U.S. Geological Survey External Qualtiy-Assurance Program Results Reported to the National Atmospheric Deposition Program/National Trends Network and Mercury Deposition Network for 2005-06

摘要

The U.S. Geological Survey (USGS) used seven distinct programs to provide external quality-assurance monitoring for the National Atmospheric Deposition Program/National Trends Network (NTN) and Mercury Deposition Network (MDN) during 2005-06. Overall variability of NTN data was estimated using a co-located-sampler program. Variability and bias of NADP chemical analysis data were estimated using two separate interlaboratory-comparison programs, one for each network. Bias in MDN sample analysis data for total mercury (Hg) was evaluated using a blind-audit program. A separate blind-audit study was conducted in 2006 for the NTN chemical analysis data to evaluate laboratory analytical detection limits. The sensitivity of NADP measurements was evaluated using a field-audit program for NTN and a system blank program for MDN.