Liquid chromatographic analysis and isolation of diastereoisomers obtained by an aldolization reaction

1995 ◽  
Vol 73 (10) ◽  
pp. 1733-1737 ◽  
Author(s):  
Michel Lafosse ◽  
Philippe Morin ◽  
Christophe Anceau ◽  
Gérard Coudert ◽  
Gérald Guillaumet ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Reaction Mechanism ◽  
Chromatographic Analysis ◽  
Normal Phase ◽  
Structural Determination ◽  
Mobile Phases ◽  
Liquid Chromatographic Analysis ◽  
Phase Liquid ◽  
Liquid Chromatographic

A new route using an aldolization reaction has been investigated in order to synthesize a precursor of pilocarpin, an alkaloid having sympathomimetic properties. To study the stereoselectivity of this route and to propose a mechanism, liquid chromatography has been used to analyse and to isolate each diastereoisomer for a structural determination by NMR. To further investigate the reaction mechanism, seven different aldehydes (or ketones) were used in the aldolization reaction, producing seven different mixtures. This paper describes the improvement of LC conditions with diol- and amino-bonded silica and the nonaqueous mobile phases required for the isolation of each isomer. Keywords: diastereoisomers, pilocarpin precursor, normal phase liquid chromatography, diol- and amino-bonded silicas.

Nonaqueous Reverse Phase Liquid Chromatographic Analysis for Cholesterol in Milk Chocolate

1984 ◽  
Vol 67 (4) ◽  
pp. 698-700
Author(s):  
W Jeffrey Hurst ◽  
Michael D Aleo ◽  
Robert A Martin
Keyword(s):  
Liquid Chromatography ◽  
Chromatographic Analysis ◽  
Mobile Phase ◽  
Direct Detection ◽  
Reverse Phase ◽  
Milk Chocolate ◽  
Liquid Chromatographic Analysis ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract A method using liquid chromatography was developed for the analysis of cholesterol in milk chocolate products. The method involves saponification of the sample with methanolic KOH followed by extraction with ether. Potentially interfering components are eliminated through the use of a silica Sep-Pak cleanup step before injection. The nonaqueous reverse phase LC system consists of a C18 column and an isopropanol- hexane mobile phase with direct detection at 205 nm. Recoveries of 1, 3, and 5 mg cholesterol added to 1 g sample of milk chocolate were 88.6, 102.8, and 110.1%, respectively. Studies conducted with [4-14C]-cholesterol were undertaken to further document the accuracy of the method.

Application of "high-performance" liquid chromatography to the study of sphingolipidoses.

1980 ◽  
Vol 26 (10) ◽  
pp. 1499-1503 ◽  
Author(s):  
M D Ullman ◽  
R E Pyeritz ◽  
H W Moser ◽  
D A Wenger ◽  
E H Kolodny
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Plasma Exchange ◽  
Chromatographic Analysis ◽  
High Performance ◽  
High Performance Liquid Chromatographic ◽  
Reversed Phase ◽  
Urine Sediment ◽  
Liquid Chromatographic Analysis ◽  
Liquid Chromatographic

Abstract Quantitative high-performance liquid chromatographic analysis of perbenzoylated sphingolipids has been used to study the correlations of body chemistry to clinical phenomena. Plasma sphingolipids were isolated from 32 Gaucher (β-glucosidase deficiency) and six Fabry (α-galactosidase deficiency) patients by solvent partition and chromatographic separation on silicic acid columns. Plasma sphingolipids from a patient undergoing plasma-exchange were separated from interfering lipids with reversed-phase columns. Liquid-chromatographic analysis of sphingolipids provides useful supportive information for diagnoses because affected individuals are shown to possess increased circulating concentrations of the pathognomonic sphingolipid. We also used this technique to monitor sphingolipid concentrations in plasma and urine sediment during plasma exchange of a p atient with Fabry’s disease. Regular plasma exchanges produced and maintained decreased concentrations of sphingolipids in plasma, but near pre-exchange concentrations were observed within days after the therapy was terminated.

Liquid Chromatographic Method for Determination of Cyfluthrin in Technical and Formulated Products

1990 ◽  
Vol 73 (4) ◽  
pp. 595-598
Author(s):  
Stephen C Slahck
Keyword(s):  
Liquid Chromatography ◽  
Chromatographic Method ◽  
Internal Standard ◽  
Normal Phase ◽  
Liquid Chromatographic Method ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract A liquid chromatographic method for determination of cyfluthrin (Baythrold®, Tempo®) diastereomers In technical and formulated products has been developed. Samples are dissolved in dloxane-hexane and analyzed by normal-phase liquid chromatography using acetophenone as an internal standard. The method Is applicable to technical Baythrold, Baythrold 2 EC, Tempo 20 WP, and granular formulations. The method separates all 4 diastereomers of cyfluthrin and all impurities in less than 19 mln.

Dissolvable Mg/Al layered double hydroxides and surfactant as an extractant for trace analysis of benzoylurea insecticides by high performance liquid chromatography

2020 ◽  
Vol 12 (44) ◽  
pp. 5380-5391
Author(s):  
Yanawath Santaladchaiyakit ◽  
Supalax Srijaranai
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Chromatographic Analysis ◽  
High Performance ◽  
High Performance Liquid Chromatographic ◽  
Liquid Chromatographic Analysis ◽  
Benzoylurea Insecticides ◽  
Double Hydroxides ◽  
Liquid Chromatographic ◽  
Preconcentration Method

A simple and rapid preconcentration method using dissolvable Mg/Al LDHs and SDS has been demonstrated for high performance liquid chromatographic analysis of benzoylurea insecticides in water and honey samples.

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