New quantification method for monitoring 18 l‐amino acids levels in schizophrenic patients by high‐performance liquid chromatography coupled to tandem quadrupole mass spectrometer

Abstract

A fast, uncomplicated, sensitive and fully validated high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method has been developed for estimating L-amino acids in the plasma of schizophrenic patients. The gradient-elution chromatographic method was implemented with the Luna ® PFP column (50 Â 2.0 mm, 5 μm), and a mobile phase of 0.1% formic acid in water and methanol was used. The intra-and interday variability of the L-amino acids was <13.11%, their accuracy ranged from 85.14 to 116.75% at the quality control levels and the lower limit of quantification ranged from 2.5 to 15 nM. The extraction efficiency (apparent recovery) of amino acids from healthy plasma was employed by spiking the plasma with standard amino acids at the quality control levels. Their percentage recoveries ranged from 80.4 to 119.94%. Our method has a short run time and fast sample preparation compared with existing methods, which suffer from long preparative steps and/or time-consuming analysis, restricted reagents and the suboptimal performance characteristics of presently available technologies. Therefore, the proposed HPLC-MS/MS method was effectively applied for monitoring the L-amino acids in the plasma of schizophrenic patients and healthy volunteers.

Overview of chromatographic and electrophoretic methods for the determination of branched‐chain amino acids

“…Other strategies to improve the retention of AAs in RPLC, alongside embedding polar groups, include using pentafluorophenyl (PFP) as an alternative stationary phase to replace traditional C18 and C8 stationary phases [22,118]. Kaddah et al [118] used PFP columns to separate 20 AAs, including Leu and Ile. Compared to C18 columns, this column exhibits significant advantages for isomer separation.…”

“…Kaddah et al. [118] used PFP columns to separate 20 AAs, including Leu and Ile. Compared to C18 columns, this column exhibits significant advantages for isomer separation.…”

Quantification of 16 cephalosporins in the aquatic environment by liquid chromatography‐tandem mass spectrometry

“…On the other hand, isotopically labeled ISs are not easily available because they are expensive and not commercially accessible for many drugs. In many cases, using structurally similar compounds to the analytes as an IS may be required [53][54][55]. This research paper examined different acetylated amino acids such as acetylglycine, acetylcysteine, and acetylmethionine as ISs.…”