Determination of free tyrosine in equestrian supplements by LC–MS/MS and comparison of its quantity with total free amino acids content in view of doping control

Waraksa, Emilia; Kowalski, Konrad; Rola, Rafał; Kłodzińska, Ewa; Bieńkowski, Tomasz; Namieśnik, Jacek

doi:10.1016/j.microc.2018.12.033

Cited by 9 publications

(4 citation statements)

References 32 publications

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“…However, ninhydrin is still frequently used as a derivatisation reagent for spectrophotometric or chromatographic determination of amino acids [7,13,30]. Moreover, when it came to measure total content of free amino acids, the ninhydrin spectrophotometric method is still adopted [31]. The main advantages of the procedure with ninhydrin are: reactivity, reaction rate, simplicity of derivatisation with a pre-, and post-column procedure.…”

Section: Analytical Parameters Of Ninhydrin Proceduresmentioning

confidence: 99%

“…Different ninhydrin reaction conditions, including organic solvents, temperature, heating time, the buffer used (phosphate, sodium acetate, lithium acetate, potassium acetate, sodium citrate, etc.) were described in the literature [14,31]. We proposed a derivatisation procedure based on the application of acetate buffer and heating for 30 min.…”

Section: Analytical Parameters Of Ninhydrin Proceduresmentioning

confidence: 99%

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Simple extraction procedure for free amino acids determination in selected gluten-free flour samples

Kowalska

Szłyk

Jastrzębska

2021

Eur Food Res Technol

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The simple extraction of flours samples followed by free amino acids determination procedures was studied and optimised. The conditions of amino acids derivatisation reaction with ninhydrin for chromatographic determination of free amino acids sum was discussed. The developed method was processed in terms of linearity, precision, accuracy, and limits of detection and quantification. Moreover, capillary isotachophoresis and HPLC methods were applied for individual free amino acids determination. The proposed extraction procedure is simple, fast and convenient for different flours samples. Studied procedures were used for free amino acids determination in twelve gluten-free flour samples (corn, oat, soy, rice, pumpkin, millet, peanut, hemp seed, buckwheat, amaranth, pea and chickpea) and the obtained results were compared with wheat flour.

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Section: Analytical Parameters Of Ninhydrin Proceduresmentioning

confidence: 99%

Section: Analytical Parameters Of Ninhydrin Proceduresmentioning

confidence: 99%

Simple extraction procedure for free amino acids determination in selected gluten-free flour samples

Kowalska

Szłyk

Jastrzębska

2021

Eur Food Res Technol

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“…On the other hand, the reduction of Tyr can reduce the protein synthesis. [3] Altough several analytical methods by spectrometric and chromatographic techniques have been reported for Tyr determination, [4][5][6][7] they are expensive, time-consuming and require complicated sample pre-treatment. For this purpose, electrochemical sensors can be an important tool for Tyr determination due to their attractive properties, such as high sensitivity, cost-effectiveness reliable, quick response, simple sample preparation, and enable in-situ analysis.…”

Section: Introductionmentioning

confidence: 99%

Infrared Laser‐Induced Graphene Sensor for Tyrosine Detection

et al. 2022

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In this work, we demonstrate that laser‐induced graphene (LIG) electrodes produced by a single‐step infrared irradiation on a commercially available polyimide sheet work as portable platforms for the electrochemical detection of tyrosine (Tyr). The LIG surface was characterized by Raman and scanning electron microscopy, which confirmed the formation of graphene with a highly porous structure. The sensor associated with differential‐pulse voltammetry provided the determination of Tyr with a linear range between 5 and 30 μmol L−1, a limit of detection (LOD) of 1.5 μmol L−1, precision of 6.2 % (n=10), and a satisfying selectivity towards interfering species found in biological media (e. g., dopamine, urea, and both ascorbic and uric acids). Artificial urine samples spiked with different amounts were analyzed by the proposed sensor and recovery values between 107 and 114 % were obtained. Opposite to many works reported in the literature, this platform did not require costly and time‐consuming surface modification processes, being an alternative feasible for other applications of clinical/medical interest. One LIG electrode sensor is produced in 140 s without chemical waste generation.

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“…There are several reported methods for the determination of amino acids including, chromatographic methods [9], gas chromatography-mass spectrometry [10], chemiluminescence [11], capillary electrophoresis [12], LC-MS/MS [13]and electrochemical methods [14][15][16][17]. Among these, electrochemical techniques have attracted considerable attention for the determination of amino acids due to its high sensitivity, precision, ease of operation, low costs and short analysis times.…”

Section: Introductionmentioning

confidence: 99%

Application of carboxylic acid-functionalized of graphene oxide for electrochemical simultaneous determination of tryptophan and tyrosine in milk

Fooladi¹,

Razavizadeh²,

Noori³

et al. 2020

SN Appl. Sci.

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In this work, a new method for the simultaneous determination of tryptophan (Trp) and tyrosine (Tyr) in milk has been reported. Trp and Tyr are essential amino acids in human nutrition, but their electrochemical signal overlapped. For solve this problem, we developed modified Screen Printed Carbon Electrode (SPCE) with Graphene Oxide-COOH/Chitosan (GO-COOH/Chitosan) electro-deposition. The morphology and electrochemical performance of modified electrode were characterized by scanning electron microscopy, energy dispersive spectrometry, FT-IR, electrochemical impedance spectroscopy and cyclic voltammetry. The electrochemical simultaneous determination of Trp and Tyr has been investigated by using differential pulse voltammetry. The carboxylic acid functionalized GO modified SPCE was utilized to catalyze the oxidation of Trp and Tyr. Compared with SPCE/GO/Chitosan and SPCE/Chitosan sensor, the new sensor has enhanced sensitivity, low detection limit and high selectivity. In addition, the SPCE/GO-COOH-Chitosan sensor enhanced separation of the oxidation peak of Tyr and Trp and showed a remarkable increase in peak current for electroactive compounds, thus, it can be used for simultaneous voltammetric determination. Under the optimized experimental conditions, a linear correlation between oxidation peak current and concentration of Tyr and Trp in the ranges 0.1-60 µM and 0.4-40 µM with a detection limit of 0.05 µM (S/N = 3) and 0.1 µM (S/N = 3) were achieved, respectively. Finally, the proposed electrochemical sensor was applied for quantification of Tyr and Trp in milk samples, where standard solutions were spiked to the milk samples and recoveries were obtained.

show abstract

Determination of free tyrosine in equestrian supplements by LC–MS/MS and comparison of its quantity with total free amino acids content in view of doping control

Cited by 9 publications

References 32 publications

Simple extraction procedure for free amino acids determination in selected gluten-free flour samples

Simple extraction procedure for free amino acids determination in selected gluten-free flour samples

Infrared Laser‐Induced Graphene Sensor for Tyrosine Detection

Application of carboxylic acid-functionalized of graphene oxide for electrochemical simultaneous determination of tryptophan and tyrosine in milk

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