Recent experiments on fumigation

Page, A. B. P.; Lubatti, O. F.

doi:10.1002/jctb.5000591102

Cited by 9 publications

(3 citation statements)

References 6 publications

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“…In addition to absorption, chemisorption of fumigants may also occur, as shown by Page and Lubatti (12) with hydrogen cyanide and by Lewis (9, 10) with methyl bromide. In any event, investigation of the concentration-time patterns of acrylonitrile resulting from its combination with amounts of carbon tetrachloride greater than 1 to 4 may show whether anomalous acrylonitrile waves would be reduced in frequency.…”

Section: Resultsmentioning

confidence: 98%

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Grain Fumigant Determination. Wheat as a Chromatographic Column toward Methyl Bromide, Ethylene Dibromide, Acrylonitrile, Chloropicrin, and Carbon Tetrachloride in the Vapor Phase

Berck¹,

Solomon²

1962

J. Agric. Food Chem.

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Methyl bromide, ethylene dibromide, acrylonitrile, and chloropicrin were applied in the vapor phase, both singly and in admixture with carbon tetrachloride, to the surface of 7-foot columns containing wheat of 12, 16, and 20y0 moisture content, respectively. Air was used as a carrier gas and the composition of the gas-air mixture that emerged from the bottom of each column was assessed polarographically. Chloropicrin, acrylonitrile, and especially ethylene dibromide were strongly sorbed, particularly at 1 6 and 20% moisture. Even up to 13 days at 25' C., ethylene dibromide emerged only in small amounts and at 4.5' C. was consistently zero. Acrylonitrile showed an interesting delayed action. Carbon tetrachloride, which in itself is a mediocre fumigant, increased the peak output of each of the other fumigants at the various temperature and moisture levels under test. Carbon tetrachloride also extended the time when zero concentration was reached. The results were in agreement with earlier work with methyl bromide, ethylene dibromide, and carbon tetrachloride applied in the liquid phase. It is postulated that carbon tetrachloride vapor may act as an eluting agent, with wheat acting as a chromatographic column. The proportions of acrylonitrile-carbon tetrachloride, chloropicrin-carbon tetrachloride, etc., that emerged from the bottom vary with dosage, time, and the temperature and moisture content of the column, and in any event differ considerably from the proportions initially applied. It follows that biological evaluation of fumigants needs analytical data for correct interpretation of results.

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Section: Resultsmentioning

confidence: 98%

“…Thus, when methyl bromide wras applied to wheat of 12 and 16% moisture content at 25°and 4.5°C. (Figure 4), the peak was located at 3 hours.…”

Section: Resultsmentioning

confidence: 99%

Grain Fumigant Determination. Wheat as a Chromatographic Column toward Methyl Bromide, Ethylene Dibromide, Acrylonitrile, Chloropicrin, and Carbon Tetrachloride in the Vapor Phase

Berck¹,

Solomon²

1962

J. Agric. Food Chem.

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“…Their data indicate that fumigation with methyl bromide at lower temperatures and high dosages may result in lower bromide residues than fumigation at higher temperatures and lower dosages. Other fumigants with demonstrated chemisorption capabilities include ethylene dibromide (Bridges, 1956;Metcalf, 1963), hydrogen cyanide (Page and Lubatti, 1940), sulfur dioxide (Burroughs and Sparks, 1964), ethylene oxide and propylene oxide (Gordon et al, 1959;Wesley et al, 1965), and trichloroethylene (McKinney et al, 1957).…”

Section: Resultsmentioning

confidence: 99%

Sorption of phosphine by cereal products

Berck¹

1968

J. Agric. Food Chem.

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Phosphine gas (PH3) was applied at concentrations of 0.15 to 0.60 mg. per liter to wheat, oats, barley, flax, and milled grain products in closed containers. No free PH3 remained in any of the substrates after accelerated aeration with nitrogen. Irreversible sorption, considered chemisorption by the author, was reproducibly obtained under the experimental conditions employed. The amount of PH3 chemisorbed was mainly affected by the type, moisture content, and physical form of the substrate, as well as by temperature and contact time. With milled wheat products, the uptake of PH3 by wheat gluten powder, middlings, bran, and shorts was greater than that by wheat starch, flour, and wheat germ. For four different concentrations used, the absolute amounts of PH3 sorbed were directly proportional to the amounts applied, as for first-order reactions. Presumptive evidence that PH3 binds with proteins and complexes with mineral components of the substrates is discussed.

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Fumigation of agricultural products. V.—The distribution of nicotine vapour in glasshouses

Blackith¹

1953

J Sci Food Agric

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The extension of the bromothymol-blue method to the determination of nicotine vapour in glasshouses is described. The vapour pressure of technical nicotine is discussed, and the factors that influence the distribution of nicotine vapour in glasshouses are assessed.Glasshouses are so leaky that effective fumigation ends when the nicotine has been ebaporated. 0 2 . per 1000 cu. f t . and the rate of evaporation should be about 4 oz. per hour for each of the usual spirit-lamp evaporators. Fumigation should not be done while the temperature is rising because marked layering of the atmosphere is liable to occur. Stirring, in conjunction with the leaky structure, only enhances loss of fumigant.The optimum dosage is about Strong cross-winds are likewise deleterious. IntroductionThe general methods of following the distribution of fumigants in ships, warehouses and special chambers have been extensively investigated and described.' Much less has been published about glasshouse fumigation, although the distribution of nicotine and methyl bromide in glasshouses has been given a preliminaryThe leakage from glasshouses is so much faster than that from even the most makeshift fumigation chamber that it becomes the dominant feature of the fumigation, and makes the sorption of fumigant, which is an important source of loss in most fumigations, less significant.found that insect control was better a t higher temperatures, that winds caused uneven distribution in the glasshouse, and that high humidities had little apparent effect on the toxicity of the methyl bromide used as a fumigant in one of the only two sets of experiments reported. There was some sealing of the soil when this became wet, and soil penetration was then reduced. When nicotine concentrations were measured in large glasshouses, it was found that the concentrations fell to negligible proportions within an hour of beginning the fumigation.2 Better results were obtained in dry rather than wet conditions.

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Recent experiments on fumigation

Cited by 9 publications

References 6 publications

Grain Fumigant Determination. Wheat as a Chromatographic Column toward Methyl Bromide, Ethylene Dibromide, Acrylonitrile, Chloropicrin, and Carbon Tetrachloride in the Vapor Phase

Grain Fumigant Determination. Wheat as a Chromatographic Column toward Methyl Bromide, Ethylene Dibromide, Acrylonitrile, Chloropicrin, and Carbon Tetrachloride in the Vapor Phase

Sorption of phosphine by cereal products

Fumigation of agricultural products. V.—The distribution of nicotine vapour in glasshouses

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