Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory-A method supplement for the determination of Fipronil and degradates in water by gas chromatography/mass spectrometry

Sources and preparation of data for assessing trends in concentrations of pesticides in streams of the United States, 1992–2010

“…A schedule is a suite of pesticides to be measured by one or more analytical methods. Four NWQL schedules used the GCMS method for analysis : , 2003: , and 2033: . Schedules 2001 differ only in the location of pesticide extraction-2001 is extracted in the laboratory, whereas 2010 is extracted in the field (Zaugg and others, 1995, p. 43-45).…”

Influence of fipronil compounds and rice-cultivation land-use intensity on macroinvertebrate communities in streams of southwestern Louisiana, USA

“…Procedures used to collect and process water samples followed standard USGS guidelines described by the US Geological Survey (2001), Shelton (1994), Gilliom et al (1995), and Mueller et al (1997). Water samples were analyzed at the USGS National Water Quality Laboratory (NWQL) in Denver, CO, USA, using methods described by Fishman and Friedman (1989), Sandstrom et al (1992), Sandstrom (1995), Zaugg et al (1995), and Madsen et al (2003). The analyses included fipronil and three fipronil degradation products and 15 other pesticides.…”

Causal factors for pesticide trends in streams of the United States: Atrazine and deethylatrazine

“…A subset of the trend results presented in the assessment of national water quality trends by Oelsner et al (2017) was used for this study. The sites were all USGS water quality monitoring sites, and the chemical compounds were analyzed at the USGS National Water Quality Laboratory using gas chromatography-mass spectrometry (GC-MS; Lindley, Stewart, & Sandstrom, 1996;Madsen, Sandstrom, & Zaugg, 2003;Zaugg, Sandstrom, Smith, & Fehlberg, 1995). The pesticide concentration data were prepared for trend analysis by adjusting concentrations to compensate for bias resulting from temporal changes in recovery of the GC-MS analytical method (Martin & Eberle, 2011) and by recensoring routine nondetections by site and pesticide.…”