1. 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 Publication/Creation: Denver, Colo. : U.S. Dept. of the Interior, U.S. Geological Survey, 2001 Resource Type: Book Access & Availability: Loading
2. Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory : determination of wastewater compounds by polystyrene-divinylbenzene solid-phase extraction and capillary-column gas chromatography/mass spectrometry Publication/Creation: Denver, CO : National Water Quality Laboratory, U.S. Geological Survey, 2002 Resource Type: Book Access & Availability: Loading