Ukr.Biochem.J. 2016; Volume 88, Issue 5, Sep-Oct, pp. 107-115


Measurement of methionine level with the LC-ESI-MS/MS method in schizophrenic patients

S. Kulaksizoglu1, B. Kulaksizoglu2, H. Y. Ellidag1, E. Eren1, N. Yilmaz1, A. Baykal3

1Central Laboratories of Antalya Education and Research Hospital,
Department of Biochemistry, Antalya, Turkey;
2Antalya Education and Research Hospital, Department of Psychiatry, Antalya, Turkey;
3Akdeniz University School of Medicine, Department of Biochemistry, Antalya, Turkey

The purpose of this study was to evaluate plasma methionine levels by using liquid chromatography electrospray ionization-tandem mass spectroscopy (LC-ESI-MS/MS) in schizophrenic patients. A twelve-point standard graph was drawn, and the recovery rate, the intra-day and inter-day coefficients of variation (CV), the limit of detection (LOD), and the limit of quantification (LOQ) were evaluated. The y and R2 values of the standard graph equation were determined as 0.011x + 0.0179 and 0.9989, respectively, and the graph remained linear until the 200 µmol/l level. The intra-day coefficients of variation of the samples (n = 10) containing 8, 28, and 58 µmol/l methionine were determined as 2.68, 3.10, and 3.79%, respectively; while their inter-day coefficients of variation were determined as 2.98, 3.19, and 3.84%. The LOD and LOQ values were determined as 0.04 and 0.1 µmol/l, respectively, while the mean recovery rates were determined as 101.7 and 99.3%. Plasma methionine values were measured as 21.5 (19.5-24,6) µmol/l for the patient group, 17.8 (16.3-20.1) µmol/l for the control group, and the difference between the two groups was statistically significant (p = 0.03). LC-ESI-MS/MS method represents a fairly sensitive, economic, and rapid analysis that requires very little sample and is suitable for measuring methionine levels in schizophrenic patients.

Keywords: , , , ,


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