Determination of delta-aminobutyric acid and other amino acids in cerebrospinal fluid of pediatric patients by reversed-phase liquid chromatography.

1987 ◽  
Vol 33 (10) ◽  
pp. 1736-1740 ◽  
Author(s):  
R F Goldsmith ◽  
J W Earl ◽  
A M Cunningham
Keyword(s):  
Amino Acids ◽  
Cerebrospinal Fluid ◽  
Pediatric Patients ◽  
Reference Intervals ◽  
Reversed Phase ◽  
Aminobutyric Acid ◽  
Control Group ◽  
Precolumn Derivatization ◽  
Gamma Aminobutyric Acid ◽  
Phase Liquid

Abstract The reversed-phase liquid-chromatographic system described here is capable of resolving the neurotransmitter amino acids aspartic acid, glutamic acid, and gamma-aminobutyric acid (GABA) plus 21 other amino acids in cerebrospinal fluid (CSF) in a single analysis. The amino acids, derivatized with o-phthalaldehyde, are separated in 65 min. Concentrations of glutamine less than or equal to 600 mumol/L can be measured at the same time as GABA greater than or equal to 10 nmol/L. Using this method, we have determined reference intervals for amino acids, including GABA, in CSF in a group of pediatric patients who underwent lumbar puncture before myelography, and who were subsequently shown to have normal myelograms. These intervals are generally lower than those previously reported for childhood, but we believe this results from a more rigid selection of the control group. In addition, artifactual increases in concentrations of free neurotransmitters, caused by breakdown of amino acid conjugates, are minimized by (a) immediate freezing of the CSF samples to prevent enzyme-mediated changes, (b) omission of a deproteinization step, and (c) precolumn derivatization to reduce on-column breakdown of amide and peptide forms.

Isocratic HPLC assay with electrochemical detection of free gamma-aminobutyric acid in cerebrospinal fluid

1993 ◽  
Vol 39 (2) ◽  
pp. 247-250 ◽  
Author(s):  
A B Naini ◽  
E Vontzalidou ◽  
L J Côté
Keyword(s):  
Cerebrospinal Fluid ◽  
Electrochemical Detection ◽  
Reversed Phase ◽  
Aminobutyric Acid ◽  
Precolumn Derivatization ◽  
Gamma Aminobutyric Acid ◽  
Electrochemical Detector ◽  
Three Samples ◽  
Coefficients Of Variation ◽  
Isocratic Hplc

Abstract A method for measuring gamma-aminobutyric acid (GABA) in human cerebrospinal fluid (CSF) by isocratic HPLC with electrochemical detection is described. The method is based on precolumn derivatization of GABA with o-phthaldialdehyde (OPA) and tert-butylthiol (t-BT), separation of the GABA-OPA complex on a reversed-phase column, and quantitation by means of a Coulochem electrochemical detector. The method is highly sensitive and specific for GABA. In three samples of human CSF containing low, medium, and high amounts of GABA, the coefficients of variation between and within runs were 4.5% and 3.6%, respectively. The concentration of GABA in 10 neurologically intact subjects was 92.5 +/- 9.4 nmol/L of CSF.

Reversed-Phase Liquid Chromatographic Determination of Hypoglycin A (HG-A) in Canned Ackee Fruit Samples

1994 ◽  
Vol 77 (5) ◽  
pp. 1175-1179 ◽  
Author(s):  
Ghulam Sarwar ◽  
Herbert G Botting
Keyword(s):  
Amino Acids ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Precolumn Derivatization ◽  
Edible Portion ◽  
Fruit Samples ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract A reversed-phase liquid chromatographic (LC) method involving precolumn derivatization with phenylisothiocyanate (PITC) was developed for determining levels of hypoglycin A (HG-A) in canned ackee fruit samples. HG-A was extracted by homogenizing the drained fruit in 80% ethanol. By using a Waters Pico-Tag amino acid analysis 15-cm-long column (which is also used for analyzing protein hydrolysates and biological samples) and an LC system, the baseline separation of HG-A from other amino acids was completed in about 6 min. The total time for analysis and equilibration was 16 min. HG-A levels in the edible portion of fruit in 18 cans varied from 18.27 to 87.50 mg HG-A/can. Recoveries of added standard HG-A averaged 101%. To our knowledge, this is the first report of the use of this method to determine HG-A in ackee fruit.

