Filters: Tags: Biosolids (X)2 results (8ms)
Multiresidue extraction of current-use pesticides from complex solid matrices using energized dispersive extraction with analysis by gas and liquid chromatography tandem mass spectroscopy
A multiresidue method for solids (i.e., soil, sediment, sludge) was developed and evaluated for the analysis of pesticides and pesticide degradates. Initially, a well characterized soil was used to determine the recovery of target compounds using an Energized Dispersive Guided Extraction (EDGE) system with two extraction solvents, acetonitrile and 1:1 (v/v) hexane:acetone. Extracts were cleaned using solid-phase extraction (SPE) with graphitized carbon cartridges and three elution solvents, acetonitrile, dichloromethane, and 1:1 (v/v) dichlormethane:ethyl acetate. The individual SPE elutions from the two extraction solvents were analyzed separately via GC-MS/MS and LC-MS/MS for 210 pesticides and pesticide transformation...
CAST Data Input Disaggregation from County and Land-River Segment Scale to National Hydrography Dataset Plus, Version 1.1
The detrimental effects of excess nutrients and sediment entering the Chesapeake Bay estuary from its watersheds have necessitated regulatory actions. Federally-mandated reductions are apportioned to bay jurisdictions based on the U.S. Environmental Protection Agency's Chesapeake Bay Time-Variable Watershed Model (CBPM). The Chesapeake Assessment Scenario Tool (CAST version CAST-19; cast.chesapeakebay.net; Chesapeake Bay Program, 2020) is a simplified, on-line version of the Phase 6 CBPM that simulates watershed nutrients delivery to the estuary using the original model's annual land-surface nutrient source and removal inputs and time-averaged climatological forecasting. Because it runs much faster than the CBPM,...