus de ce pesticide dans la feuille verte du tabac, [3) que la perte de pesticide durant le processus de sechage est due principalement a la volatilisation et [4] qu'il reste les plus petites quantitCs de r&idus dans la feuille de tabac lorsqu'elle a subi des traitements a l'endosulfan I.…”

Effects of freeze-drying on residues of TDE, DDT, and endosulfan in tobacco

“…This legislation, providing regulations to become effective January 1, 1978, may preclude sale of tobacco to the German manufacturer if residues on the leaf product exceed tolerances. While restrictions to the sale or use of persistent insecticides, including DDT and TDE, are producing dramatic reductions in residue levels of U.S. auction market tobacco (Domanski and Sheets, 1973;Domanski and Sheets, 1975;Gibson et al, 1974), it may be difficult to reduce residues to such low levels.…”