OBJECTIVE: To establish the method for concentration determination of isoniazid

rifampicin

pyrazinamide and ethambutol in human cerebrospinal fluid by high performance liquid chromatography-mass spectrometry/mass spectrometry（ HPLC-MS/MS）

to achieve the accurate determination of anti-tuberculosis drugs in cerebrospinal fluid of patients with tuberculous meningitis

so as to provide evidence for clinical medication guidance.METHODS: The supernatant uid was separated on the Agilent Poroshell 120 SB C18 column（ 4. 6 mm × 50 mm

2. 7 μm）

methanol-0. 2% acetic acid solution was mobile phase（ gradient elution）. Electrospray ionization source was applied and operated in the positive multiple reaction monitoring（ MRM） mode. Acetaminophen was used as internal standard. The proteins of cerebrospinal fluid was precipitated with methanol. The transition of m/z was138. 0→121. 0 for isoniazid

823. 2 → 791. 2 for rifampicin

124. 1 → 79. 0 for pyrazinamide

205. 2 → 116. 1 for ethambutol

and 152. 0 → 110. 0 for acetaminophen. Each analysis was completed within 12 minutes. RESULTS:Endogenous substances in cerebrospinal fluid had no interference with the determination

and the matrix effect was small. The linear ranges of isoniazid

rifampicin

pyrazinamide and ethambutol were 0. 196-9. 8

0. 6-30. 0

1. 0-50. 0 and 0. 16-8. 0 μg/ml

respectively

and the linear relationships were good. The intra-day and inter-day precision RSD of this method for each drug were < 10%

and the extraction recovery rate was relatively high. CONCLUSIONS: The method is stable

specific and accurate

and proved to be suitable for the concentration determination of isoniazid

rifampicin

pyrazinamide and ethambutol in human cerebrospinal fluid from clinical samples.