Chromatographic adsorption analysis
01 Mar 1942-Industrial & Engineering Chemistry Analytical Edition (American Chemical Society)-Vol. 14, Iss: 3, pp 245-249
About: This article is published in Industrial & Engineering Chemistry Analytical Edition.The article was published on 1942-03-01 and is currently open access. It has received 84 citations till now. The article focuses on the topics: Expanded bed adsorption & Adsorption.
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TL;DR: Thin-Layer Chromatography as an Analytical Tool as a Preparative Tool and Qualitative Analysis for Quantitative Analysis.
Abstract: Technique
Thin-Layer Chromatography as an Analytical Tool
Qualitative Analysis
Quantitative Analysis
Thin-Layer Chromatography as a Preparative Tool
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368 citations
01 Jan 1955
TL;DR: Chlorophylls are the green pigments in plants some of which participate in photosynthesis as discussed by the authors, and they can be recognized qualitatively and oftentimes be determined quantitatively.
Abstract: Chlorophylls are the green pigments in plants some of which, and perhaps all, participate in photosynthesis. An understanding of their nature, genesis, transformation, and function in plants requires that they and their near chemical relatives be recognized qualitatively and oftentimes be determined quantitatively. In addition to the use of analytical procedures for the identification and determination of the chlorophylls as participants in plant physiological processes, these methods may be used in various other fields of science and technology some of which are genetics, plant nutrition, certain aspects of pure chemistry, crop production of land and sea, medicine, pharmaceuticals, food technology, and paleontology.
282 citations
TL;DR: In this paper, the quantitative determination of carotenoids in photosynthetic tissues is discussed, which can be done by dissolving the extract in aqueous methanol in a separatory funnel and adding an equal amount of petroleum ether.
Abstract: Publisher Summary This chapter discusses the quantitative determination of carotenoids in photosynthetic tissues. A useful separation of carotenoid pigments into nonpolar carotenes and carotenoid esters in one group, and polar xanthophylls (containing hydroxyl groups) in the other may be accomplished by partitioning the pigments between petroleum ether and aqueous methanol. This can be done by dissolving the extract in aqueous methanol in a separatory funnel and adding an equal amount of petroleum ether. In cases where the carotenoid components are stable toward alkali, it is advantageous to include saponification in the isolation procedure for removing chlorophyll and other saponifiable matter. The pigment is taken to dryness (oil pump); all acetone must be removed from the extract to avoid base-catalyzed formation of condensation products of acetone. The residue is dissolved in a small volume of ether, and the same volume of 10% methanolic KOH solution is added. The approximate content of total carotenoids in an extract may be determined by measuring the optical density of a sample suitably diluted.
191 citations
TL;DR: In this article, the scintillation counting behavior of a group of fifty-five pure crystalline organic compounds has been extensively studied with the goal of developing a better understanding of the Scintillation process and of scintillator behavior.
Abstract: The scintillation counting behavior of a group of fifty‐five pure crystalline organic compounds has been extensively studied. The data obtained have been analyzed with the goal of developing a better understanding of the scintillation process and of scintillator behavior.The materials were carefully purified, and massive crystals were grown. Relative scintillation average‐pulse‐height efficiencies at 30°C and —70°C for cobalt‐60 gamma‐ray excitation, gamma‐ray excited scintillation decay times, and 2537 A ultraviolet‐excited reflection and transmission photofluorescence spectra have been determined. A few solutions were also studied for comparison purposes. The purification and properties of the different materials are discussed in detail.The experimental data have been analyzed on the basis of Birks' photon cascade theory of the scintillation process. The ratio of the scintillation efficiency to the integrated photofluorescence intensity is shown to be a measure of Birks' primary photon production effici...
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248 citations
TL;DR: The α-tocopherol as mentioned in this paper is a possibly the allophante of β-amyrin, which was derived from wheat germ oil thress aflophanates.
170 citations
TL;DR: A provisional formula for α-tocopherol is proposed, which when given in a single dose of 3 mg.
Abstract: We have prepared from the non-saponifiable matter of wheat germ oil thress aflophanates:
1. M.p. 250°. This is a possibly the allophante of β-amyrin. The alcohol regenrated from the allopohante has no vitamin E potency.
2. M.p. 138°, readily crystallizing in long needles. The analysis agree with values required by monollophantes of an alcohol, C39H50O2. The alcohol from this allophante apparenelly has some vitamin E potency, but less than that from the third allophanate.
3. M.p. 158-160°. From this allophanate, the alcohol—for which we propose the name α-tocopherol—when given in a single dose of 3 mg. always enables vitamin E-deficient rats to bear young. α-Tocopherol shows a characteristic absoption band at 2980 A., E1 per cent1 cm. = 90 ca. Treatment with methyl alcoholic silver nitrate converts it to a substance which has absorption bands at 2710 and 2620 A respectively, E1 per centcm. = 480 ca., and possesses and some vitamin E activity.
α-Tocopherol yields a crystaline p-nitrophenylurethane melting at 120-131°. Analyses of both the urethane and the allophanate indicate a provisional formula for α-tocopherol of C29H50O2
155 citations
01 Jan 1938
113 citations
95 citations