Enantioseparation of FMOC-amino acids using an O-[2-(methacryloyloxy)-ethylcarbamoyl]-10,11-dihydroquinidine-silica hybrid monolithic column by nano-LC. Quantitation of lL-norvaline and lL-tryptophan in dietary supplements

Publication date: Available online 23 October 2019Source: Journal of Pharmaceutical AnalysisAuthor(s): Dongsheng Xu, Elena Sánchez-López, Qiqin Wang, Zhengjin Jiang, María Luisa MarinaAbstractAn analytical methodology based on an O-[2-(methacryloyloxy)-ethylcarbamoyl]-10,11-dihydroquinidine (MQD)-silica hybrid monolithic column was developed for the enantioseparation of 9-fluorenylmethoxycarbonyl (FMOC) derivatized amino acids by nano-liquid chromatography. The mobile phase was optimized including the apparent pH, content of ACN, and concentration of the buffer to obtain a satisfactory enantioresolution performance. 27 FMOC derivatized amino acids including 19 protein and 8 non-protein amino acids were tested, and 19 out of them were enantiomerically discriminated obtaining baseline separation for 11 of them. Analytical characteristics of the method were evaluated for norvaline and tryptophan in terms of linearity, precision, accuracy, limits of detection (LOD) and quantitation (LOQ) showing good performance to be applied to the enantiomeric determination of these amino acids in dietary supplements. LOD and LOQ values were 9.3 and 31 μM for norvaline enantiomers and 7.5 and 25 μM for tryptophan enantiomers, respectively. The contents of dD-norvaline and dD-tryptophan were below their respective LODs in all the analyzed samples. Quantitation of lL-tryptophan and lL-norvaline showed good agreement with the labeled contents except for one sample which did not show prese...
Source: Journal of Pharmaceutical Analysis - Category: Drugs & Pharmacology Source Type: research