DETERMINATION OF ASPARAGINE, GLUTAMINE AND CITRULLINE IN AQUEOUS SOIL EXTRACTS WITH AN AUTOMATIC AMINO ACID ANALYZER

1968 ◽  
Vol 48 (3) ◽  
pp. 349-354 ◽  
Author(s):  
F. J. Sowden ◽  
K. C. Ivarson
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
The Other ◽  
Automatic Amino Acid Analyzer ◽  
Soil Extracts ◽  
Amide Hydrolysis ◽  
Amino Acid Analyzer ◽  
Lithium Citrate ◽  
The Common

A system of separating asparagine, glutamine and citrulline from each other and from the other common amino acids, using lithium buffers and the Technicon amino acid analyzer and C2 resin in a 0.63 × 75-cm column, is described. The column was operated with a buffer flow rate of 37 ml/hour at 30 °C for the first 70 min, then at 50 °C. The buffer was 0.067 M in lithium citrate and adjusted to a pH of 2.80; 2% isopropanol was added to improve the separation of threonine and serine. The analysis was complete through citrulline in 4 hours. If a second buffer, pH 4.15, 0.25 N in lithium was added after 3.5 hours, most of the common acidic and neutral amino acids found in soil extracts were separated in 6 hours. Some data on the determination of asparagine and glutamine by amide hydrolysis is included.

scholarly journals Determination of Methylated Basic Amino Acids with the Amino Acid Analyzer

1973 ◽  
Vol 248 (7) ◽  
pp. 2387-2391 ◽  
Author(s):  
Gladys E. Deibler ◽  
Russell E. Martenson
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Basic Amino Acids ◽  
Amino Acid Analyzer

Determination of total proteinogenic amino acids and taurine by pre-column derivatisation and UHPLC: Single Laboratory Validation, First Action 2019.09

2020 ◽  
Author(s):  
George Joseph ◽  
Asha Varughese ◽  
Ann Daniel
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Infant Formula ◽  
Retention Time ◽  
Sulfonic Acid ◽  
Internal Standard ◽  
The Other ◽  
Method Performance ◽  
Single Laboratory

Abstract Background A method has been developed and validated for selective, accurate and precise determination of total proteinogenic amino acids and taurine from Infant Formula and Adult/Pediatric Nutritional Formulas (powders, ready-to-feed liquids, and liquid concentrates). The method was reviewed by the AOAC INTERNATIONAL SPIFAN Expert Review Panel (ERP) during the 133rd AOAC Annual Meeting & Expo on September 7, 2019 in Denver, CO, USA and was recommended to First Action Official MethodsSM status. Objective The method involves protein hydrolysis to amino acids, a simple pre-column derivatisation of amino acids and separation of derivatised amino acids by UHPLC. The quantification of amino acids is performed by multi-point calibration using norvaline as the internal standard. The analytical method is capable of quantitative determination for 22 proteinogenic amino acids, but cannot be used to quantitate tryptophan, which is destroyed during the acid hydrolysis step. Asparagine is determined as aspartic acid and glutamine as glutamic acid. The cystine and cysteine are converted to S-2-carboxyethylthiocysteine (CYSx) and the derivative is separated from the other amino acids. Citrulline which is present in some matrices and it is separated from other amino acids is not included in the method performance evaluation in the single laboratory validation (SLV). Method The proposed method met all the performance requirement limits set in standard method performance requirements (SMPR) 2014.013 for total proteinogenic amino acids and taurine. The correlation coefficient of multi-point calibration was not less than 0.999 for any amino acids at any point in the SLV study confirming the validity of linear dynanic range (LDR) and linearity of the method. The individual amino acids in the chromatogram were identified by absolute retention time and relative retention time (RRT) with respect to the internal standard norvaline. There were no significant (S/N Ratio <10) interferences from the reagents or by-products of derivatisation and targeted matrices. The method demonstrated high selectivity. Result Accuracy of the method was validated using standard reference materials (NIST SRM 1869 and 1849a) and spike recovery studies. The amino acid results in the SRMs were within the ranges of Reference Mass Fraction Values. The accuracy of the method was corroboratively validated by spike recovery studies. The average spike recovery range between 93 to 107% ensure the accuracy of the method for amino acids and compliance to the AOAC SMPR 2014.013. Conclusions Precision data of the method demonstrate that it meets the stakeholder requirements as per the SMPR. The mean RSDr for all the amino acids for 17 matrices selected for the SLV were not more than 4%. The method is very sensitive and the LOQ can go down to approximately ten times lower than the SMPR requirements. The sensitivity of method is a direct reflection of its signal to noise ratio which ensures guaranteed method performance at the lower levels of amino acids in these matrices. Highlights Taurine (aminoethane sulfonic acid) unlike the other amino acids is a beta-sulfonic amino acid that is not used in protein synthesis but is found as a free amino acid in tissues. The acidic functional group (-COOH) in common amino acid is replaced with a sulfonic acid (-SO3H) group in Taurine. The method offers baseline separation of citrulline which is an alpha amino acid generally present in Infant Formula and Adult/Pediatric Nutritional products. The separation of citrulline eliminates the risk of interference of this compound with other amino acids. The method can also separate and quantitate hydroxyproline, an important component of collagen that is often used to quantitate collagen. The method is simple and does not include any proprietary chemicals or instruments and can be performed on any basic reverse phase UHPLC system with UV detection.

