Effect of pH on the Hydrolysis of Chlorothalonil Aqueous solutions of chlorothalonil (2,4,5,6-tetrachloroisophthalonitrile) were prepared at 0.5 ppm, buffered at pH 5 to 9, and stored in the dark. No hydrolysis was observed at pH 7 or lower. At pH 9, chlorothalonil hydrolyzed to 4-hydroxy-2,5,6-trichloroisophthalonitrile and 3-cyano-2,4,5,6-tetrachlorobenzamide. The rate of decline of chlorothalonil followed first-order kinetics and was determined to be 1.8% per day using gas chromatographic and radiotracer techniques.
GC DETERMINATION OF THIOFANOX RESIDUES tion curves indicate the presence of carboxylate ions that could be explained by the presence of Na salts of some organic acids as impurities.Elementary analyses of the model substance gave the simplest empirical formula of CigH260nN, whereas the empirical formula of the isolate from barley roasted at 250°f or 40 min was found to be CigHgvOnN. Elementary analysis of both the model substance and the isolate from roasted barley indicated that they are of similar composition.The manner by which nitrogen is chemically bound in the brown substance, produced by the process of nonenzymatic browning after the temperature treatment, is not understood. The concentration of the brown substance in roasted barley was unexpectedly high. However, it can be explained by the fact that nonenzymatic browning occurs in two ways. The first occurs from the reaction between amino acid and reducing sugar, and the second occurs from caramelization, which can, but need not, include nitrogen.Isolation of the brown pigments from roasted barley by means of ion-exchange resin Permutit ES confirms that the substance is of an ionic nature and has a negative charge. According to the results obtained from uv and ir spectra (Figures 1 and 2) and from elementary analysis it was concluded that the isolate of the brown substance from roasted barley was of similar composition to the model substance. ACKNOWLEDGMENTThe able technological assays of M. Glogovcan are grate-fully acknowledged.
Five 2,5-dimethyl-1-pyrrolidinecarboxanilides were effective inhibitors of the Hill reaction. However, only thecisisomers were active; thetransisomers were totally inactive. Experiments were conducted using14C-5328 (cis-2,5-dimethyl-1-pyrrolidinecarboxanilide). A correlation existed between resistance of various plants to 5328 and their ability to metabolize it to water soluble metabolites. Velvetleaf (Abutilon theophrastiMedic.) and proso millet (Panicum miliaceumL.) seedlings were very susceptible to 5328 and were unable to metabolize it. Tall morningglory [Ipomoea purpurea(L.) Roth] seedlings were highly tolerant to 5328 and converted it completely to its metabolites. Corn (Zea maysL. ‘DeKalb variety XL-45′) seedlings which were slightly susceptible to 5328 injury were able to metabolize up to 90% of the parent compound. Corn foliage uptake of14C-5328 applied to the soil surface occurred through the adventitious roots.
of allethrin were added to the milk samples taken prior to the start of the spray program in amounts ranging from 0.1 to 0.5 p.p.m. Samples of 200 grams were then analyzed as described under the heading of procedure. The zero point of the scale was set with the fresh reagent (Table I).Known amounts of allethrin in a volatile solvent were added to 100-gram samples of meat. The solvent was INSECTICIDE RESIDUES allowed to vaporize and the meat extracted and tested as described under procedure (Table II).A. Activated carbon packed U-tube B. 500-ml. three-necked, round-bottomed flask, standard taper joints C. Hot water condenser D.
Acid-delinted cottonseeds were treated with 0.5% (w/w) [35S]-or [iV-Me-14C]thiofanox (P), 3,3-dimethyl-1 -(methylthio)-2-butanone 0 -[(methylamino)carbonyl]oxime, before planting. This insecticide was readily taken up by the young seedlings and translocated to the cotyledons and developing leaves where it was rapidly metabolized to its sulfoxide (Pi), 3,3-dimethyl-1 -(methylsulfinyl)-2-butanone 0-[(methylamino)carbonyl]oxime.The level of Pi declined in the cotton leaves with time resulting in the formation of the sulfone (P2), 3,3-dimethyl-l-(methylsulfonyl)-2-butanone 0-[(methylamino)carbonyl]oxime, and water-soluble metabolites. Cottonseeds from laboratory and field plants grown from thiofanox-treated seeds contained less than 5 ppb of carbamate residues.Thiofanox (P), 3,3 -dimethyl-1 -(methylthio) -2 -butanone 0-[(methylamino)carbonyl]oxime, is a potent contact and systemic insecticide being developed by Diamond Shamrock Corporation. When applied to cottonseeds or in the seed furrow at planting, P is readily absorbed and translocated to the plant foliage where it controls many foliar' feeding pests including a number of species from the following orders: Coleóptera, Homoptera, Dyptera, Thysanoptera, and Acariña. In cotton, thiofanox has demonstrated control for up to 8 weeks on thrips, Frankliniella spp.; cotton aphid, Aphis gossypii Glover; cotton fleahopper, Pseudatomescelis beriatus (Reuter); and spider mites, Tetranychus spp., when applied in the seed furrow at the time cotton is planted (Davis and Cowan, 1974) and when applied as a 0.5% by weight seed treatment (Diamond Shamrock Corporation Technical Bulletin, 1973).Whitten and Bull (1974) studied the metabolism of relabeled P in cotton plants and soil. They report rapid oxidation of P to its sulfoxide (Pi), 3,3-dimethyl-l-(methylsulfinyl)-2-butanone 0-[(methylamino)carbonyl]oxime, and sulfone (P2), 3,3-dimethyl-l-(methylsulfonyl)-2-butanone 0 -[(methylamino)carbonyl] oxime. Further degradation of
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.