Results 111 to 120 of about 951 (168)

Isolation of coffee diterpenes by means of high-speed countercurrent chromatography

Journal of Food Composition and Analysis, 2009
Abstract Many different physiological activities have been ascribed to coffee diterpenes, such as cholesterol increasing activity for the diterpenes kahweol and cafestol. Another member of this class, namely the diterpene 16-O-methylcafestol, is used as a marker substance for robusta coffee.
Peter Winterhalter
exaly   +2 more sources

High-Speed Countercurrent Chromatography

Critical Reviews in Analytical Chemistry, 1986
I. INTRODUCTION During the past 20 years countercurrent chromatography (CCC) has been steadily improved in both partition efficiency and separation times.1-15 The original helix CCC and the successively developed nonhelix preparative-scale CCC schemes, such as droplet CCC16,17 and locular CCC,17 required relatively long separating times; sizeable ...
Yoichiro Ito, Walter D. Conway
openaire   +1 more source

Chiral Separation by High-Speed Countercurrent Chromatography

Analytical Chemistry, 1995
Various parameters involved in the chiral separation of (+/-)-DNB-amino acids were investigated using N-dodecanoyl-L-proline-3,5-dimethylanilide as a chiral selector (CS) and two-phase solvent systems composed of hexane/ethyl acetate/methanol/10 mM hydrochloric acid at various volume ratios.
Y, Ma, Y, Ito
openaire   +2 more sources

Development of High-Speed Countercurrent Chromatography

2021
The preparative capability of the multilayer coil has been demonstrated in the separation of 1 g of the DNP amino acid mixture under the optimal operational conditions determined by the preliminary studies on short coils as described above. These centrifuge schemes are equipped with a novel flow-through mechanism which entirely eliminates the need for ...
openaire   +2 more sources

Analytical High Speed Countercurrent Chromatography

Journal of Liquid Chromatography, 1988
Abstract The resolution of countercurrent distribution has long been demonstrated. However, the long elution time limits its analytical applications. The development of a high speed planet centrifuge has markedly improved the efficiency of the system; thus the countercurrent chromatography can be completed within several hours instead of days.
Y.-W. Lee, Y. Ito, Q.-C. Fang, C. E. Cook   +3 more
openaire   +1 more source

Retention of the stationary phase for high‐speed countercurrent chromatography

AIChE Journal, 2007
AbstractHigh‐speed countercurrent chromatography (HSCCC) is an emerging technique for preparative purification of a wide variety of solutes. Retention of the stationary phase is a crucial variable which is used for the derivation of the column efficiency, peak resolution, and solute retention.
He, Chao-Hong, Zhao, Chun-Xia
openaire   +3 more sources

PURIFICATION OF YTTRIUM BY HIGH-SPEED COUNTERCURRENT CHROMATOGRAPHY

Journal of Liquid Chromatography & Related Technologies, 1999
Separation of rare earth elements has been studied by high– speed countercurrent chromatography (CCC) employing 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester in toluene as a stationary phase. The CCC method was applied to purification of rare earth elements in a wide range of concentrations. High-purity yttrium was chromatographically isolated by
Shigeto Nakamura, Hiroyuki Hashimoto, Kenichi Akiba   +2 more
openaire   +1 more source

High-speed countercurrent chromatography

Nature, 1987
Support-free high-speed countercurrent liquid chromatography provides a rich domain of applications, some beyond reach of conventional liquid chromatography.
openaire   +2 more sources

Mass transfer and separation criteria for high‐speed countercurrent chromatography

AIChE Journal, 2011
AbstractHigh‐speed countercurrent chromatography (HSCCC) is a versatile technique for preparative separations of a wide variety of solutes. For optimization of operating conditions, prediction of separations, and scale‐up study, a model is needed to describe the effluent concentration profile, which determines the separation efficiency (mass transfer ...
Zhao, Chun-Xia, He, Chao-Hong
openaire   +3 more sources

Purification of Curcumin, Demethoxycurcumin, and Bisdemethoxycurcumin by High-Speed Countercurrent Chromatography

Journal of Agricultural and Food Chemistry, 2008
Curcuminoids are substances of great interest because of their important pharmacological activities, particularly anti-inflammatory, anticarcinogenic, and anti-Alzheimer's activities. In this study, we report the first procedure and effect of processing for the high, efficient, and useful purification of curcumin, demethoxycurcumin, and ...
Koichi, Inoue, Chihiro, Nomura, Sumio, Ito, Akito, Nagatsu, Tomoaki, Hino, Hisao, Oka   +5 more
openaire   +2 more sources