The Determination of Polymyxin B in Critically Ill Patients by the HPLC-MS/MS Method

Table 1

Extraction recovery and matrix effect of PB.

Component	Extraction recovery			Matrix effect
	Nominal concentration (ng/mL)	Recovery		QC level	Mean of normalized MF	CV (%)
		Mean (%)	CV (%)
PB1/PB1-I	200	91.9	4.3	QCL	1.03	12.7
	1000	97.0	1.1
	4000	94.3	2.7	QCH	1.10	6.4
	7000	92.1	1.9
PB2/PB3	23.7	98.4	3.6	QCL	1.03	8.9
	118.6	99.1	0.7
	474.3	97.6	0.9	QCH	1.05	5.3
	830.0	95.8	2.2