摘要:

AbstractThe activity of the (+)‐trans‐chrysanthemic acid ester of (±)‐allethrolone (Bio‐allethrin) is shown to be superior to that of the (±)‐cis, trans‐isomers (allethrin), against houseflies, two species of grain beetle and larvae of the yellow fever mosquito. The efficiency of the (+)‐trans‐isomer compares favourably with that of pyrethrins when each is used alone or with p

ISSN:0031-613X    

DOI:10.1002/ps.2780010601

出版商:John Wiley&Sons, Ltd    

年代:1970

数据来源: WILEY

摘要:

AbstractThe epoxidation of aldrin and factors influencing this reaction were studied with buffered, aqueous, cell‐free preparations obtained from unbroken roots of laboratory‐grown peas. Aldrin was available to the epoxidising enzymes at concentrations which far exceeded its reported water solubility. Under the experimental conditions, the optimum pH for the reaction was 6·5 using 0·02Mphosphate buffer. The reaction rate increased up to 35°c, and decreased with higher temperatures. Various treatments indicated that the epoxidising factor was soluble, and not dependent on the presence of intact cells or cell organelles. No need could be shown for the cofactors NADPH2and Mg2+, which are required for animal microsomal oxidations. Inhibitor studies indicated both differences and similarities between the system studied here and animal microsomal prepar

ISSN:0031-613X    

DOI:10.1002/ps.2780010602

出版商:John Wiley&Sons, Ltd    

年代:1970

数据来源: WILEY

摘要:

AbstractA field trial is described in which a spray race was used to compare the depletion rates of two chlorfenvinphos cattle dip emulsifiable concentrates under practical conditions.The trial was designed to guard against any biases in the comparison of the concentrates, and the statistical analysis of the results showed that there was a significant difference between the depletion rates of the two formulations.

ISSN:0031-613X    

DOI:10.1002/ps.2780010603

出版商:John Wiley&Sons, Ltd    

年代:1970

数据来源: WILEY

摘要:

AbstractUnder field conditions, there was little loss of herbicidal activity following spring application of pronamide when the soil temperature remained below about 13°c, but under normal summer conditions loss was rapid (half‐life 2–4 weeks). The rate of loss was retarded when the surface soil became very dry. After autumn application, there was no change in activity during the winter months and assays on samples taken in the following spring showed that little leaching had taken place from the surface 5 cm. In laboratory studies, breakdown was shown to follow first‐order kinetics. Half‐lives at 10% soil moisture were 29 days at 23°c, 63 days at 15°c and 140 days at 8°c. At 23°c the half‐life was extended to 52 days when the soil moisture content was r

ISSN:0031-613X    

DOI:10.1002/ps.2780010604

出版商:John Wiley&Sons, Ltd    

年代:1970

数据来源: WILEY

摘要:

AbstractThe growth‐regulating activity of a number of 2‐susbstituted thiazole‐and thiazoline‐acetic acids is reported. 2‐ChIorothiazole‐4‐acetic acid showed appreciable activity in the wheat and pea tests, whilst activity was also observed with the 2‐amino‐, 2‐methylamino‐and 2‐methyl‐analogues. 2‐Substituted thiazoline‐acetic acids were inactive. The activity of these compounds,N‐(carboxymethyl)‐rhodanine and other acids is discussed in relation to the usual structural

ISSN:0031-613X    

DOI:10.1002/ps.2780010605

出版商:John Wiley&Sons, Ltd    

年代:1970

数据来源: WILEY

摘要:

AbstractA number of methods in common use for determining amounts of bromine‐containing compounds occurring as residues in foodstuffs, primarily as a result of commodity or soil fumigation, do not distinguish between bromide ion and organically bound bromine. Although such compounds may differ widely in their toxicity, national and international schedules have included tolerances for total bromide determined as ‘inorganic bromide’.A method is described in which ionised bromide in foodstuffs is quantitatively converted to 2‐brompethanol (ethylene bromohydrin) by reaction with ethylene oxide in an acid medium. The 2‐bromoethanol produced is determined in processed extracts by gas‐liquid chromatography. Residual methyl bromide and ethylene dibromide (1,2‐dibromoethane), neither of which react with ethylene oxide under the conditions prescribed, are separated and determined concurrently.With foodstuffs which did not contain organo‐bromine compounds, good agreement was observed between results obtained by the gas chromatographic method and by total bromide determination involving alkali digestion, controlled ashing, extraction of ash and wet oxidation.In the light of the more specific methods of determination now available, some clarification in tolerance schedules for residual bromine compounds in foodstuf

