Fudan University Journal of Medical Sciences

Establishment of a LC-MS/MS method for detecting gamma-aminobutyric acid in plasma and its clinical application

Jia-qian QIN, Lei CAO, Ying-fei PENG, Fang-jun CHEN, Bai-shen PAN, Bei-li WANG, Wei GUO

Fudan University Journal of Medical Sciences, 2025, 52(05): 708-716. DOI: 10.3969/j.issn.1672-8467.2025.05.012

Analyte	Ion mode	Precursor-product ion pair（m/z）	Cone voltage（kV）	Collision energy（eV）
Quantitative GABA	ESI+	104.1→87.15	15	9
Qualitative GABA	ESI+	104.1→69.15	15	13
GABA IS	ESI+	110.1→93.20	15	10
AABA	ESI+	104.1→58.00	20	8

Tab 2 Detection parameters of mass spectrometry

Other figure/table from this article

Fig 1 Isomers of GABA
Tab 1 Gradient of mobile phase
Fig 2 Effect of different mobile phase ratios on GABA response Chromatograms obtained with different mobile phase compositions. A: Mobile phase A1 (0.05% formic acid in water) and mobile phase B1 (90% acetonitrile in water) containing 5 mmol/L ammonium acetate; B: Mobile phase A1 (0.05% formic acid in water) and mobile phase B1 (90% acetonitrile in water) containing 0.10% formic acid and 5 mmol/L ammonium acetate; C: Mobile phase A1 (0.05% formic acid in water) and mobile phase B1 (90% acetonitrile in water) containing 0.175% formic acid and 5 mmol/L ammonium acetate.
Fig 3 Chromatogram of GABA and its internal standard A: GABA standard; B: GABA-d6. RT: Retention time.
Fig 4 Chromatogram of GABA in clinical samples A: GABA sample (0.1 μmol/L); B: GABA-d6. RT: Retention time.
Fig 5 Chromatogram of AABA standard A: AABA standard; B: GABA channel. RT: Retention time.
Fig 6 Chromatogram of GABA and AABA in clinical samples A: AABA sample; B: GABA channel. RT: Retention time.
Tab 3 Performance validation results
Tab 4 ROC analysis of GABA for the auxiliary diagnosis of patients with sleep disorders stratified by age