TITLE:
Methodological Optimization and Clinical Application Value Analysis of LC-MS/MS for Monitoring Antipsychotic Blood Concentrations
AUTHORS:
Peng Huang, Guosheng Su, Liwen Huang, Liefu Long, Ruijian Lu, Jieling Lu, Tiaoping Tao
KEYWORDS:
Liquid Chromatography-Tandem Mass Spectrometry, Antipsychotics, Therapeutic Drug Monitoring, Methodological Optimization, Clinical Application
JOURNAL NAME:
International Journal of Analytical Mass Spectrometry and Chromatography,
Vol.14 No.1,
March
31,
2026
ABSTRACT: Objective: To address the problems of cumbersome pretreatment, low detection efficiency and insufficient coverage of some drugs in clinical monitoring of antipsychotic blood concentrations, a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was systematically optimized. Its analytical performance was validated, and its application value in personalized treatment of psychiatric disorders was explored, aiming to provide a standardized technical solution for therapeutic drug monitoring (TDM) in primary healthcare institutions. Methods: Five commonly used clinical antipsychotics—haloperidol, amisulpride, olanzapine, clozapine, and perphenazine—were selected as target analytes. The sample pretreatment process (precipitant ratio, centrifugation conditions, and injection volume) was optimized, along with the chromatographic gradient elution program and mass spectrometry ion source parameters, to establish an optimized LC-MS/MS method. Comprehensive validation was performed according to the guiding principles of Section 9012, Part IV of the 2020 Chinese Pharmacopoeia, assessing selectivity, linearity, precision, accuracy, matrix effect, and stability. For samples exceeding the validated linear range (10 - 250 ng·mL−1), serial dilution (2- to 5-fold) with blank serum was performed before reanalysis, and the final concentration was calculated by multiplying the detected value by the corresponding dilution factor A total of 100 patients with schizophrenia prospectively enrolled in The Second People’s Hospital of Baise from January to December 2025 were included, who received monotherapy with haloperidol, amisulpride, olanzapine, clozapine, or perphenazine (20 patients per group). All patients were excluded from smoking history, hepatic or renal impairment, and concomitant use of CYP450 enzyme modulators. Medication adherence was verified by outpatient follow-up, medication records and the trend of blood drug concentrations. The optimized method was used to determine the steady-state trough serum concentrations in the morning before medication after 4 weeks of treatment. According to the AGNP 2011 guidelines and the serum matrix-adapted quantitative therapeutic windows (haloperidol 50 - 150 ng·mL−1, amisulpride 80 - 200 ng·mL−1, olanzapine 20 - 80 ng·mL−1, clozapine 350 - 600 ng·mL−1, perphenazine 4 - 12 ng·mL−1), patients were stratified into three groups: within the therapeutic window, below the window, and above the window. The Positive and Negative Syndrome Scale (PANSS) was used to evaluate clinical efficacy at baseline (before treatment) and 4 weeks after treatment. The correlation between blood concentrations and clinical efficacy/adverse reactions was analyzed, and the concentration-effect relationship was further stratified by drug type. Results: The optimized method employed an acetonitrile-methanol (9:1, v/v) mixture for protein precipitation, centrifugation at 14,500 rpm for 6 min, and an injection volume of 3 μL, with the total analysis time shortened to 6 min. Each drug exhibited good linearity in the range of 10 - 250 ng·mL−1 with correlation coefficients (r2) all ≥ 0.9990. The lower limit of quantification (LLOQ) was 10 ng·mL−1 with a signal-to-noise ratio (S/N) ≥ 16. Intra-day and inter-day precisions (relative standard deviation, RSD) were ≤7.5% and ≤9.2%, respectively, and accuracy ranged from 95.1% to 105.8%. The matrix effect ranged from 86.2% to 112.5%. Samples showed good stability under various storage conditions with concentration changes of ≤±10%. There were no significant differences in baseline characteristics (age, gender, disease course, baseline PANSS score) and daily drug dose among the three groups (P > 0.05), indicating good comparability. Among the 100 patients, 65 (65.0%) had concentrations within the therapeutic window, 22 (22.0%) were below, and 13 (13.0%) were above. In the within-window group, the clinical total effective rate was 92.3% and the incidence of adverse reactions was 18.5%. In the below-window group, the effective rate was 50.0% with no significant adverse reactions. In the above-window group, the effective rate was 76.9% but the adverse reaction rate was 69.2%, with statistically significant differences among the three groups (P Conclusion: The optimized LC-MS/MS method is simpler, faster and has superior analytical performance, enabling rapid quantitative determination of multiple antipsychotics in serum with a reliable dilution method for over-range samples. This method can accurately reflect the correlation between serum concentrations of the five antipsychotics and clinical efficacy/adverse reactions with a consistent concentration-effect trend across different drugs, providing reliable experimental evidence for clinicians to adjust dosages and implement personalized treatment. It is suitable for promotion and application in primary mental health institutions.