Quantitative determination of the polypeptide motilin in rat plasma by externally calibrated liquid chromatography/electrospray ionization mass spectrometry
Article first published online: 6 JAN 2004
Copyright © 2003 John Wiley & Sons, Ltd.
Rapid Communications in Mass Spectrometry
Volume 18, Issue 3, pages 293–298, 15 February 2004
How to Cite
Delinsky, D. C., Hill, K. T., White, C. A. and Bartlett, M. G. (2004), Quantitative determination of the polypeptide motilin in rat plasma by externally calibrated liquid chromatography/electrospray ionization mass spectrometry. Rapid Commun. Mass Spectrom., 18: 293–298. doi: 10.1002/rcm.1328
- Issue published online: 6 JAN 2004
- Article first published online: 6 JAN 2004
- Manuscript Revised: 18 NOV 2003
- Manuscript Accepted: 18 NOV 2003
- Manuscript Received: 8 JUL 2003
We present a method for the quantitation of motilin from rat plasma by protein precipitation and liquid chromatography/mass spectrometry (LC/MS). Using external calibration, the method was linear over the concentration range 10–1000 ng/mL with an initial sample volume of 150 μL. The LC system included a C18 column with a 300 Å pore size. A linear gradient was used with a mobile phase consisting of water and acetonitrile, each with 0.2% acetic acid and 0.02% trifluoroacetic acid. Motilin was detected with the mass spectrometer in positive ion mode monitoring the 4+ charge state at m/z 675.5. The approximated limit of detection was less than 1 ng/mL and the lower limit of quantitation (LLOQ) was 10 ng/mL. The method showed a high degree of precision and accuracy both within and between runs at five validation points, including the LLOQ. Copyright © 2004 John Wiley & Sons, Ltd.