ABSTRACT The effectiveness of L‐asparaginase and therefore the effectiveness of acute lymphoblastic leukemia treatment will be understood by determining the substrates of the enzyme, L‐asparagine and L‐glutamine. For this purpose, the high‐performance liquid chromatography–tandem mass spectrometry method was developed and validated by analyzing the L‐asparaginase substrates asparagine and glutamine and its products aspartic acid and glutamic acid from plasma. Acetonitrile and ammonium acetate were used at 0.4 mL/min in gradient mobile phase flow using a HILIC column for chromatographic separations. The linear amino acid range was found to be 500–5000 ng/mL for asparagine, aspartic acid, and glutamic acid, and 5–50 μg/mL for glutamine, respectively. Detection limit and quantitation limit were found to be 100–500 ng/mL for asparagine, aspartic acid, and glutamic acid, and 1–5 μg/mL for glutamine, respectively. The validated method has been successfully applied to plasma samples. The method was found to be selective and reproducible.
Kaplan et al. (2026) studied this question.