Phthalylglycyl chloride as a derivatization reagent for determination of urinary amino acids using ultra high-performance liquid chromatography coupled with high resolution mass spectrometry

Abstract

A new derivatization reagent, phthalylglycyl chloride (PG-Cl), for the analysis of urinary amino acids was demonstrated using reversed-phase ultra-high performance liquid chromatography coupled to electrospray ionization-quadrupole-time-of-flight mass spectrometer. The study compares the limits of detection and quantification for different sample preparation techniques with the commonly used and effective method of derivatization using dansyl chloride. The stability of the derivatives was investigated, and the study includes an example of urinary amino acid analysis using PG-Cl derivatization. The optimal values for pH, temperature, and concentration of the derivatization reagent were established. Limits of quantification in the range of 0.5–500 µg/mL were obtained for different amino acids. The possibility of phthalylglycyl chloride usage for non-target screening applications and targeted analysis of amino acids in urine was discussed. An advantages and issues of PG-Cl in comparison with commonly used acyl-chlorides (FMOC-Cl and DNS-Cl) provided and discussed.