The Determination of Polymyxin B in Critically Ill Patients by the HPLC-MS/MS Method
Table 3
Intrabatch and interbatch precision and accuracy for PB in plasma.
Component
Nominal conc. (ng/mL)
Intraday (n = 5)
Interbatch (n = 3)
Found conc. (ng/mL) mean (SD)
Acc. (%)
CV (%)
Found conc. (ng/mL) mean (SD)
Acc. (%)
CV (%)
PB1/PB1-I
LLOQ
100
100 (0.005)
99.9
5.4
94 (0.005)
94.0
5.0
QCL
200
188 (0.007)
94.2
3.5
190 (0.012)
94.8
6.3
QCM1
1000
934 (0.039)
93.4
4.1
953 (0.059)
95.3
6.2
QCM2
4000
3972 (0.082)
99.3
2.1
4128 (0.274)
103.2
6.6
QCH
7000
7036 (0.040)
100.5
0.6
7105 (0.328)
101.5
4.6
PB2/PB3
LLOQ
11.9
12.7 (0.001)
106.8
6.6
12.7 (0.001)
107.0
6.4
QCL
23.7
24.0 (0.002)
101.3
6.6
24.7 (0.002)
104.3
7.2
QCM1
118.6
113.8 (0.002)
96.0
2.1
114.6 (0.005)
96.6
4.1
QCM2
474.3
452.4 (0.016)
95.4
3.4
466.0 (0.022)
98.3
4.7
QCH
830.0
801.0 (0.006)
96.5
0.8
793.7 (0.033)
95.6
4.2
accuracy = (found concentration)/(nominal concentration) 100%; precision = (standard deviation)/(average of found concentration) 100%. conc. is concentration; acc. is accuracy; SD is standard deviation.
