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: A relatively simple procedure is described for the calculation of equi-eluotropic binary solvent systems in liquid-solid chromatography of steroids using the retention constant of the steroid hydroxyl group in pure solvent.
Abstract: Based on the previously observed proportionality between the retention constant of some mono-and polyfunctional steroids and the retention constant of the steroid hydroxyl group in pure solvent, a relatively simple procedure is described for the calculation of equi-eluotropic binary solvent systems in liquid-solid chromatography of steroids. This method is compared with the proposals of Snyder and Hara.
3 citations
TL;DR: M.S. Tswett pioneered the elution and frontal versions of chromatography and gradient elution, and laid the foundation for a general scientific approach to the solution of analytical problems using chromatographic techniques.
Abstract: The advances of MS Tswett in the field of chromatography were analyzed Most attention was focused on his contribution to the development of chromatography as a scientific discipline (the principal versions of chromatography, the development of physicochemical concepts of a chromatographic process, the roles of main factors affecting separation, etc) Tswett pioneered the elution and frontal versions of chromatography and gradient elution He demonstrated the importance of the nature of mobile and stationary phases and laid the foundation for a general scientific approach to the solution of analytical problems using chromatographic techniques The Tswett's intellectual heritage is actively used in modern chromatography
2 citations
TL;DR: The ultraviolet absorption of khellin provides a quantitative method for its determination in alcoholic solutions that permits the performance of a series of determinations in the same patient, and has the advantage of utilizing only 2 ml.
Abstract: A sctrophotometric method is described for the quantitative estimation of khellin in blood. Chromatographic adsorption of impurities from alcoholic solutions is employed. The absorption curves of khellin in alcohol have been determined and the molar extinction coefficient in the region of 220–350 mμ has been calculated. The ultraviolet absorption of khellin provides a quantitative method for its determination in alcoholic solutions. The method described permits the performance of a series of determinations in the same patient, and has the advantage of utilizing only 2 ml. of blood and very small amounts of reagents. The procedure requires only fifteen minutes to perform.
2 citations
TL;DR: In this article, a portable cabinet with controlled lighting for use in base exchange procedures is described and detailed directions for conducting the base exchange are given and advantages over the original Conner and Straub procedure are pointed out.
Abstract: A portable cabinet with controlled lighting for use in base‐exchange procedures is described. Equipment needed for isolation of thiamin and riboflavin from mixtures is listed. Detailed directions for conducting the base exchange are given and advantages over the original Conner and Straub procedure are pointed out. Photographs of cabinet and equipment are presented, together with sug. gestions for additional uses of the apparatus in routine laboratory procedures.
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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