Application of alrestatin chloride as a derivatizing reagent for the determination of amino acids, catecholamines and biogenic amines in urine

• A novel derivatization reagent – alrestatin chloride was investigated. • A comparison study with commonly used FMOC Cl and dansyl chloride was shown. • Method validation study was shown. • Method optimization was shown. The feasibility of using alrestatin chloride as a derivatization reagent was evaluated. Selected amino acids, catecholamines, and biogenic amines were tested. Limits of detection (LOD), limits of quantification (LOQ), and key analytical performance parameters were determined. Depending on the analyte, the detection limit varied from 0.1 to 5 ng/ml, and the error did not exceed 15 %, which allows the effective use of alrestatin chloride as a derivatizing reagent and significantly exceeds FMOC Cl and dansyl chloride in sensitivity. An important advantage established for these derivatives is that they are stable over a long period of time. A proposed interpretation of the amino acid derivative is presented, and optimal MRM transitions for quantitative and qualitative analysis are established. It is shown that, although the proposed derivatization approach provides high sensitivity, prolonged heating is required to ensure a complete derivatization reaction, which can negatively impact analyte stability.