Determination of 9-fluorenylmethoxycarbonyl (Fmoc) resin loading in solid‐phase synthesis by RP-HPLC internal standard method

2021 ◽  
Author(s):  
Hynek Mácha ◽  
Marek Kořínek ◽  
Ladislav Drož ◽  
Karel Nesměrák
Keyword(s):  
Standard Method ◽  
Solid Phase Synthesis ◽  
Solid Phase ◽  
Internal Standard ◽  
Internal Standard Method ◽  
Phase Synthesis ◽  
Rp Hplc ◽  
Resin Loading

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.

scholarly journals Validation of an HPLC method for the simultaneous determination of eletriptan and UK 120.413

2006 ◽  
Vol 71 (11) ◽  
pp. 1195-1205 ◽  
Author(s):  
Mira Zecevic ◽  
Biljana Jocic ◽  
Snezana Agatonovic-Kustrin ◽  
Ljiljana Zivanovic
Keyword(s):  
Mobile Phase ◽  
Analytical Procedure ◽  
Internal Standard ◽  
Correlation Coefficients ◽  
Hplc Method ◽  
Control Analysis ◽  
Internal Standard Method ◽  
Rp Hplc ◽  
Good Repeatability

Arapid and sensitive RPHPLCmethod was developed for the routine control analysis of eletriptan hydrobromide and its organic impurity UK 120.413 in Relpax? tablets. The chromatography was performed at 20?C using a C18 XTerra ? (5 ?m, 150 x 4,6 mm) column at a flow rate 1.0 ml/min. The drug and its impurity were detected at 225 nm. The mobile phase consisted of TEA (1 %) - methanol (67.2:32.8 v/v), the pH of which was adjusted to 6.8 with 85 % orthophosphoric acid. Quantification was accomplished by the internal standard method. The developed RP HPLC method was validated by testing: accuracy, precision, repeatability, specificity, detection limit, quantification limit, linearity, robustness and sensitivity. High linearity of the analytical procedure was confirmed over the concentration range of 0.05 - 1.00 mg/ml for eletriptan hydrobromide and from 0.10 - 1.50 ?g/ml for UK 120.413, with correlation coefficients greater than r = 0.995. The low value of the RSD expressed the good repeatability and precision of the method. Experimental design and a response surface method were used to test robustness of the analytical procedure and to evaluate the effect of variation of the method parameters, namely the mobile phase composition, pH and temperature. They showed small deviations from the method setting. The good recovery and low RSD confirm the suitability of the proposed RP HPLC method for the routine determination of eletriptan hydrobromide and its impurity UK 120.413 in Relpax? tables.

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