The PIs propose to design and field-test in situ autonomous sensors for three marine pollutants: copper, zinc and cadmium. Objectives for the sensors include the ability to accurately measure concentrations in the range of 0.5-250 nM with a precision of at least 6%. These proposed sensors will be based on the well-tested DigiSCAN technology developed in the Chemical Sensors lab at the Monterey Bay Aquarium Research Institute (MBARI) and currently being commercialized by YSI. This is a versatile, compact sensor system for in situ wet chemistry that uses micro solenoid pumps for sample uptake and reagent dispensing. To date, DigiSCAN has been configured for colorimetric detection of nitrate and phosphate. The work outlined in this proposal aims to adapt this instrumentation to utilize published chemiluminescent (Cu) and fluorometric (Zn and Cd) detection methods for copper, zinc and cadmium. Specifically, this will: (1) construct chemiluminescent (PMT) and fluorometric detectors for DigiSCAN, (2) adapt published flow injection analysis methods for Cu, Zn and Cd analysis to the DigiSCAN hardware, and (3) deploy the instrument in anthropogenically impacted and relatively pristine coastal environments. This development will also enable the analysis of other metals such as iron and cobalt (chemiluminescence) as well as other analytes of interest such as ammonia and aluminum (fluorescence).
