3H/inninen 0 O, Koistinen K J, Kousa A, et al. Quantitative analysis of environmental factors in differential weighing of blank Teflon filters [ J ]. J Air Waste Manag Assoc, 2002, 52 (2): 134-139.
6National Institute for Occupational Safety and Health. Guidelines for air sampling and analytical method development and evaluation [ S ]. Washington : U.S. Government Printing Office, 1995.