Retention/quantitation properties of the o-phthaldialdehyde–3-mercaptopropionic acid and the o-phthaldialdehyde–N-acetyl-l-cysteine amino acid derivatives in reversed-phase high-performance liquid chromatography

Advancement in the derivatizations of the amino groups with the o-phthaldehyde-thiol and with the 9-fluorenylmethyloxycarbonyl chloride reagents

“…Certainly these two derivatization protocols did have and they still have their uncertainties, limitations, shortages and advantages: however, in the last decade the overwhelming part of uncertainties were examined and cleared up: resulting in the trouble-free, conscious and reliable use the OPA [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] and that of the FMOC [20,21] techniques, as well.…”

“…(3) What is the storage time of the OPA reagents until providing optimum responses? (4) What is the reason of the virtual instability of the glycine, ␤-alanine, ␥-aminobutyric acid (GABA), histidine, ornithine, lysine and primary amine derivatives, in comparison to the rest of AAs? (5) What is the UV/FL optimum of the isoindoles and how are these affected by the molar ratios of OPA/thiol?…”

“…In order to get answer to these questions in author's laboratory two approaches were followed: stoichiometric investigations were carried out with simultaneous PDA and FL detections [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] while structure elucidation were confirmed by on line HPLC/PDA/mass spectrometry (MS) applying electro spray ionization (ESI) in the positive mode [7,12,13,15]. The literature contains a variety of contradictory conditions regarding derivatization conditions.…”

Simple and rapid quantitative high-performance liquid chromatographic analysis of plasma amino acids

“…[9] Previous studies have demonstrated that the formation of OPA derived fluorescent amino compounds are more stable in the presence of the thiol 3-mercaptopropionic acid (MPA) instead of the more commonly used 2-mercaptoethanol. [10][11][12] In this manuscript we describe a simple and rapid automatic online precolumn derivatization HPLC method for the quantitation of plasma amino acids. The separation of the amino acid derivatives is by reversed-phase chromatography and quantitation by fluorescent detection.…”

Photodecomposition of o-phthaldialdehyde-derivatized amino acids by the photodiode array detector during their high-performance liquid chromatographic analysis

“…Most of these methods include reversed phase high-performance liquid chromatographic (HPLC) separations of the pre-column-derivatized amino acids using UV and/or fluorescence and/or MS detections [7][8][9][10][11][12]. Because of the simplicity and reproducibility of the method and due to the UV and high fluorescent sensitivity of the derivatized amino acids, pre-column modification of these compounds with ophthaldialdehyde (OPA) [13] in the presence thiol derivatives such as 2-mercaptoethanol (2-ME), 3-mercaptopropionic acid (3-MPA) or N-acetyl-L-cysteine (NAC) have become the most popular and widely accepted method for the determination of amino acids originating from biological samples [7][8][9][10][11][12]. The effect of the reaction conditions such as pH, temperature and the ratio of reactant concentrations on the stability of a wide range of OPA-derivatized amino acids (in the presence of 2-ME and 3-MPA) have been thoroughly studied [11,12].…”