Quantitative decarboxylation of [ 14 C]amino acids using automatic amino acid analyzer

1976 ◽  
Vol 72 (1-2) ◽  
pp. 305-309
Author(s):  
David E. Peterson ◽  
Nyles W. Charon ◽  
Russell C. Johnson
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Automatic Amino Acid Analyzer ◽  
Amino Acid Analyzer

Ionenaustausch-chromatographische Untersuchungen über die freien Aminosäuren und deren Derivate in Drosophila melanogaster

1965 ◽  
Vol 20 (4) ◽  
pp. 307-312 ◽  
Author(s):  
P. S. Chen ◽  
F. Hanimann
Keyword(s):  
Amino Acids ◽  
Drosophila Melanogaster ◽  
Amino Acid ◽  
Partition Chromatography ◽  
Automatic Amino Acid Analyzer ◽  
Amino Butyric Acid ◽  
Amino Acid Analyzer ◽  
Tyrosine Phosphate ◽  
Distinct Separation ◽  
Metabolic Significance

By using the automatic amino acid analyzer (model 120 B, Beckman) the free ninhydrin-positive components in the methanol extracts of Drosophila melanogaster were fractionated. Compared to the conventional paper partition chromatography the great advantage of this technique is the distinct separation of such amino acids like leucine, isoleucine, phenylalanine, valine, methionine, γ-amino-butyric acid as well as the basic components ornithine, lysine, histidine and arginine. Furthermore, the occurrence of phosphoserine, tyrosine phosphate, ethanolamine, phosphoethanolamine and glycerophosphoethanolamine was identified. The metabolic significance of these substances is discussed.

Comparative Analysis of Free Amino Acids in Parapenaeopsis hardwickii, Penaeus vannamei and Macrobrachium nipponensis

2013 ◽  
Vol 781-784 ◽  
pp. 1528-1533
Author(s):  
Yi Hua Zhang ◽  
Shun Sheng Chen ◽  
Wei Qiang Qiu ◽  
Shou Kun Cheng
Keyword(s):  
Amino Acids ◽  
Comparative Analysis ◽  
Amino Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Penaeus Vannamei ◽  
High Concentration ◽  
Automatic Amino Acid Analyzer ◽  
Low Concentration ◽  
Amino Acid Analyzer

The contents of free amino acids(FAAs) in Parapenaeopsis hardwickii, Penaeus vannamei and Macrobrachium nipponensis was analyzed by using the automatic amino acid analyzer in this study. The results show that the sequence from the highest to the lowest in total amount of FAAs is Parapenaeopsis hardwickii, Penaeus vannamei and Macrobrachium nipponensis. SPSS(19.0) results indicate that except for Cys, Lys and Thr, FAAs in these three shrimps are significant different (p<0.05), and all of them have a high concentration of Arg, Gly and Pro and a low concentration of Asp and Cys. The content of Gly in shrimp is higher than that of crab and oyster. Both Arg and Gly significantly contribute to the taste of the three shrimps, Glu and Pro play an important role in the flavor of Parapenaeopsis hardwickii and Penaeus vannamei, while not as significant as in the taste of Macrobrachium nipponensis. Composition modes of FAAs which make major contributions to flavor in marine shrimps, Parapenaeopsis hardwickii and Penaeus vannamei, are similar, but different from freshwater shrimp, Macrobrachium nipponensis.

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