Determination of Amino Acids in Food and Feed by Derivatization with 6-Aminoquinolyl-N-Hydroxysuccinimidyl Carbamate and Reversed-Phase Liquid Chromatographic Separation

1995 ◽  
Vol 78 (3) ◽  
pp. 736-743 ◽  
Author(s):  
Hong Ji Liu ◽  
Bi Ying Chang ◽  
Hui Wen Yan ◽  
Feng Hua Yu ◽  
Xing Xiang Liu
Keyword(s):  
Amino Acids ◽  
Reversed Phase ◽  
Exchange Chromatography ◽  
Cysteic Acid ◽  
Precolumn Derivatization ◽  
Methionine Sulfone ◽  
Relative Standard ◽  
Food And Feed ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract A study of a new amino acid analysis method using 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate as a precolumn derivatization reagent for the analysis of food and feed is described. All amino acids, including methionine sulfone and cysteic acid, were well separated on a liquid chromatographic system using the optimized chromatographic conditions. Salts in food and feed interfered very slightly with the derivatization yields of all amino acids. Several typical agricultural products and animal feeds, including 2 AOAC test samples, were analyzed with the method. The results agreed well with the data generated by using the classical postcolumn method with ion-exchange chromatography. The average relative standard deviations for corn and broiler starter feed were 0.74 and 0.70%, respectively. Good recoveries of all amino acids were demonstrated (average, 101%), even for a sample with a very complex matrix.

Purification of Antihemophilic Factor (Factor VIII) by Amino Acid Precipitation*

1964 ◽  
Vol 11 (01) ◽  
pp. 064-074 ◽  
Author(s):  
Robert H Wagner ◽  
William D McLester ◽  
Marion Smith ◽  
K. M Brinkhous
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Factor Viii ◽  
Plasma Protein ◽  
Acid Precipitation ◽  
Aminobutyric Acid ◽  
Gamma Aminobutyric Acid ◽  
Specific Procedure ◽  
Beta Alanine ◽  
Antihemophilic Factor

Summary1. The use of several amino acids, glycine, alpha-aminobutyric acid, alanine, beta-alanine, and gamma-aminobutyric acid, as plasma protein precipitants is described.2. A specific procedure is detailed for the preparation of canine antihemophilic factor (AHF, Factor VIII) in which glycine, beta-alanine, and gammaaminobutyric acid serve as the protein precipitants.3. Preliminary results are reported for the precipitation of bovine and human AHF with amino acids.

scholarly journals An Identification and Study of Amino Acids of Erigeron annuus Herb

2021 ◽  
Vol 16 (2) ◽  
pp. 88-92
Author(s):  
S. Kovalev ◽  
A. Golovach ◽  
V. Kovalev
Keyword(s):  
Amino Acids ◽  
Liquid Chromatography ◽  
High Performance ◽  
Total Content ◽  
Amino Acid Profile ◽  
Reversed Phase ◽  
Raw Material ◽  
Precolumn Derivatization ◽  
Amino Acids Composition ◽  
Erigeron Annuus

