Quantification of Sirolimus by Liquid Chromatography-Tandem Mass Spectrometry Using On-Line Solid-Phase Extraction
-
Michael Vogeser
Abstract
Quantification of the new immunosuppressant sirolimus (syn. rapamycin; Rapamune®) in whole blood by chromatography is essential for its clinical use since no immunoassay is available although monitoring is mandatory. Here we report on a rapid and convenient liquid chromatography (LC)-tandem mass spectrometry method and describe our practical experience with its routine use.
Whole blood samples were hemolyzed and deproteinized using an equal volume (150 μl) of a mixture of methanol/zinc sulfate solution containing the internal standard desmethoxy-rapamycin. After centrifugation, the clear supernatants were submitted to an on-line solid-phase extraction procedure using the polymeric Waters Oasis HLB® material, with elution of the extracts onto the analytical column in the back-flush mode by column switching. For analytical chromatography a RP-C18 column was used with 90/10 methanol/2 mM ammonium acetate as the mobile phase. A 1:10 split was used for the transfer to the mass spectrometer, a Micromass Quattro LC-tandem mass spectrometry system equipped with a Z-spray® source and used in the positive electrospray ionization mode. The following transitions were recorded: sirolimus, 931>864 m/z, and desmethoxy-rapamycin (I.S.), 901>834 m/z. The analytical running time was 5 min, including on-line extraction.
The method has a linear calibration curve (r>0.99; range 1.6–50 μg/l) and is rugged and precise with monthly CVs <7% at a sirolimus concentration of 13.1 μg/l in routine use; the instrumentation proved to be reliable and required minimal maintenance.
Copyright © 2002 by Walter de Gruyter GmbH & Co. KG
Artikel in diesem Heft
- Editorial
- Growing Significance of Myeloperoxidase in Non-infectious Diseases
- Serum Paraoxonase Activity and the Extent of Lipid Peroxidation Are not Affected by Increased Levels of Human Apolipoprotein A-I: Studies in Transgenic Mice
- Relationship between the Sialic Acid Content of Low-Density Lipoprotein (LDL) and Autoantibodies to Oxidized LDL in the Plasma of Healthy Subjects and Patients with Atherosclerosis
- The Presence of Heparin-Platelet Factor 4 Antibodies as a Marker of Hypercoagulability during Hemodialysis
- Clinical Evaluation of Changes in the Morphology of Eosinophils
- The n-3 and n-6 Polyunsaturated Fatty Acid Composition of Plasma Phospholipids in Pregnant Women and Their Infants. Relationship with Maternal Linoleic Acid Intake
- Quantification of Sirolimus by Liquid Chromatography-Tandem Mass Spectrometry Using On-Line Solid-Phase Extraction
- The Effects of Affinity-Purified Anti-DNA Antibodies Derived from Patients with Systemic Lupus Erythematosus on the Fluorescent Antinuclear Antibody Assay Using HEp-2 Cells
- Relationships between Serum Markers of Monocyte/Macrophage Activation in Type 1 Gaucher's Disease
- Gender Differences in C-Reactive Protein Concentrations - Confirmation with Two Sensitive Methods
- Serum Cholinesterase Activity in Patients with Burns
- Serum Lipids and Apolipoproteins in Patients with Psoriasis
- Reference Intervals for a Complete Blood Count Determined on different Automated Haematology Analysers: Abx Pentra 120 Retic, Coulter Gen-S, Sysmex SE 9500, Abbott Cell Dyn 4000 and Bayer Advia 120
- Science, Alchemy and Light: Paintings by Joseph Wright of Derby
- Approved IFCC Reference Method for the Measurement of HbA1c in Human Blood
- Meetings and Awards
Artikel in diesem Heft
- Editorial
- Growing Significance of Myeloperoxidase in Non-infectious Diseases
- Serum Paraoxonase Activity and the Extent of Lipid Peroxidation Are not Affected by Increased Levels of Human Apolipoprotein A-I: Studies in Transgenic Mice
- Relationship between the Sialic Acid Content of Low-Density Lipoprotein (LDL) and Autoantibodies to Oxidized LDL in the Plasma of Healthy Subjects and Patients with Atherosclerosis
- The Presence of Heparin-Platelet Factor 4 Antibodies as a Marker of Hypercoagulability during Hemodialysis
- Clinical Evaluation of Changes in the Morphology of Eosinophils
- The n-3 and n-6 Polyunsaturated Fatty Acid Composition of Plasma Phospholipids in Pregnant Women and Their Infants. Relationship with Maternal Linoleic Acid Intake
- Quantification of Sirolimus by Liquid Chromatography-Tandem Mass Spectrometry Using On-Line Solid-Phase Extraction
- The Effects of Affinity-Purified Anti-DNA Antibodies Derived from Patients with Systemic Lupus Erythematosus on the Fluorescent Antinuclear Antibody Assay Using HEp-2 Cells
- Relationships between Serum Markers of Monocyte/Macrophage Activation in Type 1 Gaucher's Disease
- Gender Differences in C-Reactive Protein Concentrations - Confirmation with Two Sensitive Methods
- Serum Cholinesterase Activity in Patients with Burns
- Serum Lipids and Apolipoproteins in Patients with Psoriasis
- Reference Intervals for a Complete Blood Count Determined on different Automated Haematology Analysers: Abx Pentra 120 Retic, Coulter Gen-S, Sysmex SE 9500, Abbott Cell Dyn 4000 and Bayer Advia 120
- Science, Alchemy and Light: Paintings by Joseph Wright of Derby
- Approved IFCC Reference Method for the Measurement of HbA1c in Human Blood
- Meetings and Awards
