Katharina Kern (Presenter)
RECIPE Chemicals + Instruments GmbH
Bio: I graduated in 2009 from the University of Applied Science in Nuremberg (Germany) with a Diploma Degree for Biochemical Engineering. After my studies I was working in a privately owned lab for 5 years, developing LC-MS/MS methods for small molecules to be used in big studies. In January 2014 I started working in the R&D department of RECIPE Chemicals + Instruments GmbH. I am responsible for the development and validation of methods for therapeutic drug monitoring.
Authorship: Katharina Kern, Anke Deden, Irene Doering
RECIPE Chemicals + Instruments GmbH, Dessauerstr. 3, 80992 Munich, Germany
| Short Abstract RECIPE’s CE IVD certified ClinMass® LC-MS/MS Complete Kits – Free Metanephrines in Plasma allow quantitation of metanephrine, normetanephrine and 3-methoxytyramine in human plasma after on-line or off-line sample preparation. Both kits include simultaneous extraction and concentration, while the separation and mass selective detection is achieved using LC-MS/MS. The method shows outstanding validation results for all analytes. Close agreement of analyte concentrations with results reported for RCPAQAP proficiency testing scheme could be obtained. With RECIPE’s MS11000/MS11100 a fast, easy and reliable analysis of plasma free metanephrines has been realized which is very well suited for clinical routine analysis. |
Long Abstract
Quantitation of plasma free metanephrines (PFM) using liquid chromatography tandem mass spectrometry (LC-MS/MS) is recommended for sensitive and specific diagnosis of the catecholamine-producing tumors pheochromocytoma and paraganglioma. PFM comprise the O-methylated forms of catecholamines, namely normetanephrine, metanephrine and 3-methoxytyramine. Because of their polar nature, their low molecular weight and their low physiological concentration in human plasma, the analytical measurement is challenging.
Up to now no diagnostic LC-MS/MS complete kit is commercially available for use in clinical routine analysis.
In order to simplify LC-MS/MS analysis of PFM and to improve the standardization of the routine measurement, RECIPE’s ClinMass® LC-MS/MS Complete Kits – Free Metanephrines in Plasma (MS11000, MS11100) have been developed. These kits enable either an on-line or an off-line cleanup including simultaneous extraction, concentration, separation and mass selective detection of normetanephrine (NMN), metanephrine (MN) and 3-methoxytyramine (3-MT). Since the on-line kit requires an LC system with two binary pumps and a six-port switching valve, the off-line cleanup can be done with the common lab accessories – there is no need for a second binary pump or a six-port switching valve.
After a simple and effective protein precipitation further purification and analyte enrichment is achieved with on-line SPE using a trap column. Via a six-port switching valve the analyte fraction is transferred from the trap column to the analytical column for chromatographic separation of the analytes (total run time 6 minutes).
Using the off-line kit, a simple dilution of the sample is followed by loading, washing and eluting of the analytes from the SPE cartridge. There is no need for a further evaporation step and the homogenized sample can be chromatographically separated using an LC-MS/MS system within a total run time of 4 minutes.
For accurate and precise quantitation, the Complete Kits include multi-level serum calibrators (5 levels) and multi-level serum controls (3 levels) for quality control. Matrix effects are compensated using stable isotope labelled internal standards.
Linearity was found over the range 0.06 – 54 nmol/L for normetanephrine, 0.03 – 27 nmol/L for metanephrine and 0.02 – 61 nmol/L for 3-methoxytyramine (r2 > 0.99). The LLOQs achieved by this method were 0.06, 0.03 and 0.02 nmol/L, respectively. The coefficients of variation for the intra-assay and inter-assay precision were <6.1%. Close agreement of analyte concentrations with results reported for RCPAQAP (Royal College of Pathologists of Australasia, Quality Assurance Program) proficiency testing scheme could be obtained.
With RECIPE’s CE IVD certified ClinMass® Complete Kits highly sensitive and selective methods have been realized which enable fast, easy and reliable analysis of PFM and are hence very well suited for clinical routine analysis.
References & Acknowledgements:
| Description | Y/N | Source |
| Grants | no | |
| Salary | yes | RECIPE Chemicals + Instruments GmbH |
| Board Member | no | |
| Stock | no | |
| Expenses | no |
IP Royalty: no
| Planning to mention or discuss specific products or technology of the company(ies) listed above: | yes |