Tryptophan determination in milk-based ingredients and dried sport supplements by liquid chromatography with fluorescence detection

No effect of oral l-tryptophan or alpha-lactalbumin on total tryptophan levels in breast milk

“…Free tryptophan in plasma and breast milk samples Free tryptophan was separated and quantified by high pressure liquid chromatography with fluorescence detection (HPLC-FLD) adapted from the Iizuka et al (2011), Carratù et al (2003, Delgado-Andrade et al (2006) methods. Unlike the analysis of other amino acids, derivatization with a fluorophore prior to the analysis was not needed, since those two compounds exhibit native fluorescence.…”

Carbon Paste Electrode Incorporating 1‐[4‐(Ferrocenyl Ethynyl) Phenyl]‐1‐Ethanone for Electrocatalytic and Voltammetric Determination of Tryptophan

“…The electroanalytical methods, with respect to their sensitivity, accuracy, less expensive and simplicity have been more intentioned in recent years for Trp determination [3 -7]. It is well known that the direct electrochemical oxidation of Trp at the surface of a bare electrode is irreversible and therefore require high overpotential [8]. Therefore, the electrochemical detection of Trp has been shown to be facilitated by electrode chemically modification.…”

Application of a New Iridium Complex as a Chemiluminescence Reagent for the Determination of Tryptophan

“…In particular, tryptophan can be used as a starting material in the chemical synthesis of a range of drugs, because it is the precursor of the neurotransmitter serotonin. 1 Therefore, the sensitive determination of tryptophan in biological matrices and pharmaceutical samples is highly desirable. Different analytical procedures have been developed for the determination tryptophan by electrochemistry 2 and fluorescence spectroscopy 3 methods as well as chromatography.…”