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51. Determination of telmisartan in human blood plasma: Part II: Liquid chromatography-tandem mass spectrometry method development, comparison to immunoassay and pharmacokinetic study

Author

Hempen, C.M., Gläsle-Schwarz, Liane, Kunz, Ulrich, and Karst, U.

Subjects
IR-74292
Abstract

A new liquid chromatography/atmospheric pressure chemical ionization-tandem mass spectrometry (LC/APCI-MS/MS) method with on-line sample clean-up for the determination of telmisartan in human blood plasma is presented. This technique is compared to a previously introduced enzyme-linked immunosorbent assay (ELISA), where fluorescence is used as detection method. For the LC/MS method applying an internal calibration via a deuterated internal standard, the limit of detection was 0.3 ng/mL, the limit of quantification was 0.9 ng/mL and the linear range extended from 0.9 to 1000 ng/mL. Forty-eight plasma samples from four healthy volunteers were analyzed in a pharmacokinetic study to obtain data for the method comparison. As a result, these two new and independent analytical methods for the determination of telmisartan in human blood plasma proved to yield comparable results for the amount of analyte.

Published
2006

56. Kinetic study of an on-chip isocyanate derivatization reaction by on-line nano-esi ms

Author

Brivio, M., Liesner, A., Oosterbroek, R.E., Verboom, Willem, Karst, U., van den Berg, Albert, Reinhoudt, David, Jensen, K.F, Han, J., Harrison, D.J., Voldman, J., Faculty of Science and Technology, and Molecular Nanofabrication

Subjects
Micro-reactor, EWI-19992, nano-ESI MS, METIS-224693, real-time monitoring, IR-52865, Reaction kinetics
Abstract

A high-throughput method is presented for the study of reaction kinetics by nano- electrospray ionization mass spectrometry (nano-ESI MS). The reaction of propyl isocyanate (2), benzyl isocyanate (3), and toluene-2,4-diisocyanate (4) with 4-nitro-7- piperazino-2,1,3-benzoxadiazole (NBDPZ) (1) to yield the corresponding urea derivatives (5) was carried out in a continuous flow glass microchip. Real-time monitoring of the reactions was done by nano-ESI MS. Rate constants of 1.6 ⿣ 104 M-1 min-1, 5.2 ⿣ 104 M-1 min-1, and 2.5 ⿣ 104 M-1 min-1 were determined for isocyanate 2, 3 and 4, respectively.

Published
2005

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