Amino acid measurement by high-performance liquid chromatography using electrochemical detection

Sherwood, Roy

doi:10.1016/0165-0270(90)90037-g

Cited by 16 publications

(6 citation statements)

References 14 publications

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“…Underivatised amino acids can also be detected electrochemically [ 34 , 35 , 36 ]. Nevertheless, amino acids are often derivatised to improve sensitivity or enhance separation on reverse phase columns [ 37 , 38 ]. Although electrochemical detection of amino acids offers high sensitivity this technique is comparatively little applied since the use of electrochemical detectors is not very widespread.…”

Section: Introductionmentioning

confidence: 99%

Quantification of Glutamate and Aspartate by Ultra-High Performance Liquid Chromatography

et al. 2018

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Glutamic and aspartic acid fulfil numerous functions in organisms. They are proteinogenic amino acids, they function as neurotransmitters, and glutamic acid links the citrate cycle with amino acid metabolism. In addition, glutamic acid is a precursor for many bioactive molecules like γ-aminobutyric acid (GABA). In tomatoes, glutamic acid accumulates in ripening fruits. Here we present a simple and rapid method for quantification of glutamate and aspartate in tomatoes. A cleared extract is prepared and 2-aminoadipic acid added as internal standard. Subsequently, the amino acids are derivatised with 2,4-dinitro-1-fluorobenzene under alkaline conditions. The derivatives are separated by ultra-high performance liquid chromatography using a phenyl-hexyl column and 50 mM N-methylmorpholine/acetate buffer pH 7.4 containing 12% acetonitrile as eluent and detected by UV absorption at 363 nm. The whole analysis time including separation and column equilibration takes less than 2.8 min with a flow rate of 1 mL/min and less than 1.6 min with a flow rate of 2 mL/min, making this method suitable for high-throughput applications. The method shows excellent reproducibility with intra- and inter-day SDs of approximately 4% for both aspartic and glutamic acid. Using this method we show that the glutamate/aspartate ratio changes significantly during fruit ripening.

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Section: Introductionmentioning

confidence: 99%

Quantification of Glutamate and Aspartate by Ultra-High Performance Liquid Chromatography

et al. 2018

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“…The chromatographic separation was done by gradient elution of the amino acids, stage also described by Sherwood, 1990. This stage is accompanied by a stage of derivatization which can be done either before (pre-column), or after (postcolumn) separation (Peace et al, 2005).…”

Section: Resultsmentioning

confidence: 99%

Evaluation of the dietary protein using an optimized HPLC method

et al. 2011

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Protein quality is determined by the type and concentration of the essential amino acids and by their bioavailability. Hence, the content of dietary essential amino acids from a protein or mixture of proteins is a factor which determines the feeding quality of the protein. The purpose of the study was to evaluate the quality of the protein from a high protein raw ingredient (corn gluten) using a chromatographic method (HPLC) under optimized experimental conditions. In this study, we used pre-column derivatization, separation by high-performance liquid chromatography (HPLC) and UV detection. The optimized method was used to determine the amino acids from high-protein raw ingredients commonly used in animal feeding (corn gluten, 61%CP). A set of 6 amino acids analyses has been performed in 6 different days, each sample being prepared in double. For characterization of data strings we used quality parameters: average, standard deviation, standard error, confidence level, precision, accuracy. For verifying the Gaussian shape of the strings we used the Kernel Density. For identifying and rejecting the outliers from the data strings we used the Q test. The very low values of the accuracy for several amino acids (glutamic acid, threonine, alanine, valine, phenylalanine, isoleucine, leucine) determined us to introduce the dilution stage (1:2) for the hydrolysed samples. The method can be considered as repeatable (precision in different days) and accurate (evaluation by tracing yields) for all the determined amino acids.

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“…An extra blood sample was taken in a heparinised tube and spun at 2000 g for 10 min. The plasma was then stored at À701C before analysis of amino acids by high-performance liquid chromatography (Sherwood, 1990).…”

Section: Additional Variables/measurementsmentioning

confidence: 99%

A double-blind, randomized, controlled crossover trial of glutamine supplementation in home parenteral nutrition

et al. 2007

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Objective: Studies suggest clinical benefit of glutamine-supplemented parenteral nutrition. The aim was to determine if the inclusion of 10 g of glutamine as part of the nitrogen source of home parenteral nutrition (HPN) reduces infectious complications. Subjects/Methods: Thirty-five patients on HPN were recruited and 22 completed the study. Patients were randomized to receive either standard HPN or glutamine-supplemented HPN. Patients were assessed at randomization, 3 and 6 months later then they were crossed over to the alternative HPN and reassessed at 3 and 6 months. Assessments included plasma amino acid concentrations, intestinal permeability and absorption, nutritional status, oral and parenteral intake, quality of life, routine biochemistry and haematology. Results: No difference was seen between the groups at randomization. No difference was detected between the treatment phases for infective complications (55% in the standard treatment phase and 36% in the glutamine-supplemented phase P ¼ 0.67). There were no differences in nutritional status, intestinal permeability, plasma glutamine concentrations or quality of life. Conclusion: Although limited by the sample size, the study has shown that glutamine as part of the nitrogen source of parenteral nutrition can be given to patients on HPN for 6 months without any adverse effects.

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Amino acid measurement by high-performance liquid chromatography using electrochemical detection

Cited by 16 publications

References 14 publications

Quantification of Glutamate and Aspartate by Ultra-High Performance Liquid Chromatography

Quantification of Glutamate and Aspartate by Ultra-High Performance Liquid Chromatography

Evaluation of the dietary protein using an optimized HPLC method

A double-blind, randomized, controlled crossover trial of glutamine supplementation in home parenteral nutrition

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