Determination of oxytocin in a dilute IV solution by LC–MSn
| Autor: | Keith E. Miller, Wendy C. Andersen, Sherri B Turnipseed, Kent C Faul, Christine M. Karbiwnyk |
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| Rok vydání: | 2008 |
| Předmět: |
Chemical Phenomena
Formic acid Electrospray ionization Clinical Biochemistry Analytical chemistry Pharmaceutical Science Oxytocin Mass spectrometry Sensitivity and Specificity High-performance liquid chromatography Mass Spectrometry Analytical Chemistry chemistry.chemical_compound Liquid chromatography–mass spectrometry Drug Discovery Selected ion monitoring Infusions Intravenous Spectroscopy Detection limit Chromatography Molecular Structure Reproducibility of Results Reference Standards Hormones Solutions chemistry Ion trap Chromatography Liquid |
| Zdroj: | Journal of Pharmaceutical and Biomedical Analysis. 48:672-677 |
| ISSN: | 0731-7085 |
| DOI: | 10.1016/j.jpba.2008.06.016 |
| Popis: | The most common drug prescribed to induce labor in the United States is oxytocin, a peptide hormone composed of nine amino acids. Oxytocin is often reconstituted in intravenous (IV) saline solutions at less than 0.05 units ml(-1) (125 ng ml(-1)) to be delivered at 1-4 drops per minute. Existing LC-UV methods for oxytocin do not have sufficient detection limits to quantitate and/or confirm oxytocin in IV solutions without sample concentration. A determinative and confirmatory method for oxytocin was developed using an LC-MS(n) ion trap instrument with an electrospray ionization (ESI) interface in positive ion mode. Separation was achieved on a C-18 column using an isocratic elution of water with 50% acetonitrile (v/v) and water with 0.05% formic acid (v/v) at a flow rate of 250 microl min(-1). Data was acquired from the selected ion monitoring (SIM) of the precursor ion (m/z 1007.3) and MS(2) scans from the collision induced dissociation of m/z 1007.3 at 30% collision energy. In this method, MS(2) full scans were utilized to obtain three structurally significant ions for the unambiguous identification of oxytocin. Calibration standards, prepared in de-ionized water from 0.006 to 0.046 units ml(-1), were linear with an R(2) value of 0.9983. The methods LOD and LOQ were 0.00084 and 0.0029 units ml(-1) (2 and 7 ng ml(-1)), respectively. This LC-MS(n) method was used to determine the amount of oxytocin in a 0.04 units ml(-1) clinical sample that was prepared in 0.9% sodium chloride IV solution. |
| Databáze: | OpenAIRE |
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