Intercomparison of Instrumental Methods Using Model II Regression

COLLEEN MARCIEL ROSALES, Nicholas E. Brunk, Nicole Hyslop, Nicholas Spada, University of California, Davis

     Abstract Number: 528
     Working Group: Instrumentation and Methods

Abstract
X-Ray fluorescence spectroscopy (XRF) and Inductively Coupled Mass Spectroscopy (ICP-MS) are both experimental techniques for the elemental characterization of particulate matter (PM). The reproducibility of estimations of sample elemental composition between the two techniques is not well understood. Using data collected from an ambient monitoring network, we have compared measurements using both techniques on the same samples, specifically assessing the elemental composition by quantifying concentrations of 29 elements in 549 samples using both techniques. Instrumental intercomparison was quantified via the use of Model II statistical regression techniques that, unlike OLS regression, account for experimental error in both variates without the asymmetry of choosing a given reference instrument.