Rapid amino acid analysis of beers using flow-gated capillary electrophoresis coupled with side-by-side calibration

2017 ◽  
Vol 9 (31) ◽  
pp. 4520-4526 ◽  
Author(s):  
Qingfu Zhu ◽  
Ning Zhang ◽  
Maojun Gong
Keyword(s):  
Amino Acids ◽  
Capillary Electrophoresis ◽  
Amino Acid ◽  
Amino Acid Analysis

Side-by-side calibration is enabled by alternate injections in flow-gated capillary electrophoresis to rapidly perform amino acid analysis, an important procedure to measure amino acids in various samples.

scholarly journals A Practical Approach to the Investigation of Amino Acid Disorders

1988 ◽  
Vol 25 (2) ◽  
pp. 129-141 ◽  
Author(s):  
M A Edwards ◽  
S Grant ◽  
A Green
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Analysis ◽  
Practical Approach ◽  
The Common ◽  
Common Problems

We have, in this paper, highlighted some of the common problems in amino acid analysis in our experience and listed the possible causes for increases in specific amino acids in urine—together with guidance on appropriate follow-up investigations.

Comparison of Interlaboratory Variation in Amino Acid Analysis and Rat Growth Assays for Evaluating Protein Quality

1985 ◽  
Vol 68 (1) ◽  
pp. 52-56 ◽  
Author(s):  
Ghulam Sarwar ◽  
Robert Blair ◽  
Mendel Friedman ◽  
Michael R Gumbmann ◽  
Ross L Hackler ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Analysis ◽  
Protein Quality ◽  
Essential Amino Acids ◽  
Quality Indices ◽  
Protein Ratio ◽  
Protein Sources ◽  
Rat Growth ◽  
Positive Correlations

Abstract Estimates of inter- and intralaboratory variation of protein efficiency ratio (PER), relative PER (RPER), net protein ratio (NPR), relative NPR (RNPR), and nitrogen utilization (NU) were compared with those of amino acid analysis in the same batches of 7 protein sources (ANRC casein, egg white solids, minced beef, soy assay protein, rapeseed protein concentrate, pea flour, and whole wheat flour). Interlaboratory variation (estimated as between-laboratories coefficients of variation, CV) of NPR and RNPR (up to 6.0%) was lower than that of PER (up to 20.2%) and RPER (up to 18.5%). The interlaboratory determination of NPR and RNPR was also more reproducible than that of most essential amino acids (CV up to 10.0%), especially tryptophan (CV up to 23.7%), cystine (CV up to 17.6%), and methionine (CV up to 16.1%). Intralaboratory variation (estimated as within-laboratories CV) of amino acid analysis (up to 4.7%), however, was comparable to that of protein quality indices in most protein sources (up to 6.0%). The significant (P <0.01) positive correlations (r = 0.68-0.74) between amino acid scores and protein quality indices based on rat growth were further improved when amino acid scores were corrected for digestibility of protein (r = 0.73-0.78) or individual amino acids (r = 0.79- 0.82).

scholarly journals Profiling of Amino Acids in Urine Samples of Patients Suffering from Inflammatory Bowel Disease by Capillary Electrophoresis-Mass Spectrometry

Molecules ◽  
2019 ◽  
Vol 24 (18) ◽  
pp. 3345 ◽  
Author(s):  
Juraj Piestansky ◽  
Dominika Olesova ◽  
Jaroslav Galba ◽  
Katarina Marakova ◽  
Vojtech Parrak ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Amino Acids ◽  
Inflammatory Bowel Disease ◽  
Capillary Electrophoresis ◽  
Amino Acid ◽  
Bowel Disease ◽  
Urine Samples ◽  
Simultaneous Action ◽  
Relative Standard ◽  
Inflammatory Bowel

Urine represents a convenient biofluid for metabolomic studies due to its noninvasive collection and richness in metabolites. Here, amino acids are valuable biomarkers for their ability to reflect imbalances of different biochemical pathways. An impact of amino acids on pathology, prognosis and therapy of various diseases, including inflammatory bowel disease (IBD), is therefore the subject of current clinical research. This work is aimed to develop a capillary electrophoresis-tandem mass spectrometry (CE-MS/MS) method for the quantification of the 20 proteinogenic amino acids in human urine samples obtained from patients suffering from IBD and treated with thiopurines. The optimized CE-MS/MS method, with minimum sample preparation (just “dilute and shoot”), exhibited excellent linearity for all the analytes (coefficients of determination were higher than 0.99), with inter-day and intra-day precision yielding relative standard deviations in the range of 0.91–15.12% and with accuracy yielding relative errors in the range of 85.47–112.46%. Total analysis time, an important parameter for the sample throughput demanded in routine practice, was shorter in ca. 17% when compared to established CE-MS methods. Favorable performance of the proposed CE-MS/MS method was also confirmed by the comparison with corresponding ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS) method. Consistent data for the investigated amino acid metabolome were obtained using both methods. For the first time, the amino acid profiling by CE-MS approach was applied on the clinical IBD samples. Here, significant differences observed in the concentration levels of some amino acids between IBD patients undergoing thiopurine treatment and healthy volunteers could result from the simultaneous action of the disease and the corresponding therapy. These findings indicate that amino acids analysis could be a valuable tool for the study of mechanism of the IBD treatment by thiopurines.

Recent advances in amino acid analysis by capillary electrophoresis

2003 ◽  
Vol 24 (2223) ◽  
pp. 4047-4062 ◽  
Author(s):  
Véréna Poinsot ◽  
Christophe Bayle ◽  
François Couderc
Keyword(s):  
Capillary Electrophoresis ◽  
Amino Acid ◽  
Amino Acid Analysis ◽  
Recent Advances

scholarly journals Separation of two forms of rabbit metallothionein by isoelectric focusing

1972 ◽  
Vol 126 (3) ◽  
pp. 491-498 ◽  
Author(s):  
G F Nordberg ◽  
M. Nordberg ◽  
M. Piscator ◽  
O. Vesterberg
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Isoelectric Focusing ◽  
Amino Acid Analysis ◽  
Cadmium Chloride ◽  
Small Difference ◽  
Isoelectric Points ◽  
Main Protein ◽  
Similar Content ◽  
The One

Rabbits were given repeated injections of cadmium chloride. Cadmium- and zinc-containing protein fractions were obtained from the livers of these animals by precipitation procedures and Sephadex G-75 chromatography. The protein thus obtained showed several characteristics similar to those of the earlier described protein metallothionein. Further separation by isoelectric focusing showed two main protein peaks with isoelectric points at 3.9 and 4.5 respectively. Amino acid analysis of these two forms showed similar content of most amino acids [residues per cent.: cysteine (28%), aspartate (8%), threonine (5–6%), serine (12%), glycine (7%), alanine (13%), methionine (2%), isoleucine (2%)] but with a small difference in content of lysine (12 and 13% respectively), proline (9 and 5% respectively) and glutamate (2 and 4% respectively). The two forms of the protein both contained cadmium, but only the one with pI4.5 contained also significant amounts of zinc.

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