scholarly journals Extension of the Internal Standard Method for Determination of Thermodynamic Acidity Constants of Compounds Sparingly Soluble in Water by Capillary Zone Electrophoresis

ACS Omega ◽  
2021 ◽  
Author(s):  
Lucie Nytrová ◽  
Klára Odehnalová ◽  
Jiří Pazourek
Keyword(s):  
Capillary Zone Electrophoresis ◽  
Standard Method ◽  
Internal Standard ◽  
Internal Standard Method ◽  
Acidity Constants ◽  
Zone Electrophoresis ◽  
Capillary Zone

Application of Capillary Zone Electrophoresis in the Separation and Determination of the Tertiary Butylhydroquinone

2011 ◽  
Vol 361-363 ◽  
pp. 683-686
Author(s):  
Qian Xiang ◽  
Ying Gao
Keyword(s):  
Capillary Zone Electrophoresis ◽  
Internal Standard ◽  
Amperometric Detection ◽  
Internal Standard Method ◽  
Tertiary Butylhydroquinone ◽  
Peak Intensity ◽  
Relative Standard ◽  
Zone Electrophoresis ◽  
Capillary Zone

We describe the use of capillary zone electrophoresis (CZE) for the determination of tertiary butylhydroquinone (TBHQ) without derivatization or purification. The influences of buffer pH and voltage on the separation of TBHQ were studied. The internal standard method was used for the quantification of TBHQ. Amperometric detection was carried out at an applied potential of 0.80 V. The detection limit of TBHQ was found to be 10-6 M. Peak intensity varied linearly with TBHQ concentration from 10-4 to 5×10-6 M. The relative standard deviation (RSD) for peak intensity and migration time was in the range of 3.58–4.36% and 0.51–0.94%, respectively. The recovery of the method in food samples is 95.36% for TBHQ. The method developed is suitable for the routine analysis of synthetic phenolic antioxidant TBHQ in samples.

Determination of alcohols in mixtures by 19F NMR spectroscopy using hexefluoroacetone reagent

1982 ◽  
Vol 47 (7) ◽  
pp. 1973-1978 ◽  
Author(s):  
Jiří Karhan ◽  
Zbyněk Ksandr ◽  
Jiřina Vlková ◽  
Věra Špatná
Keyword(s):  
Standard Deviation ◽  
Nmr Spectroscopy ◽  
Standard Method ◽  
Internal Standard ◽  
Internal Standard Method ◽  
Concentration Region ◽  
Experimental Conditions ◽  
Curve Method ◽  
Sample Preparation Procedure

The determination of alcohols by 19F NMR spectroscopy making use of their reaction with hexafluoroacetone giving rise to hemiacetals was studied on butanols. The calibration curve method and the internal standard method were used and the results were mutually compared. The effects of some experimental conditions, viz. the sample preparation procedure, concentration, spectrometer setting, and electronic integration, were investigated; the conditions, particularly the concentrations, proved to have a statistically significant effect on the results of determination. For the internal standard method, the standard deviation was 0.061 in the concentration region 0.032-0.74 mol l-1. The method was applied to a determination of alcohols in the distillation residue from an oxo synthesis.

Determination of puerarin in pharmaceutical and biological samples by capillary zone electrophoresis with UV detection

Talanta ◽  
2012 ◽  
Vol 91 ◽  
pp. 83-87 ◽  
Author(s):  
Lizhen Liu ◽  
Feng Feng ◽  
Shaomin Shuang ◽  
Yunfeng Bai ◽  
Martin M.F. Choi
Keyword(s):  
Capillary Zone Electrophoresis ◽  
Biological Samples ◽  
Uv Detection ◽  
Zone Electrophoresis ◽  
Capillary Zone
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