Underivatized Amino Acid Chromatographic Separation: Optimized Conditions for HPLC-UV Simultaneous Quantification of Isoleucine, Leucine, Lysine, Threonine, Histidine, Valine, Methionine, Phenylalanine, Tryptophan, and Tyrosine in Dietary Supplements.

Content Provider	Europe PMC
Author	Eid, Sherif M. Farag, Mohamed A. Bawazeer, Sami
Copyright Year	2022
Abstract	Amino acids (AAs) are considered as the building blocksof life.Unlike nonessential AAs, the human body cannot synthesize essentialAAs and should be supplied in food or dietary supplements. The aimof the work is simultaneous HPLC-UV determination of 10 structurallyrelated AAs without pre- or postderivatization in powdered dietarysupplements (PDSs). This was challenging, especially because PDS hasno standardized procedures for its quality control. HPLC-UV chromatogramsof the 10 AAs were recorded using a gradient elution of the mobilephase on a CLC-C18 column at 225 nm. The elution started with 100%of phosphate buffer (pH 7.4, 10 mM) for 10 min; then, the concentrationof acetonitrile increased linearly to reach 50% for another 15 minat room temperature. Good separation was achieved within a 25 minrun time without pre- or postderivatization. The method was carefullyvalidated according to the ICH guidelines over the linearity rangeof 100–200, 50–200, 20–150, 50–400, 20–250,75–175, 50–250, 50–250, 50–300, and 5–100μg/mL for l-lysine, l-threonine, l-histidine, l-valine, l-methionine, l-isoleucine, l-leucine, l-tyrosine, l-phenylalanine, and l-tryptophan, respectively, with mean recoveries ranges between98.91 and 100.77. The method was found to be precise, and the relativestandard deviation (RSD) was found to be between 0.28 and 1.92 withrecoveries between 97.91 and 101.11. The method was found to be robustthat resists deliberate changes in pH, flow rate, and mobile-phasepercentages. It was successfully applied for the analysis of PDSs.The proposed method could be very useful for the quality control ofthe 10 structurally related AAs during their synthesis and for testingraw materials and pharmaceutical preparations.
Journal	ACS Omega
Volume Number	7
PubMed Central reference number	PMC9453785
Issue Number	35
PubMed reference number	36092579
e-ISSN	24701343
DOI	10.1021/acsomega.2c03228
Language	English
Publisher	American Chemical Society
Publisher Date	2022-08-11
Access Restriction	Open
Rights License	Permits non-commercial access and re-use, provided that author attribution and integrity are maintained; but does not permit creation of adaptations or other derivative works (https://creativecommons.org/licenses/by-nc-nd/4.0/). © 2022 The Authors. Published by American Chemical Society
Content Type	Text
Resource Type	Article
Subject	Chemistry Chemical Engineering