Automated, fast and sensitive quantification of drugs in blood by liquid chromatography-mass spectrometry with on-line extraction: immunosuppressants.
We developed a universal LC-mass spectrometry assay with automated online extraction (LC/LC-MS) to quantify the immunosuppressants cyclosporine, tacrolimus, sirolimus and SDZ-RAD alone or in combination in whole blood. After protein precipitation, samples were loaded on a C18 extraction column, were washed and, after activation of the column-switching valve, were backflushed onto the C8 analytical column. [M+Na]+ ions were detected in the selected ion mode. For tacrolimus, sirolimus and SDZ-RAD, the assay was linear from 0.25 to 100 microg/l and for cyclosporine from 7.5 to 1250 microg/l (all r2>0.99). Analytical recovery was >85% and, in general, inter-day, intra-day variability for precision and accuracy were <10%.
Christians
U
U
Department of Biopharmaceutical Sciences, University of California, San Francisco 94143-0446, USA. uwec@itsa.ucsf.edu
Jacobsen
W
W
Serkova
N
N
Benet
L Z
LZ
Vidal
C
C
Sewing
K F
KF
Manns
M P
MP
Kirchner
G I
GI
D001331:Automation; D002138:Calibration; D002853:Chromatography, Liquid / Q000379:methods*; D007166:Immunosuppressive Agents / Q000097:blood*; D013058:Mass Spectrometry / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D007166:Immunosuppressive Agents