Research Article

Development and Application of a LC-MS/MS Method for Simultaneous Quantification of Four First-Line Antituberculosis Drugs in Human Serum

Table 3

Precision and accuracy of the method at four concentration levels.

AnalytesQC levelsReferred value (μg/mL)RSD (%)Accuracy (%)
Intrarun (n = 6)Interrun (n = 6×3)Intrarun (n = 6)Interrun (n = 6×3)

PZALLOQ1.028.068.3398.43100.00
Low1.604.213.7194.9295.32
Medium16.04.593.4698.3898.46
High48.02.683.6499.63100.66

INHLLOQ0.1524.696.7095.0298.68
Low0.2682.984.6291.1394.67
Medium2.684.204.0597.6399.58
High8.042.533.9299.63100.81

EMBLLOQ0.09985.135.3997.80100.20
Low0.1612.743.9391.6794.00
Medium1.6112.468.49103.8299.58
High4.603.793.17104.62104.02

RFPLLOQ0.5005.007.2790.1598.00
Low0.8104.265.8794.0399.26
Medium8.1008.736.4395.7097.77
High24.3003.423.3996.2395.13

PZA: pyrazinamide, INH: isoniazid, RFP: rifampicin, EMB: ethambutol, QC: quality control, RSD: relative standard derivation, and LLOQ: lower limit of qualification.