Deuterium nuclear magnetic resonance relaxation study of mobile phase-stationary phase interactions in reversed-phase high-performance liquid chromatography

1984 ◽  
Vol 56 (12) ◽  
pp. 2090-2093 ◽  
Author(s):  
David B. Marshall ◽  
William P. McKenna
Keyword(s):  
Nuclear Magnetic Resonance ◽  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Magnetic Resonance ◽  
Mobile Phase ◽  
High Performance ◽  
Reversed Phase ◽  
Nuclear Magnetic Resonance Relaxation ◽  
Relaxation Study ◽  
Resonance Relaxation

Studies on the Stereochemical Characterization of N-Methylated Amino Acids

1991 ◽  
Vol 44 (11) ◽  
pp. 1591 ◽  
Author(s):  
SG Ang ◽  
SH Low
Keyword(s):  
Amino Acids ◽  
Nuclear Magnetic Resonance ◽  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Magnetic Resonance ◽  
Mobile Phase ◽  
High Performance ◽  
1H Nuclear Magnetic Resonance ◽  
Chiral Solvating Agent

Various methods that could be used to determine the absolute configuration of N,N- dimethylated amino acids were investigated. Two methods utilizing 1H nuclear magnetic resonance (N.M.R.) spectroscopy were successful. The first involved the conversion of the N,N- dimethylated amino acids into diastereoisomers by reaction with methyl (S)-(+)- mandelate . In the second method, the N,N- dimethylated amino acids were amidated with 3,5-dinitroaniline, and 1H n.m.r. analysis was carried out with the addition of a chiral solvating agent, (R)-(-)-1-(9-anthryl)-2,2,2-trifluoroethanol [(R)-(-)-atfe ]. Another method involving the use of high-performance liquid chromatography ( h.p.l.c .), with bis (L-aspartic cyclohexylamide )copper(II) complex CuII (L- Aspchex )2, as the chiral mobile phase was also examined but was found to be unsuccessful in resolving the D- and L-isomers of N,N- dimethylated amino acids.

Separation and Determination of Some Aromatic Sulfones by Reversed-Phase High-Performance Liquid Chromatography

1994 ◽  
Vol 59 (3) ◽  
pp. 569-574 ◽  
Author(s):  
Josef Královský ◽  
Marta Kalhousová ◽  
Petr Šlosar
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Mobile Phase ◽  
High Performance ◽  
Reversed Phase ◽  
Uv Spectra ◽  
Optimum Conditions ◽  
Linear Calibration ◽  
Technical Grade

The reversed-phase high-performance liquid chromatography of some selected, industrially important aromatic sulfones has been investigated. The chromatographic behaviour of three groups of aromatic sulfones has been studied. The optimum conditions of separation and UV spectra of the sulfones and some of their hydroxy and benzyloxy derivatives are presented. The dependences of capacity factors vs methanol content in mobile phase are mentioned. The results obtained have been applied to the quantitative analysis of different technical-grade samples and isomer mixtures. For all the separation methods mentioned the concentration ranges of linear calibration curves have been determined.

4-Nitrophenol in 4-nitrophenyl phosphate, a substrate for alkaline phosphatase, as measured by paired-ion high-performance liquid chromatography.

1977 ◽  
Vol 23 (12) ◽  
pp. 2288-2291 ◽  
Author(s):  
P H Culbreth ◽  
I W Duncan ◽  
C A Burtis
Keyword(s):  
Alkaline Phosphatase ◽  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Flow Rate ◽  
Mobile Phase ◽  
High Performance ◽  
Reversed Phase ◽  
Nitrophenyl Phosphate ◽  
Phase Column ◽  
Reversed Phase Column

Abstract We used paired-ion high-performance liquid chromatography to determine the 4-nitrophenol content of 4-nitrophenyl phosphate, a substrate for alkaline phosphatase analysis. This was done on a reversed-phase column with a mobile phase of methanol/water, 45/55 by vol, containing 3 ml of tetrabutylammonium phosphate reagent per 200 ml of solvent. At a flow rate of 1 ml/min, 4-nitrophenol was eluted at 9 min and monitored at 404 nm; 4-nitrophenyl phosphate was eluted at 5 min and could be monitored at 311 nm. Samples of 4-nitrophenyl phosphate obtained from several sources contained 0.3 to 7.8 mole of 4-nitrophenol per mole of 4-nitrophenyl phosphate.

Sign in / Sign up

Export Citation Format

Share Document