摘要:

A high-pressure liquid chromatograph is described which will deliver eluent under pressures up to 60000 lb/in.2This instrument is compared to other common liquid chromatographic methods using Methyl and Ethyl Orange on silica. High pressures had a marked effect upon each distribution ratio and improved the separation.

ISSN:0037-2366    

DOI:10.1080/01496396908052271

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

A simple relationship between the over-all thermodynamic equilibrium constant and the thermodynamic equilibrium constants for the individual partition states that occur within a linear multistate chemical system is derived. The interrelationships between the various parameters that characterize gas-liquid systems—the symmetrical activity coefficient at infinite dilution, Henry's constant, and the partition coefficient—are treated in detail to demonstrate the application of the theoretical results.

ISSN:0037-2366    

DOI:10.1080/01496396908052272

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

The enrichment of very dilute surface-active substances when air or nitrogen bubble through the solution is known as bubble fractionation. The addition of vapors of certain organic liquids has led to an improved and accelerated separation method called booster bubble fractionation (BBF). For the fractionation of dyes in a test apparatus, pentane and chloroform appeared as excellent boosters while ethyl ether and ethyl acetate had no effect. Diagrams showing several foam heights and a periodically changed surface-active Patent Blue content in the bulk demonstrated that water and organic solvents form layers which are only stable in the presence of the surface-active compounds. The gas cycle saturator/fractionator/top-fraction-receiver was operated by a peristaltic pump, the liquid passing by gravity. In a continuous separation process of both 10 ppm and 1 ppm Patent Blue/Neucoccin solutions at 10 liters/hr (=25 × fractionator volume), PB was concentrated by a factor of 10 in the top fraction and nearly totally recovered. Säuregrün, which shows no shift in foam fractionation, could be enriched by a factor of 7 by BBF. The volatility and low solubility of the boosters offer fractions with negligible reagent pollution. Because of a possible specific relationship between boosters and surface-active substances, bubble chromatography with selected organic vapors is suggested.

ISSN:0037-2366    

DOI:10.1080/01496396908052273

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

By using established equations and techniques, it is possible to compute sucrose gradients which are optimized to minimize volume expansion of a zone during sedimentation in zonal rotors. These gradients have been tested experimentally, and it has been found that the greatest expansion of the sample zone occurred during the early stage of sedimentation. Following this expansion, the gradient maintained the volume within the limits set by the calculations.

ISSN:0037-2366    

DOI:10.1080/01496396908052274

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

The two distinct soybean trypsin inhibitors, namely Kunitz and Bowman-Birk inhibitors, were isolated from various commercial sources by isoelectric focusing in the narrow pH 3–6 range in sucrose gradients. The Kunitz inhibitor was also isolated by the same procedure from an aqueous soybean water extract subjected to preparative gel filtration on Sephadex G-25. The Kunitz inhibitor was focused at pH 4.5, and the Bowman-Birk inhibitor at pH 4.3. The two purified proteins were found to be immuno-chemically different. Disc electrofocusing on polyacrylamide gels in the pH 3–10 range was shown to be a simple and high resolution method for detection of heterogeneous preparations of the two inhibitors.

ISSN:0037-2366    

DOI:10.1080/01496396908052275

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

The fundamental equations for calculating the extent of separation are given for four different types of multicontact separation systems: crosscurrent distribution with discrete equilibrium contacts, crosscurrent distribution with differential contact, countercurrent distribution with discrete equilibrium contacts (binomial distribution), and countercurrent distribution with differential contact (Poisson distribution). Optimum values for the number of contacts, tube cutoff point, extent of separation, and distribution coefficients are derived. A method for comparing all separation techniques on an equivalent basis is proposed.

ISSN:0037-2366    

DOI:10.1080/01496396908052276

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

By using a relatively new liquid phase of moderate polarity (OV-225, Supelco Inc., Bellefonte, Pa.), we have significantly improved the gas-liquid chromatographic analyses of certain steroid hormones from human plasma. This liquid phase has afforded us with nearly complete separation of the free steroids from contaminating organic impurities on the GLC column, thus increasing the accuracy of our analyses due to the Gaussian nature of the recorded chromatographic peaks. Hence, the need for preparing chemical derivatives of these steroids prior to GLC has been eliminated.

ISSN:0037-2366    

DOI:10.1080/01496396908052277

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

In two previous papers (1,2), we reported the effect of several operational parameters on separations by gel permeation chromatography (GPC). These studies included the effects of (a) solvent flow rate, (b) sample concentration, (c) sample molecular weight, (d) particle size, and (e) operating temperature. In this present study, we used extremely large particles (200–300 μ diameter) at flow rates up to 10 ml/min. This was done to magnify solute diffusion effects in hope of gaining a better understanding of the permeation process. By using the relatively large particles, interstitial spaces between particles will be wider and the gel pores deeper than with particles normally used (less than 75 μ) in GPC.

ISSN:0037-2366    

DOI:10.1080/01496396908052278

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

This is a scanned image of the original Editorial Board page(s) for this issue.

ISSN:0037-2366    

DOI:10.1080/01496396908052270

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor