Crocker Nuclear Laboratory uses a custom built energydispersive X-ray fluorescence system with a molybdenum anode to provide routine analysis of elements from nickel to zirconium and lead in Interagency Monitoring of Protected Visual Environments (IMPROVE) samples. Standard methods are used to ensure accuracy and statistical control of the data, including repeated analysis of singleelement standards, standard reference materials, and selected actual samples from the IMPROVE network. This paper compares the short-term (week) precision and longterm (2-yr) reproducibility revealed by the actual sample reanalyses. Currently reported analytical uncertainties are shown to predict actual 2-yr reproducibility within a factor of 2.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.