Amino acids in the extract of Erigeron annuus herb were determined using an automatic precolumn derivatization with fluorenylmethyl-chloroformate and reversed-phase liquid chromatography with fluorescence and UV Vis detection. This objective is reached with automatic derivatization using o-phthalaldehyde (OPA) for primary amino acids and 9-Fluorenylmethyl chloroformate (FMOC) for secondary amino acids. Then derivatization integrates into high performance liquid chromatography (HPLC). The applied procedure is fast with easily reproduced results. The insufficient knowledge about amino acids composition of herb of Erigeron annuus is the basis for study. This work reports on content of 16 free and bound amino acids (391.41 μg/mg) in the plant raw material and influence’s evaluation of different extraction types on the amino acid profile. The total content of free amino acids was 4.66 μg/mg; proline prevailed (2.498 μg/mg). The total content of bound amino acids was 386.7 μg/mg; proline (146.8 μg/mg), arginine (67.8 μg/mg), phenylalanine (25.8 μg/mg), asparagine (24.3 μg/mg), histidine (20.4 μg/mg), alanine (18.2 μg/mg), serine (16.6 μg/mg), valine (16.0 μg/mg) were the dominant amino acids. Nine amino acids were classified as essential.

scholarly journals Quantification By Gas Chromatography of the Content of Amino Acids Present in Sausages Fortified with Quinoa Vegetable Protein

2021 ◽  
Author(s):  
A. Zavala ◽  
M. González ◽  
P. Pino
Keyword(s):  
Amino Acids ◽  
Gas Chromatography ◽  
Amino Acid ◽  
Vegetable Protein ◽  
Amino Acid Profile ◽  
Aminobutyric Acid ◽  
Precolumn Derivatization ◽  
Proportional Relationship ◽  
Quinoa Flour

The objective of this research was to determine the quality of the protein present in sausages fortified with quinoa as a substitute for animal protein, through the identification and quantification of amino acids, using gas chromatography and precolumn derivatization. The amino acid composition found in the analyzed products was predominantly composed of: Threonine (THR) with a concentration of 1046.32µmol / L, aminobutyric acid (ABA) with a concentration of 9685.68 µmol / L and glutamic acid (GLU) with a concentration of 1178.71 µmol / L. These values were found in the treatment with the highest percentage of quinoa flour, establishing a directly proportional relationship between the concentrations of these amino acids and the percentage of quinoa. Gas chromatography was an adequate technique for determining the amino acid profile due to its speed and sensitivity. Keywords: amino acids, sausages, quinoa, derivatization, gas chromatography. RESUMEN La presente investigación tiene por objetivo determinar la calidad de la proteína presente en embutidos fortificados con quinua como sustituyente de la proteína animal, a través de la identificación y cuantificación de aminoácidos mediante la aplicación de cromatografía de gases y la derivatización precolumna. La composición de aminoácidos encontrada en los productos analizados destaca la presencia mayoritaria de: Treonina (THR) con una concentración de 1046,32 µmol/L, ácido aminobutírico (ABA) con una concentración de 9685,68 µmol/L  y ácido glutámico (GLU) con una concentración de 1178,71 µmol/L, todos estos valores se presentaron en el tratamiento con mayor porcentaje de harina de quinua estableciéndose una relación directamente proporcional entre las concentraciones de estos aminoácidos y el porcentaje de adición de quinua en los tratamientos estudiados. Se puede concluir que la cromatografía de gases empleada resultó una técnica adecuada para la determinación del perfil aminoacídico por la rapidez y sensibilidad presentada sobre las muestras estudiadas.  Palabras claves: aminoácidos, embutidos, quinua, derivatización, cromatografía de gases.  

Separation of Proteic Primary Amino Acids under Several Reversed‐Phase Liquid Chromatographic Conditions

2006 ◽  
Vol 29 (17) ◽  
pp. 2521-2536 ◽  
Author(s):  
V. Concha‐Herrera ◽  
J. R. Torres‐Lapasió ◽  
G. Vivó‐Truyols ◽  
M. C. García‐Álvarez‐Coque
Keyword(s):  
Amino Acids ◽  
Reversed Phase ◽  
Primary Amino ◽  
Phase Liquid ◽  
Liquid Chromatographic
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