64 / 658
4. Precision
A) CSS samples: Precision was first assessed with spiked CSS
at two concentration levels (12 and 300 pg/mL). Inter-
(n=15) and intra-batch (n=5) CV values ranged between
1.6% to 12.5% (Table 2).
B) Pooled human plasma samples: Precision was also as-
sessed with a spiked human plasma pool (35.4 pg/mL
of E1 and 18.1 pg/mL of E2, n=5) and the determined
intra-batch CV was 2.2% and 3.6% for E1 and E2,
respectively.
Retention Time (min)
Intensity
2.1
2.4
2.7
3.0
3.3
3.6
3.9
0
82
E1:
E2:
SRM: 269 145
3.5 pg/mL
SRM: 271 183
4.4 pg/mL
Figure 4. SRM chromatograms of E1 and E2 at their LLOQ in spiked CSS
E1
E2
Charcoal Stripped Serum
Low (12 pg/mL)
High (300 pg/mL)
Low (12 pg/mL)
High (300 pg/mL)
Batch 1 Intra-assay Precision (n=5, %)
7.1
6.9
9.4
6.7
Batch 2 Intra-assay Precision (n=5, %)
5.5
1.6
12.5
3.0
Batch 3 Intra-assay Precision (n=5, %)
7.2
4.9
8.0
3.1
Batch 1-3 Inter-assay Precision (n=15, %)
7.3
4.7
10.9
4.4
Spiked Pooled Plasma
E1 (35.4 pg/mL) E2 (18.1 pg/mL)
Precision (n=5, %)
2.2
3.6
Table 2. Precision data