MINIATURIZED AUTONOMOUS CHEMICAL ANALYZERS
Ship-based oceanic surveys of trace metals have and will continue to advance our understanding of their cycles. However, many critical processes occur at spatial and temporal scales that cannot be resolved using the infrequent, fixed interval sampling of oceanographic cruises and shore-based monitoring programs. To investigate high-frequency signals and monitor trace metal and nutrient dynamics in remote regions, it is necessary to develop automated sensors and analyzers that can be deployed in situ for long periods. A promising approach to upgrade existing chemical methods is to miniaturize and automate the various steps involved in the spectroscopic determination (absorbance, fluorescence and chemiluminescence) of metals and nutrients using microfluidics. Microfluidic are an exciting technology for development in chemical oceanography, since they allow the downscaling of conventional reagent-based assays down to the microliter level in compact and fully automated devices.
The Chemical Oceanography Lab recently acquired a micro-Sequential Injection Lab-On-Valve (µSI-LOV) analyzer, a microfluidic instrument with a demonstrated capability to perform all the analytical steps (pre-concentration, derivatization and spectroscopic detection) required to measure trace metals (e.g., Zn) at sub-nanomolar levels in seawater using only tens of microliters of reagent(s) per analytical cycle. We plan to expand the monitoring portfolio of µSI-LOV to Fe, Al, Cu, Co, Mn and nutrient determinations (nitrate, phosphate and silicate). Once new methods are validated in the lab, we will work with engineers and commercial partners to develop a field deployable µSI-LOV package, which will be tested in Monterey Bay and beyond.
Prospective students with an analytical chemistry inclination or interest in oceanographic method development are highly encouraged to discuss opportunities in the Chemical Oceanography Lab.