Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory : determination of pesticides in water by graphitized carbon-based solid-phase extraction and high-performance liquid chromatography/mass spectrometry /

Shipping list no.: 2002-0081-P.Includes bibliographical references (p. 72-73).Mode of access: Internet

Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory : determination of moderate-use pesticides and selected degradates in water by C-18 solid-phase extraction and gas chromatography/mass spectrometry /

"Laboratory methods (schedules) 2002 and 2011.""U.S. Geological Survey method 0-2002-01."Includes bibliographical references (p. 63-64).Mode of access: Internet

Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory : determination of organic plus inorganic mercury in filtered and unfiltered natural water with cold vapor-atomic fluorescence spectrometry /

Shipping list no.: 2001-0307-P.Includes bibliographical references (p. 15-16).Mode of access: Internet

Quality-assurance results for routine water analyses in U.S. Geological Survey laboratories, water year 1997 /

Chiefly charts.Includes bibliographical references (p. 37-38).Mode of access: Internet

Quality-assurance results for routine water analyses in U.S. Geological Survey laboratories, water year 1998 /

Includes bibliographical references (p. 37-38).Mode of access: Internet