Fungicide residues. Part IV. Determination of residues of carboxin in grain by gas chromatography

Farrow, J. E.; Hoodless, R. A.; Hopkinson, Andrew

doi:10.1039/an9750000249

Cited by 5 publications

(2 citation statements)

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“…Chin et al (1970) studied the metabolism of carboxin by barley and wheat plants and developed a method for its direct determination by using gas chromatography with a microcoulometric sulfur detector. Farrow et al (1975) reported on the nitrogen-selective detector gas chromatographic determination of carboxin, after it had been extracted from the grain sample with acetone in a Soxhlet apparatus and concentrated. In this last procedure the limit of detection was at best 0.025 ppm, but the recovery was only checked to 0.5 ppm.…”

Section: Determination Of Residues Of Vitavax and Plantvax In Grainsmentioning

confidence: 99%

“…The grain extracts were not purified and this resulted in an increase in the standing current, a loss of resolution and a shorter column life. Therefore, Farrow et al (1975) recommended that 20-g samples of the grain be employed for the analysis and that the first 10 cm of column packing be replaced after 50 sample injections. When this method was applied to oxycarboxin, it failed, because the response varied by ±25%.…”

Section: Determination Of Residues Of Vitavax and Plantvax In Grainsmentioning

confidence: 99%

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Determination of residues of Vitavax and Plantvax in grains

Tafuri¹,

Patumi²,

Businelli³

et al. 1978

J. Agric. Food Chem.

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A gas-liquid chromatographic method using a nitrogen-selective detector is described for the determination of Vitavax and Plantvax residues in grains. Vitavax and Plantvax are extracted from the grains and the extract is cleaned up. Gas-liquid chromatography is applied to Plantvax following the formation of the reduced derivative. The structure of the reduced Plantvax is established by NMR and infrared spectra. The recoveries of Vitavax from fortified grains varied from 87.2 to 92.1% in the range 0.014.20 mg/kg. The sensitivity was such that Vitavax could be detected down to a level of 0.005 mg/kg. Results for Plantvax recoveries showed that the method can be used in grain extracts for levels down to 0.5 ppm for quantitative determination of Plantvax. Below this limit the reduced Plantvax peak rapidly disappeared as concentration diminished.Carboxin (2,3-dihydro-6-methyl-5-phenylcarbamoyl-1,4-oxathiin, I) and oxycarboxin (2,3-dihydr0-6-methyl-5-phenylcarbamoyl-1 ,4-oxathiin 4,4-dioxide, 11), introduced under the trade names Vitavax and Plantvax, are systemic fungicides: the first is mainly employed for the treatment of cereal seeds against smuts and bunts and the second for the treatment of cereals against rusts (Schlor, 1970). A small part of carboxin is oxidized to oxycarboxin in the plants (Chin et al., 1970).Their use in agriculture has made it necessary to devise a sensitive and specific analytical procedure for determining residues in vegetable foods.Lane (1970) developed a method for measuring the residue of carboxin in plant material by hydrolysis and the colorimetric determination of the aniline so formed by coupling with p-dimethylaminobenzaldehyde. Sisken and Newel1 (1971) increased the quantitative sensitivity required by a residue procedure from 1 to 0.2 ppm by gas chromatographic determination of aniline with a microcoulometric nitrogen detector.These methods, which are subject to interference from various aniline-containing compounds, lacked specificity. Chin et al. (1970) studied the metabolism of carboxin by barley and wheat plants and developed a method for its direct determination by using gas chromatography with a microcoulometric sulfur detector. Farrow et al. (1975) reported on the nitrogen-selective detector gas chromatographic determination of carboxin, after it had been extracted from the grain sample with acetone in a Soxhlet apparatus and concentrated.In this last procedure the limit of detection was at best 0.025 ppm, but the recovery was only checked to 0.5 ppm. The grain extracts were not purified and this resulted in an increase in the standing current, a loss of resolution and a shorter column life. Therefore, Farrow et al. (1975) recommended that 20-g samples of the grain be employed for the analysis and that the first 10 cm of column packing be replaced after 50 sample injections. When this method was applied to oxycarboxin, it failed, because the response varied by *25%. In our preliminary trials no peak for oxycarboxin was found when flame or nitrogen selective detectors...

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Section: Determination Of Residues Of Vitavax and Plantvax In Grainsmentioning

confidence: 99%

Section: Determination Of Residues Of Vitavax and Plantvax In Grainsmentioning

confidence: 99%

Determination of residues of Vitavax and Plantvax in grains

Tafuri¹,

Patumi²,

Businelli³

et al. 1978

J. Agric. Food Chem.

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Dissipation rates of insecticides in six minor vegetable crops grown on organic soils in Ontario, Canada

et al. 1980

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Dissipation rates of diazinon, endosulfan, leptophos, methamidophos, methomyl, parathion and pirimicarb were studied on five minor vegetable crops, including cos and head lettuce, endive, cauliflower and Chinese cabbage. Residues from foliar treatment generally followed an exponential rate of decline. The number of days for residues to drop to below acceptable tolerances was highly dependent on the magnitude of the initial residue; large variations in initial residues were observed between years, between insecticides, and between crop types. Residues of five insecticides and two fungicides used in furrow treatments for onions intended for pickling were determined in the onions at harvest and after pickling. Fensulfothion and fonofos levels were below the accepted tolerance of 0.1 mg kg-l at harvest, while chlorfenvinphos, chlorpyrifos and ethion were present above this level; fungicide residues were not detected. Following pickling, only ethion residues were still present in the onions at levels greater than 0.1 mg kg-1.

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Determination of Organic Compounds in Plant Materials, Vegetables and Fruit

Toxicants in Terrestrial Ecosystems

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Fungicide residues. Part IV. Determination of residues of carboxin in grain by gas chromatography

Cited by 5 publications

References 0 publications

Determination of residues of Vitavax and Plantvax in grains

Determination of residues of Vitavax and Plantvax in grains

Dissipation rates of insecticides in six minor vegetable crops grown on organic soils in Ontario, Canada

Determination of Organic Compounds in Plant Materials, Vegetables and Fruit

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