scholarly journals Simultaneous Enantiomeric Separation of Carfentrazone-Ethyl Herbicide and Its Hydrolysis Metabolite Carfentrazone by Cyclodextrin Electrokinetic Chromatography. Analysis of Agrochemical Products and a Degradation Study

Molecules ◽  
2021 ◽  
Vol 26 (17) ◽  
pp. 5350
Author(s):  
Laura García-Cansino ◽  
María Ángeles García ◽  
María Luisa Marina
Keyword(s):  
Enantiomeric Separation ◽  
Chiral Selector ◽  
Electrokinetic Chromatography ◽  
Reverse Polarity ◽  
Degradation Study ◽  
Chromatography Analysis ◽  
Simultaneous Separation ◽  
Individual Determination ◽  
The Individual

The different activity and toxicity that the enantiomers of agrochemicals may have requires the development of stereoselective analytical methodologies enabling the individual determination of each enantiomer. The aim of this work was to develop the first Electrokinetic Chromatography methodology enabling the simultaneous enantiomeric separation of carfentrazone-ethyl herbicide and its hydrolysis metabolite carfentrazone. The use of an anionic cyclodextrin as chiral selector (captisol at 2.5% (w/v)) in a 25 mM acetate buffer, at a temperature of 30 °C, and an applied voltage (reverse polarity) of −30 kV, allowed the simultaneous separation of the four enantiomers of the two compounds studied in 6.8 min with enantiomeric resolutions of 5.0 for carfentrazone-ethyl and 5.1 for carfentrazone. Analytical characteristics of the developed method were evaluated and found adequate to achieve the quantitation of carfentrazone-ethyl and carfentrazone. Analysis of a commercial herbicide formulation showed the potential of the method for the quality control of these agrochemical products. Degradation studies for carfentrazone-ethyl revealed that no significant degradation took place in cleaned sand samples while a significant but not stereoselective degradation took place in soils for the whole period of time considered (seven days).

Liquid Chromatographic Determination of Cinnamic and Benzoic Acids in Benzoin Preparations

1987 ◽  
Vol 70 (4) ◽  
pp. 689-691
Author(s):  
Abdel-Aziz M Wahbi ◽  
Mohammad A Abounassif ◽  
El-Rasheed A Gad-Kariem ◽  
Mahmoud W Ibrahim
Keyword(s):  
Chromatographic Determination ◽  
Cinnamic Acids ◽  
Reverse Phase ◽  
British Pharmacopoeia ◽  
Liquid Chromatographic Method ◽  
Individual Determination ◽  
Liquid Chromatographic Determination ◽  
The Individual ◽  
Liquid Chromatographic

Abstract A liquid chromatographic method for the individual determination of benzoic and cinnamic acids in 2 benzoin preparations is presented. The method specifies a reverse phase column and 0.01M KH2P04- methanol (85 + 15) as mobile phase at a flow rate of 1.8 mL/min, with detection at 254 nm. The method has been applied to 2 benzoin preparations and the results were compared with those from the British Pharmacopoeia method.

scholarly journals Chiral Monolithic Silica-Based HPLC Columns for Enantiomeric Separation and Determination: Functionalization of Chiral Selector and Recognition of Selector-Selectand Interaction

Molecules ◽  
2021 ◽  
Vol 26 (17) ◽  
pp. 5241
Author(s):  
Mufarreh Asmari ◽  
Xiaoyu Wang ◽  
Natalia Casado ◽  
Marjan Piponski ◽  
Sergiy Kovalenko ◽  
...  
Keyword(s):  
Enantiomeric Separation ◽  
Chiral Selector ◽  
Covalent Functionalization ◽  
Monolithic Silica ◽  
Silica Column ◽  
Chiral Compounds ◽  
Mobile Phase Additive ◽  
Monolithic Silica Column ◽  
Impurity Determination

This review draws attention to the use of chiral monolithic silica HPLC columns for the enantiomeric separation and determination of chiral compounds. Properties and advantages of monolithic silica HPLC columns are also highlighted in comparison to conventional particle-packed, fused-core, and sub-2-µm HPLC columns. Nano-LC capillary monolithic silica columns as well as polymeric-based and hybrid-based monolithic columns are also demonstrated to show good enantioresolution abilities. Methods for introducing the chiral selector into the monolithic silica column in the form of mobile phase additive, by encapsulation and surface coating, or by covalent functionalization are described. The application of molecular modeling methods to elucidate the selector–selectand interaction is discussed. An application for enantiomeric impurity determination is also considered.

INDIVIDUAL DETERMINATION OF CORTISOL AND CORTICOSTERONE IN A SINGLE SMALL SAMPLE OF PERIPHERAL BLOOD

1961 ◽  
Vol 38 (3) ◽  
pp. 399-406 ◽  
Author(s):  
J. van der Vies
Keyword(s):  
Sulfuric Acid ◽  
Carbon Tetrachloride ◽  
Peripheral Blood ◽  
Partition Coefficients ◽  
Small Sample ◽  
Peripheral Plasma ◽  
Individual Determination ◽  
The Individual

ABSTRACT A method is described for the individual determination of corticosterone (11β,21-dihydroxy-pregn-4-ene-3,20-dione) and cortisol (11β,17,21 -trihydroxy-pregn-4-ene-3,20-dione) in 2.5 ml of peripheral plasma. The method is based on the different partition coefficients of these steroids between water and carbon tetrachloride, allowing of separation by simple extractions. The steroids are determined by reading the fluorescence in a mixture of sulfuric acid and alcohol.

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