title: In-situ measurements of Cu in an estuarine environment using a portable spectrophotometric analysis system.
abstract: Application of a portable in-situ spectrophotometric analysis system for the measurement of Cu in estuarine environments is described in this work. Our spectrophotometric elemental analysis system (SEAS) used for in-situ observations of Cu concentrations is capable of fully autonomous or user-controlled operations. The optical cells used in SEAS systems are flexible liquid core waveguides (LCWs) with optical path lengths as long as 5 m. The 1-m waveguide used in the present study provided a 3.0 nM detection limit and a 5.0% relative standard deviation for a 25 nM copper sample. Analysis times range between 1 and 5 min, allowing for acquisition of data on scales appropriate to the highly dynamic biogeochemical nature of copper in the coastal environment. Field deployments of SEAS-Cu in Tampa Bay, FL, showed low Cu concentrations near the mouth of the estuary (3-4 nM), with elevated concentrations (approximately 25 nM) in anthropogenically impacted regions of the bay (e.g., marinas and areas adjacent wastewater treatment plants). Transect data between Tampa Bay and a deep water harborage exhibited copper concentrations ranging between 5 and 50 nM.
authors.affiliation: College of Marine Science, University of South Florida, Saint Petersburg, Florida 33701, USA.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Callahan
authors.forename: Eric A
authors.initials: EA
authors.lastname: Kaltenbacher
authors.forename: Robert H
authors.initials: RH
authors.lastname: Byrne
mesh_terms: D003300:Copper / Q000032:analysis*; D017753:Ecosystem; D004784:Environmental Monitoring / Q000295:instrumentation*; D055593:Geological Phenomena; D005844:Geology; D013053:Spectrophotometry / Q000379:methods; D014873:Water Pollutants / Q000032:analysis*
chemical_list: D014873:Water Pollutants; D003300:Copper