We consider problems of quantifying and monitoring accuracy and precision of measurement in mass spectrometry, particularly in contexts where there is unavoidable day-to-day/period-to-period changes in instrument sensitivity. First, we consider the issue of estimating instrument sensitivity based on data from a typical calibration study. Simple method-of-moments methods, likelihood-based methods, and Bayes methods based on the one-way random effects model are illustrated. Then, we consider subsequently assessing the precision of an estimate of a mole fraction of a gas of interest in an unknown. Finally, we turn to the problem of ongoing measurement process monitoring and illustrate appropriate setup of Shewhart control charts in this application.
Available at: http://works.bepress.com/stephen_vardeman/25/
This is an Accepted Manuscript of an article published by Taylor & Francis in Quality Engineering on February 15, 2007, available online: http://www.tandfonline.com/10.1080/08982110600567541.