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A new approach is proposed for liquid/solid extraction of retinol and alpha-tocopherol from samples, using a disposable kieselguhr cartridge. The substitution of the mixture methanol-ethanol-n-butanol (4 + 3 + 1) for methanol in the alkaline hydrolysis solution makes it now possible to process fatty samples. Methanol is necessary to solubilize the antioxidant ascorbic acid, and a linear chain alcohol such as n-butanol is necessary to reduce the size of soap micelles so that they can penetrate into the kieselguhr pores. In comparisons of the proposed method with conventional methods on mineral premixes and fatty feedstuffs, recovery and accuracy are at least as good by the proposed method. Advantages are increased rate of determinations and the ability to hydrolyze and extract retinol and alpha-tocopherol together from the same sample. 相似文献
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Changes of chemical forms of metallic zinc and zinc sulfide during the composting process of municipal solid waste in oxygen conditions have been determined. Speciation of zinc was carried out by means of sequential extraction. It has been found that contamination of the waste with Zn is dangerous to the environment because zinc accumulates in bioavailable forms - organically bound and carbonate. Zinc sulfide remains mainly in a less mobile sulfide form. The composting process increases the mobility of zinc insignificantly. 相似文献
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Turek Marian Korolewicz Teofil Ciba Jerzy Cebula Jan 《Water, air, and soil pollution》2002,135(1-4):311-323
Total content of zinc and other metals has been assayed in thesludge that remained after leaching zinc-bearing smelting losswith sulfuric acid. The paper also presents zinc speciationcarried out by means of the sequential extraction by Rudd and an analysis of chemical forms of zinc. It has been found thatzinc occurs mainly in the mobile, bioavailable, soluble form and in the moderately mobile, carbonate form. The speciationcarried out showed that zinc occurred in the sludge in the following forms (mg kg-1): sulfate 143 000, oxide 79 000,metallic 68 200, siliceous 35 500, sulfide 20 800 and ferrate18 500. Preparatory extraction of zinc from the sludge usingwater, sodium salt of ethylenediaminetetraacetic acid (EDTA)and acetic acid has also been conducted. 相似文献
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Zołotajkin M Ciba J Kluczka J Skwira M Smoliński A 《Water, air, and soil pollution》2011,216(1-4):571-580
The research was carried out in the spruce forests of Barania Góra (Silesian Beskids, Poland) affected by pandemic dying of trees. Twenty-seven samples were collected from the O layer in two plots: 17 in a cut down forest infested with insect pests (bark beetle) and ten in a 120-year-old healthy forest. The analyses covered basic parameters (pH(H2O), pH(KCl), w(org), C(tot), N(tot), CEC) and the concentrations of aluminium in the fractions leached with 0.1?M BaCl(2) (Al(exch)), 0.5?M CuCl(2) and 0.1?M Na(4)P(2)O(7) (Al(bio)) solutions. The total aluminium concentration in the soil was assayed digesting samples with hydrofluoric acid. The effect of pH and organic matter content on the amount of exchangeable (Al(exch)) and bioavailable (Al(exch)) aluminium in the soil was analysed. It has been found that the soils in both plots are strongly acidic and contain 550 to 1,700?mg?kg(-1) of exchangeable aluminium and 1,200 to 4,800?mg?kg(-1) of bioavailable aluminium. The lack of disease symptoms in the spruce trees in plot 2 can be explained by the higher content of organic matter in the soil. Unfortunately, one might expect that the high concentration of exchangeable aluminium will also cause the trees in the area to wither. 相似文献
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Ciba P Schicktanz S Anders E Siegl E Stielow A Klink E Kruse C 《Fish physiology and biochemistry》2008,34(4):367-372
In vitro cultures of native fish cell lines are of great importance, both for basic research and applied science. In particular,
there is strong demand for long-term growable cell lines from breeding fish, like sturgeon. Here, we describe the culture
of cells from Siberian sturgeon (Acipenser baerii) head kidney. The cells have so far been cultured over a period of 12 months (24 passages). Cytochemical and immunocytochemical
examination suggests that, in vitro, the cells exhibit markers that are indicative for different cell types. In particular,
fat storing cells (adipocytes) were observed, and the expression of cytokeratins and glial fibrilar acidic protein (GFAP)
can be concluded on the basis of immuncytochemical analysis. The observation of different morphologies additionally underlines
the heterogeneity of the cell population and matches the typical behaviour of in vitro cultures of stem/progenitor cells.
Different applications can be imagined. 相似文献
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The organic fraction of municipal wastes has been composted on the laboratory scale. In the obtained compost the content of cadmium, cobalt, copper, manganese, nickel, lead and zinc were determined, as well as the speciation i.e, the form of their occurrence, making use of Rudd's method of sequential extraction. The investigations also concerned the way of removing these metals from the compost by means of leaching with solutions of sulphuric and nitric acid, as well as by electrochemically separating the metals from the solution after the compost had been leached with sulphuric acid. It has been found that the application of the electrochemical method with varying pH values of the leaching solution within the range of 6.8–2.8 allows for the separation of 83.5% Cd, 55.0% Co, 65.4% Cu, 59.4% Mn, 70.3% Ni, 90.5% Pb and 56.2% Zn. 相似文献
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Abstract. Total concentrations of heavy metals in soils were measured before and after the catastrophic floods of 1997, which devastated most districts within the commune of Racibórz in southern Poland. The assays covered lead, zinc, cadmium, chromium, nickel and copper. Analyses on soil samples taken in 2002, after the floods, were compared with those of 1992, taken as part of regular monitoring. There was an increase in the mean concentrations of heavy metals as a consequence of the flooding. Only a small part of this increase may be due to changes in the method of analysis between the two dates. The mean concentrations of heavy metals after flooding did not exceed the permissible levels for Polish soils. Permission was therefore granted to continue using much of the flooded land for farming. However, the investigations located a number of places where heavy metals were above permissible levels. Some of these were a consequence of the floods, but others were considered to be due to contamination from previous industry. Where high concentrations were found, land was excluded from agricultural use. 相似文献
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