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Lake Wales Ridge Ground-Water Monitoring Study


TARGET ANALYTES
AND LABORATORY METHODS

 

  • Laboratory analyses for the project have been performed by the FDACS Pesticide Laboratory:
    http://www.flaes.org/pesticide/PesticideSampelAnalysis.html,
    the FDACS Food Laboratory:
    http://www.doacs.state.fl.us/fs/labs.html#fl,
    and the SWFWMD Laboratory and contract laboratories.
    The pesticides and pesticide degradates were analyzed using gas chromatography with a nitrogen phosphorous detector (NPD), high-performance liquid chromatography (HPLC) [both UV/VIS and post column derivatization], liquid chromatography/mass spectroscopy (LC/MS) and ion chromatography, and included both standard USEPA methods and FDACS custom methods for selected compounds. Concentrations of organic compounds in spiked samples generally were within about 75 to 105 percent of expected concentration, with the exception of deisopropyl atrazine, which yielded about 50 percent recovery.

     
  • Target analytes evaluated quarterly include field measurements, basic water chemistry, nutrients, pesticides and pesticide degradates, and selected trace constituents.  Target analytes and the analyzing laboratories are listed in table 2.  Limited reconnaissance sampling has been performed to assess the occurrence of additional simazine degradates (table 5).

     
  • Method detection limits for pesticides, pesticide degradates, and selected target analytes are listed in table 3.
The Southwest Florida Water Management District's mobile laboratory provides for 'clean-water' (parts-per-billion concentrations) sampling protocols, and direct input of field measurements into a computer data base during the well purge. - click to enlarge
Prior to sample collection, ground-water temperature, pH, specific conductance, turbidity, and dissolved oxygen are monitored during the purge of well water using a submersible pump, and probes mounted in a flow-through chamber. - click to enlarge

 

 

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