Biomedical Engineering Reference
In-Depth Information
Fig. 11
Typical chromatograms showing injection volume (I.V.) optimization for pooled serum
spiked with 100 pg/mL of 1,25(OH)2VitD3 and extracted by selective SPE. The I.V. was
(
a
) 0.2 m L; (
b
) 0.6 m L; (
c
) 3 mL; and (
d
) 9.5 mL. A 15 cm × 0.5 mm I.D. capillary column (manu-
facturer suggestion I.V. was 0.2-0.4 mL) was used for separation. Using the selective SPE and a
sample focusing approach before the separation, a large I.V. was enabled without compromising
chromatographic performance and with substantially increased sensitivity (Reproduced with
permission from American Chemical Society)