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Journal ArticleDOI

A proposed non‐ashing technique employing ion‐exchange resins for the determination of lead in wine

01 Jul 1958-Journal of the Science of Food and Agriculture (John Wiley & Sons, Ltd)-Vol. 9, Iss: 7, pp 401-403
TL;DR: In this paper, a Dowex-50 column was used to pass the wine free from solid particles and eluate with 4N-HCl. The lead was determined in the eluate using dithizone.
Abstract: The method proposed is to pass the wine (free from solid particles) down a Dowex-50 column and elute with 4N-HCl. The lead is determined in the eluate with dithizone. Recovery of added lead (2 p.p.m.) is 81–101% and results agree well with those by the iodine pentoxide method,2 although they are rather less consistent. Determinations require only 3 instead of 10 hours. The procedure is recommended for control purposes to establish if a sample contains less than the statutory limit of 1 p.p.m. of lead.
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Journal ArticleDOI
TL;DR: In most species, levels of Cu and Mo were highest in the early samplings and decreased with advancing maturity, while the S content was more uniform in the first cycle but increased considerably in the second cycle, especially in reed canarygrass.
Abstract: Each of the species birdsfoot trefoil (Lotus corniculatus L.), timothy (Phleum pratense L.), bromegrass (Bromus inermis Leyss.), orchardgrass (Dactylis glomerata L.), reed canarygrass (Phalaris arundinacea L.) and creeping red fescue (Festuca rubra L.) was grown in the field on 10 plots sampled at weekly intervals in rotation from June 13. Each plot was resampled after 6 weeks and all samples were analyzed for copper, molybdenum and sulfur. In most species, levels of Cu and Mo were highest in the early samplings and decreased with advancing maturity. Second-cut samples tended to be higher in Cu, Mo and S than first-cut samples. The S content was more uniform in the first cycle but increased considerably in the second cycle, especially in reed canarygrass. The ranges in Cu content were 7.4 to 14.1 ppm for birdsfoot trefoil and 3.7 to 11.4 ppm for the grasses. Mo ranged from 1.9 to 8.1 ppm in birdsfoot trefoil and from 1.0 to 6.5 ppm in the grasses. The overall range in S content was from 0.14 to 0.95%. The...

8 citations

Journal ArticleDOI
TL;DR: In this article, the effects of the application of fertilisers, especially N and trace elements, on the content of Co in mixed grassland herbage and its main constituent species, have been studied.
Abstract: The effects of the application of fertilisers, especially N and trace elements, on the content of Co in mixed grassland herbage and its main constituent species, have been studied. Data have been obtained from field experiments on three mineral soils and on a deep acid peat. The herbage was cut at the silage stage of growth three or four times a year for at least three successive years. Without added Co, N applications increased Co content in herbage on peat but reduced it on mineral soils mainly by eliminating clover which had a higher Co content than grasses. Applying 0.5 kg ha−1 Co as cobalt sulphate increased herbage Co content, the increase being greater on peat than on mineral soils. These increased levels were unaffected by N applications on mineral soils but were further increased by applied N on peat. The number of years during which the Co additions were effective in producing herbage containing at least 0.1 mg Co kg−1 dry matter varied on the different soils, ranging from barely three years on one mineral soil to over five years on peat. Without added Co the last cuts in October usually had the highest Co content and the first cuts in June the lowest. With added Co, the seasonal effects were more variable, but the Co content in the herbage frequently decreased from the first to the last cuts.

7 citations

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28 Feb 2010

17 citations

Journal ArticleDOI
TL;DR: In this paper, a more rapid procedure was described for the destruction of organic matter in wines, grapes, grape must, tinned food and urine, prior to the routine estimation of lead.
Abstract: A more rapid procedure is described for the destruction of organic matter in wines, grapes, grape must, tinned food and urine, prior to the routine estimation of lead. The method involves the initial digestion of the material with iodine pentoxide and concentrated nitric acid, followed by evaporation to dryness, and ashing at 480°. The lead in the residue is then determined colorimetrically after extraction with dithizone in chloroform.

1 citations