Table IV.
Stability of PEth in whole blood, dried blood spots, and extracted samples.
| Sample/Stability Condition | CV (%) | Deviation from Nominal (%) | Difference from Control (%) | n | |
|---|---|---|---|---|---|
| Whole Blood1 | 3.6 | NA | 2.2 | 3 | |
| Dried Blood Spots | |||||
| Room Temperature2 |
QL | 4.0 | 0.8 | 7.7 | 3 |
| QH | 7.0 | 1.8 | 9.4 | 3 | |
| Freeze-Thaw3 | QL | 5.9 | 2.7 | 1.4 | 3 |
| QH | 9.4 | 13.1 | 2.7 | 3 | |
| Long-Term4 | QL | 5.4 | 10.4 | 12.9 | 3 |
| QH | 2.3 | 7.3 | 9.4 | 3 | |
| Extracted Samples5 | |||||
| Autosampler | QL | 10.6 | 8.0 | 0.6 | 6 |
| QH | 2.0 | 5.5 | 0.4 | 6 | |
| Reinjection | QL | 11.3 | 0.9 | 7.7 | 6 |
| QH | 2.1 | 4.6 | 0.4 | 6 | |
1
Participant whole blood containing PEth was kept at room temperature for 4 days.
2
DBS were kept at room temperature for 7 days.
3
Three freeze-thaw cycles were evaluated with DBS kept at −80 C.
4
Long-term stability was evaluated at 228 days with DBS kept at −80 C.
5
Extracted samples were evaluated after 15 days of storage at 15 C.