Ahmed M. Kadoum

Distribution and retention of atrazine and carbofuran in farm pond ecosystems

The distribution and retention of atrazine and carbofuran in farm ponds were examined after application of 0.3 ppm of atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-S-triazine] for two years and 0.025 ppm of carbofuran (2,3-dihydro-2,2-dimethyl-7-benzofuranyl methylcarbamate) the first year and 0.050 ppm for the second year. Samples of water, mud, and various biological components for the systems were collected periodically for residue analyses by gas chromatography. Soon after atrazine was applied, it was found in all physical and biological components. No biological magnification was observed. Carbofuran showed up only in the water and mud immediately after application; from then on it was absent from all components. No adverse effects from either pesticide were observed in the biological components.

A rapid micromethod of sample cleanup for gas chromatographic analysis of insecticidal residues in plant, animal, soil, and surface and ground water extracts

SummaryA simple microcolumn chromatographic cleanup method for chlorinated and organophosphorus insecticides has been developed in which a high purity grade 950 of activated silica gel (60–200 mesh) is used. Insecticides are selectively eluted from the adsorbent by different solvent mixtures varying in polarity. Procedures are described for cleanup of residues in plants, grains, animal tissues, soil, and large amounts of ground and surface water.Cleanup is satisfactory for gas chromatographic analysis. All tested insecticides were recovered quantitatively.

Carbamate insecticide removal in laundering from cotton and polyester fabrics

Even though carbamate insecticides are becoming increasingly important for insect control on field crops, few studies have focused on their removal from contaminated textiles. Hence, this study evaluated the effectiveness of selected laundering procedures in removing carbofuran and methomyl insecticides from 100% cotton and 100% polyester medium weight fabrics. After treating the fabric samples with 4.0% (w/w) aqueous solutions of Furadan® 4F Insecticide (carbofuran) or Lannate® L Insecticide (methomyl), they were air dried and laundered, using three detergents [All® (non-ionic), Tide® (anionic), and Wisk® (anionic and non-ionic)] plus water only at two temperatures (warm: 49°C wash/40°C rinse and hot: 60°C wash/49°C rinse). The percentages of insecticide residue remaining on the fabrics after laundering were analyzed by high performance liquid chromatography (HPLC) with a fluorescence detector, and bioassay tests withDrosophilia malanogaster Meigen were used to evaluate their relative toxicity.All of the laundering procedures, including the water only wash, were effective in removing ⩾99% of the carbamate insecticides from both the cotton and polyester fabrics. Among the insecticide/fabric types evaluated, the highest percentages of residue remaining were associated with the polyester fabrics treated with methomyl. After 72 hr, fruit fly mortality occurred on only the methomyl treated polyester laundered in warm water. These findings support those reported in previous studies on the ease with which carbamate contaminants are removed from textiles, compared to other insecticide types.

Cleanup procedure for water, soil, animal and plant extracts for the use of electron-capture detector in the gas chromatographic analysis of organophosphorus insecticide residues

SummaryA simple, aqueous acetonitrile partition cleanup method for analyses of some common organophosphorus insecticide residues is described. The procedure described is for cleanup and quantitative recovery of parathion, methyl parathion, diazinon, malathion and thimet from different extracts. Those insecticides in the purified extracts of ground water, grain, soil, plant and animal tissues can be detected quantitatively by gas chromatography with an electron capture-detector at 0.01 ppm. Cleanup is satisfactory for paper and thin-layer chromatography for further identification of individual insecticides in the extracts.

Activation and standardization of purified silica gel for column chromatographic cleanup of pesticide residue extracts

SummaryActivation and standardization studies have been conducted with high purity grades 950 and 923 silica gel to obtain an effective adsorbent for cleanup of pesticide residue extracts. Activation of silica gel at 130°C or 300°C for a 2-hr period was very satisfactory for separating pesticides from biological materials with high recovery of pesticides. No gain in the activity of the adsorbent resulted from prolonging heat treatment beyond the 2-hr period. It was also found that the activity of the silica gel was not affected by storing it in an air-tight container for as long as 60 days.

Effects of some organophosphorous compounds and their metabolites on sorghum-grain esterase and certain insects attacking sorghum grain

Contribution No. 1014, Department of Entomology, Kansas Agricultural Experiment Station, Manhattan, Kansas, U. S. A. Research supported in part by cooperative agreement No. 12-14-100-9706(51), with Market Quality Research Division, Agricultural Research Service, USDA, Kansas Project 5912. The technical assistance of Charles C. Anderson III is greatly appreciated

A simple starch-gel electrophoretic method to investigate esterase inhibition by common organic insecticides

Starch-gel e lectrophoret ic methods to resolve components os complex prote in mixtures are avai lable to use in analyzing serum from many species, but most analyses are involved and time consuming. Also present starch-gel e lectrophoret ic techniques (6, 7, 8, 9) used to separate blood proteins obtained from Tenebrio mel i tor (L.) larvae give poor separation os components. The obj ec t i ve of this work was to simplify and accelerate the conven-

Degradation of Malathion in Corn, Wheat, and Sorghum Grain of High Moisture Contene

Malathion residues on hard winter wheat, shelled corn, and sorghum grain (15% moisture content) were found to degrade from 93.3, 90.6, and 74.3% 24 h after treatment to 61, 37, and 31%, respectively, after 28 days storage.

A simple agar gel electrophoretic method to investigate esterase inhibition in certain stored grain insects by malathion and its oxygen analogue.

A simple starch-gel electrophoretic method has been reported by Kadoum (3) for separating insect blood proteins during investigations of interactions occurring between common organic insecticides and enzymes. The method describes a simple zone electrophoresis procedure, using agarose as a convenient support medium. This method provides good resolution of esterases in the lesser rice weevil Sitophilus oryzae (L.~ red flour beetle, Tribolium castaneum (Herbst); ~nd lesser grain borer, Rhyzopertha dominica (--~ab~) as well as a means of demonstrating the effects o~alathion and malaoxon on their esterases. Malathion, the principal insecticide used as grain protectant because of its low mammalian toxicity and its effectiveness against storage pests, was chosen.