Journal of Chromatography & Separation Techniques
Open Access

Ultra-reliable LC-MS methods: Moving mass spectrometry to the core laboratory

3^rd International Conference on Mass Spectrometry

October 10-11, 2016 Kuala Lumpur, Malaysia

Geoffrey S Rule

ARUP Laboratories, USA

Posters & Accepted Abstracts: J Chromatogr Sep Tech

Abstract :

Many clinical laboratory assays are performed every day at high volumes with only limited numbers of calibration standards. This has lead us to ask whether mass spectrometry based assays are stable enough to perform routine patient sample testing without the need for analyzing multiple calibration standards in a batch-wise fashion. To examine overall assay stability, we categorize sources of variability into ten separate categories (e.g., pipetting and integration errors) and then examine options for reducing overall variability. For example, by making use of a weighted calibration update strategy we have shown that, over a seven month period, we are able to reduce the number of calibration standards analyzed by 80%, over a conventional approach, yet with improved precision for three androgen analytes. The weighting strategy effectively reduces the variance around the calibration curve slope used for quantitation. A second source of variability examined is that resulting from the mass spectrometric determination of analytes to internal standard ratio. In general, we expect this ratio to remain constant during the analytical process but recent studies have shown that partial chromatographic separation of deuterated internal standards can result in differential suppression effects and nonlinear curves. In addition, data presented here shows that the mass spectrometer itself may not always yield the constant area ratios particularly when deuterated internal standards are used. In comparison, we found that 13C labeled internal standards behave better, not only chromatographically, but in terms of MS measurement as well.

Biography :

Email: geoffrey.s.rule@aruplab.com