Chemistry Reference
In-Depth Information
tAble 7.6
example bioanalytical lc-ms/ms Qc results
measured concentration (pg/ml)
Qc sample 1
10 ng/µl
Qc sample 2
35 ng/µl
Qc sample 3
1000 ng/µl
Qc sample 4
4400 ng/µl
Qc sample 5
5000 ng/µl
Run 1
11.8
35.7
1009.8
4670.3
5425.0
Run 2
11.1
37.1
1036.0
4796.4
5334.5
Run 3
11.4
35.4
1047.2
4684.9
5180.9
Run 4
10.4
36.0
975.8
4964.3
5241.6
Run 5
10.8
34.6
1047.8
4628.6
5285.6
Run 6
10.9
34.9
986.5
4564.3
5049.0
Run 7
10.9
33.6
971.8
4491.9
5009.2
Run 8
10.8
32.6
960.4
4404.1
4883.7
Run 9
11.3
33.2
956.7
4539.5
5170.8
Run 10
11.4
34.4
977.8
4558.6
4802.7
n
10
10
10
10
10
Target
10.0
35.0
1000.0
4400.0
5000.0
Mean
11.1
34.8
997.0
4630.3
5138.3
Std. Dev.
0.402
1.37
35.45
160.5
199.4
% RSD
3.6
3.9
3.6
3.5
3.9
% Bias
+11.0
-0.6
-0.3
+5.2
+2.8
a
Data representative of typical results obtained for the analysis of quality control samples at 10,
35, 1000, 4400, and 5000 ng/µL. For experimental conditions, see Figure 7.11. The coefficient of
variations (≤4.1%) and biases (≤10.8%) at all concentration levels were within the validation
guidelines.
least four out of every six QC sample results should be within ±15% of their respec-
tive nominal value. Data representative of typical results obtained by LC-MS/MS for
the analysis of QC samples (at concentrations of 10, 35, 1000, 4400, and 5000 pg/
mL of plasma) is listed in Table 7.6. As mentioned previously, for acceptable method
validation, both the imprecision at each concentration level (%RSD), and the accu-
racy (%Bias) must be ≤15% (≤20% at the LLOQ). In Table 7.6, the %RSD (≤3.9%)
and %Bias (≤11.0%) values at all concentration levels were well within the validation
guidelines.
System suitability, sample analysis, acceptance criteria, and guidelines for repeat
analysis or data reintegration should all be performed according to an established
SOP. The rationale for repeat analyses, data reintegration, and the reporting of results
should be clearly documented. Problems from inconsistent replicate analysis, sample
processing errors, equipment failure, or poor chromatography are some of the issues
that can lead to a need to reanalyze samples. In addition, recent interpretations of
bioanalytical guidelines indicate that a certain number of samples be reanalyzed on
a routine basis to ensure method performance (sometimes referred to as “incurred
sample reproducibility”) [36].
