1. Enantioselective analysis of proteinogenic amino acids in cerebrospinal fluid by capllary electrophoresis-mass spectrometry
- Author
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Prior, Amir, Sánchez-Hernández, Laura, Sastre-Toraño, Javier, Marina, Maria Luisa, de Jong, Gerhardus J., Somsen, Govert W., Biomolecular Analysis, Afd Chemical Biology and Drug Discovery, Sub Biomolecular analysis, BioAnalytical Chemistry, and AIMMS
- Subjects
Electrospray ,phenylalanine ,Clinical Biochemistry ,isoleucine ,arginine ,01 natural sciences ,Biochemistry ,Capillary electrophoresis–mass spectrometry ,Mass Spectrometry ,Analytical Chemistry ,chemistry.chemical_compound ,pressure ,valine ,Limit of Detection ,derivatization ,nebulizer gas pressure ,linear system ,proline ,Amino Acids ,cysteine ,chemistry.chemical_classification ,pH ,article ,asparagine ,Stereoisomerism ,Amino acid ,unclassified drug ,glutamine ,flow rate ,alanine ,glutamic acid ,leucine ,amino acid ,capillary electrophoresis ,2 propanol ,010402 general chemistry ,Mass spectrometry ,cerebrospinal fluid ,serine ,Capillary electrophoresis ,enantioselectivity ,chemical composition ,tryptophan ,controlled study ,chemical compound ,Derivatization ,Detection limit ,methionine ,Chromatography ,lysine ,ammonium bicarbonate ,concentration (parameters) ,010401 analytical chemistry ,temperature ,Electrophoresis, Capillary ,Reproducibility of Results ,histidine ,calibration ,Chiral separation ,threonine ,0104 chemical sciences ,Ammonium bicarbonate ,chemistry ,aspartic acid ,measurement repeatability ,Spectrophotometry, Ultraviolet ,electrospray ,tyrosine ,glycine - Abstract
d-Amino acids (AAs) are increasingly being recognized as essential molecules in biological systems. Enantioselective analysis of proteinogenic AAs in biological samples was accomplished by CE-MS employing β-CD as chiral selector and ESI via sheath-liquid (SL) interfacing. Prior to analysis, AAs were fully derivatized with FMOC, improving AA-enantiomer separation and ESI efficiency. In order to optimize the separation and MS detection of FMOC-AAs, the effects of type and concentration of CD in the BGE, the composition of the SL, and MS-interfacing parameters were evaluated. Using a BGE of 10 mM β-CD in 50 mM ammonium bicarbonate (pH 8) containing 15% v/v isopropanol, a SL of isopropanol-water-1 M ammonium bicarbonate (50:50:1, v/v/v) at a flow rate of 3 μL/min, and a nebulizer gas pressure of 2 psi, 15 proteinogenic AAs could be detected with enantioresolutions up to 3.5 and detection limits down to 0.9 μM (equivalent to less than 3 pg AA injected). The selectivity of the method was demonstrated by the analysis of spiked cerebrospinal fluid, allowing specific detection of d-AAs. Repeatability and linearity obtained for cerebrospinal fluid were similar to standard solutions, with peak area and migration-time RSDs (n = 5) below 16.2 and 1.6%, respectively, and a linear response (R(2) ≥ 0.977) in the 3-90 μM range.
- Published
- 2016
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