An electrical conductivity detector for paper, thin-layer and column chromatography

The Analyst ◽  
1973 ◽  
Vol 98 (1165) ◽  
pp. 251 ◽  
Author(s):  
V. Di Stefano ◽  
P. Marini
Keyword(s):  
Electrical Conductivity ◽  
Thin Layer ◽  
Column Chromatography

The metabolism of carbohydrates by extremely halophilic bacteria: the identification of lactobionic acid as a product of lactose metabolism by Halobacterium saccharovorum

1978 ◽  
Vol 24 (8) ◽  
pp. 898-903 ◽  
Author(s):  
Geraldine A. Tomlinson ◽  
Maureen P. Strohm ◽  
Lawrence I. Hochstein
Keyword(s):  
Thin Layer ◽  
Acid Hydrolysis ◽  
Column Chromatography ◽  
Gluconic Acid ◽  
Halophilic Bacteria ◽  
Galactose Oxidase ◽  
Lactobionic Acid ◽  
Lactose Metabolism ◽  
Furanose Form

Nongrowing cells of Halobacterium saccharovorum oxidized lactose to a product identified as lactobionic acid by thin-layer, paper, and column chromatography, and by identification of the galactose and gluconic acid produced from it after acid hydrolysis. Growing cells oxidized lactose to a product that was identical with lactobionate except that it did not serve as a substrate for galactose oxidase. While the identity of this compound has not been established, it is suggested that the product is lactobionic acid in which the galactose moeity is in the furanose form. Neither lactobionate nor the product produced by growing cells was further metabolized, suggesting that lactose oxidation is not coupled to growth.

Cellulose Thin Layer and Column Chromatography for Resolution of DL-Tryptophan

1980 ◽  
Vol 18 (7) ◽  
pp. 311-314 ◽  
Author(s):  
S. Yuasa ◽  
A. Shimada ◽  
K. Kameyama ◽  
M. Yasui ◽  
K. Adzuma
Keyword(s):  
Thin Layer ◽  
Column Chromatography

scholarly journals Enhancement of Oxidation Resistance of Copper by an Organic Thin Layer and its Influence on Electrical Conductivity

2016 ◽  
Vol 73 (2) ◽  
pp. 198-206 ◽  
Author(s):  
Takuya IKEDA ◽  
Tomoki TAKATA ◽  
Juri TAKAGI ◽  
Kaoru ADACHI ◽  
Yasuhisa TSUKAHARA
Keyword(s):  
Electrical Conductivity ◽  
Thin Layer ◽  
Oxidation Resistance

Assay of Apocarotenal and Canthaxanthin in Foods

1966 ◽  
Vol 49 (5) ◽  
pp. 1078-1083
Author(s):  
M Osadca ◽  
E DeRitter ◽  
R H Bunnell
Keyword(s):  
Solvent Extraction ◽  
Thin Layer ◽  
Column Chromatography ◽  
Absorption Maximum ◽  
Iodine Solution ◽  
Selective Solvent ◽  
Naturally Occurring ◽  
Selective Solvent Extraction ◽  
Coloring Agents

Abstract Methods are presented for determining the carotenoids β-apo-8′-carotenaI and canthaxanthin in foods to which they have been added as colorants. They are extracted by blending or by shaking with appropriate solvents, depending on the nature of the sample, and are separated from naturally occurring pigments and other added coloring agents by selective solvent extraction and/or column chromatography. Concentration is measured by spectrophotometric reading at the absorption maximum after the system is brought to isomerization equilibrium by treatment with iodine solution. Thin layer chromatographic procedures are described for confirming the identities and completeness of separation of the carotenoids.

Notizen: Isolation of Batatasin I from Dioscorea dumetorum Rhizomes

1979 ◽  
Vol 34 (3-4) ◽  
pp. 288-289 ◽  
Author(s):  
M. M. El-Olemy ◽  
J. Reisch
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Column Chromatography ◽  
Spectral Evidence ◽  
Layer Chromatography

Abstract Batatasin I was shown to occur in the fresh rhizomes of poisonous yam (Dioscorea dumetorum Pax.,). It was isolated by column chromatography and identified by chromatographic and spectral evidence. Two other unknown phenanthrenes were shown to occur by thin-layer chromatography.