ISSN:0031-613X    

DOI:10.1002/ps.2780010606

出版商:John Wiley&Sons, Ltd    

年代:1970

数据来源: WILEY

摘要:

AbstractProcedures are described for the analysis of crops for residues of tetrachlorvinphos (Gardona,trans‐isomer of dimethyl 1‐(2′,4′,5′‐trichlorophenyl)‐2‐chloroyinyl phosphate) insecticide together with methods for the analysis for residues of its isomer and its conjugated and non‐conjugated breakdown products. Suitable procedures for the extraction are described together with procedures for the cleanup of the extracts by partition or column chromatography and final analysis down to 0·01 ppm or less by gas‐liquid chromatography with electr

ISSN:0031-613X    

DOI:10.1002/ps.2780010607

出版商:John Wiley&Sons, Ltd    

年代:1970

数据来源: WILEY

摘要:

AbstractApples treated with tetrachlorvinphos (Gardona, trans‐isomer of dimethyl 1‐(2′,4′,5′‐trichloropheny1)‐2‐chlorovinyl phosphate) insecticide under field conditions in several countries in 1965, 1966 and 1967 have been analysed at intervals after treatment for residues of tetrachlorvinphos itself, its cis‐isomer and seven potential breakdown products. Residues of up to 10 ppm of tetrachlorvinphos were detected immediately after the last of three applications of tetrachlorvinphos (diluted to 0.16% active material). The initial half‐life of the tetrachlorvinphos was on average about 0.5 weeks under U.K. conditions and only 10% of the tetrachlorvinphos remained unchanged at 2 weeks after application. The overall chemical persistence of the wettable powder formulation was not significantly different from that of the emulsifiable concentrate formulation.Within 8 weeks of the application the residues were mainly of tetrachlorvinphos itself, its cis‐isomer and the alcohol 1‐(2′,4′‐5′‐trichlorophenyl)ethan‐l‐ol, in free and sugar‐conjugated forms. The residues of the conjugates of this alcohol (up to 0.92 ppm) were generally present in higher concentration at 6‐8 weeks after the application than were the residues of the other components. Whilst residues of other breakdown products were detected on the apples their individual residues were below 0.05 ppm and generally below 0.01 ppm at 6 weeks or more after the last of

ISSN:0031-613X    

DOI:10.1002/ps.2780010608

出版商:John Wiley&Sons, Ltd    

年代:1970

数据来源: WILEY

摘要:

AbstractA wide range of crops including top fruit, cereals, brassicas, root vegetables and cotton from field trials in several countries in 1965, 1966, 1967 and 1968 have been analysed for residues of tetrachlorvinphos (Gardona,trans‐homerof dimethyl 1‐(2′,4′,5′‐trichlorophenyl)‐2‐chlorovinyl phosphate) foliar insecticide, its isomer and its potential breakdown products.The residues under field conditions were mainly of tetrachlorvinphos, its isomer and 1‐(2′,4′,5′‐trichlorophenyl)ethan‐1‐ol in free and sugar‐conjugated forms. Tetrachlorvinphos was not unduly persistent on the crops and its initial half‐life varied from 2 days on cabbage, to 7 days on potato foliage and to 12 days on pears (after the last of five applications). From one week after the final application onwards the highest residues of tetrachlorvinphos observed were on olives (1 ppm after 18 days after a single application of 0·1 % active material), maize leaf (2·8 ppm at 9·5 weeks after the last of two applications at 3 kg/ha), and cabbage (1·9 ppm at 12 days after the last of three applications at 0·5 kg/ha). The maximum residues of the alcohol in the free form were 3·2 ppm on maize leaf at 8 weeks from the second application at 1·5 kg/ha and in the conjugated form were 1·0 ppm on cauliflowers at 6 days after t

ISSN:0031-613X    

DOI:10.1002/ps.2780010609

出版商:John Wiley&Sons, Ltd    

年代:1970

数据来源: WILEY

ISSN:0031-613X    

DOI:10.1002/ps.2780010610

出版商:John Wiley&Sons, Ltd    

年代:1970

数据来源: WILEY