Table 2. Precision studies for the LC-MS/MS (reference method).
| 25(OH)D2/D3 | Serum pools* | Within-run | Between-run | ||||
|---|---|---|---|---|---|---|---|
|
Mean (ng/mL)† |
SD‡ |
CV (%)§ |
Mean (ng/mL) |
SD |
CV (%) |
||
| 25(OH)D2 | Pool 1 | 10.3 | 0.8 | 7.4 | 9.5 | 0.8 | 5.1 |
| Pool 2 | 20.1 | 1.4 | 6.9 | 19.2 | 1.4 | 5.1 | |
| Pool 3 | 27.8 | 1.7 | 6.0 | 24.9 | 1.7 | 3.9 | |
| 25(OH)D3 | Pool 1 | 11.5 | 0.8 | 8.7 | 10.7 | 0.9 | 8.8 |
| Pool 2 | 21.6 | 1.4 | 7.3 | 21.2 | 1.4 | 6.4 | |
| Pool 3 | 32.3 | 1.7 | 6.9 | 31.5 | 1.5 | 4.7 | |
*Three serum pools mixed with different 25(OH)D2 (25[OH]D2 spiked) and 25(OH)D3 concentration levels; †mean concentration in nanograms per milliliter (ng/mL x 2.5 = nmol/L); ‡standard deviation; §coefficient of variation in percent.