Surface morphology and electrical property evolution of super-thin Pt film on 6H-SiC substrate during annealing

2011 ◽  
Vol 26 (3) ◽  
pp. 256-261
Author(s):  
Jingjing Yang ◽  
Wenxia Yuan ◽  
Xiaopeng Zeng
Keyword(s):  
Electrical Conductivity ◽  
Electrical Property ◽  
Surface Morphology ◽  
Thin Layer ◽  
Annealing Temperature ◽  
Composition Gradient ◽  
Mechanism Analysis ◽  
Pt Films ◽  
Low Solubility ◽  
Crystalline Graphite

We reported the surface morphology and electrical property of super-thin Pt films, ∼2 nm thick, deposited on 6H-SiC (0001) substrates and subsequently annealed from 400 to 1000 °C. The surfaces of the films were found to have a feature of islands growth, and the sizes of the islands increased with increasing annealing temperature. Free carbon, produced by selective reactions between Pt and SiC, diffused toward the top surface across the product layers due to low solubility and composition gradient of carbon throughout the reaction zone. A dramatic change of electrical conductivity of the films was observed. A mechanism analysis reveals that the origin came from the contribution of aggregation of islands on the surface and formation of Pt silicides and a thin layer of crystalline graphite.

Comparison of Different Soil Leaching Techniques with Four Herbicides

Weed Science ◽  
1975 ◽  
Vol 23 (6) ◽  
pp. 508-511 ◽  
Author(s):  
Chu-Huang Wu ◽  
P. W. Santelmann
Keyword(s):  
Thin Layer ◽  
Column Chromatography ◽  
Waiting Times ◽  
Thick Layer ◽  
Working Hours ◽  
Laboratory Methods ◽  
Thin Layer Method ◽  
Rf Values ◽  
Layer Chromatography ◽  
Herbicide Mobility

Herbicide mobility in soils was compared by three laboratory methods. The Rf values calculated from soil thin-layer chromatography correlated closely with those obtained from soil thick-layer chromatography (r = 0.96). Herbicides leached slightly further in slotted column chromatography as compared with the other methods. The working hours required to conduct a study with each method were in the increasing order of thin-layer, thick-layer, and column chromatography. However, the thin-layer method required the longest waiting times, followed by the column and thick-layer chromatography. If radioactive herbicides are not available or obtainable, the thick-layer chromatography is simplest and quickest. The relative mobility of herbicides studied was fluometuron [1,1-dimethyl-3-(α,α,α-trifluoro-m-tolyl)urea] > napropamide [2-(α-naphthoxy)-N,N-diethylpropionamide] > terbutryn [2-(tert-butyl-amino)-4-(ethylamino)-6-(methylthio)-s-triazine] > trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine). Less herbicide mobility was observed in heavier soil than in sandy soil.

Preparation of 14C- and 3H-Labeled Aflatoxins

1971 ◽  
Vol 54 (5) ◽  
pp. 1027-1031
Author(s):  
J L Ayres ◽  
D J Lee ◽  
R O Sinnhuber
Keyword(s):  
Thin Layer ◽  
Aspergillus Flavus ◽  
Column Chromatography ◽  
Aflatoxin B1 ◽  
Sodium Acetate ◽  
Specific Activity ◽  
Tritiated Water ◽  
New Method ◽  
Extraction And Purification ◽  
Constant Specific Activity

Abstract A new method for the preparation of 14C- and 3H-labeled aflatoxins was devised, using rice as a supporting mold media. Labeled precursors were added to sterile rice and the mixture was inoculated with Aspergillus flavus spores. After a 7 day incubation at 25°C, the toxins were extracted with chloroform and purified by column chromatography and subsequent recrystallization. Aflatoxins B1 and G1 were recovered with 70% efficiency from the culture. Incorporation of radioactivity was examined with glucose-U-14C, sodium acetate-1-14C, and sodium acetate-2-14C. The latter gave the most efficient incorporation of 14C at 0.1% for aflatoxin B1 and 0.05% for aflatoxin G1. Conversion of 3H from tritiated water was 0.006% for aflatoxin B1 and 0.003% for aflatoxin G1. Extensive tests of radiopurity were performed on the labeled toxin which included: recrystallization to constant specific activity, thin layer and column chromatography, and hydrogenation of aflatoxin B1 to tetrahydrodeoxoaflatoxin B1. The rice-culturing technique gave good toxin yields of 1 mg aflatoxin B1/g rice. The purification was simplified by the absence of highly radioactive impurities and no appreciable degradation of labeled toxins was noted throughout extraction and purification.

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