Development of a Quick TBT Analytical Method
Final Report
to the
National Shipbuilding Research (NSRP)
Environmental Science and Technology Program
by
Center for Advanced Ship Repair and Maintenance
222 East Main Street
Norfolk, VA 23506

Executive Summary
Concern about the toxic effect of tributyltin have caused the Commonwealth of Virginia through the Department of Environmental Quality to promulgate a Virginia Pollutant Discharge Elimination System (VPDES) discharge standard of 50 parts per trillion (pptr or ng/L). In addition to this action, an international ban on the use of TBT paints is scheduled for 2008. These actions as well as the interest by some shipyards in ISO 14001 certification have focused attention on removing tributyltin from shipyard discharges to the environment. One manner in which shipyards can mitigate TBT discharges from shipyard waters is through treatment of waters containing TBT and testing of waters thought to contain TBT. In order to determine whether a water contains TBT or if a water is undergoing treatment to know whether adequate treatment has been achieved, a fast turnaround method is needed. A fast analytical method is desirable since holding water at a shipyard can negatively impact shipyard production and impose a cost of containment. To address these issues, a study was conducted to develop a “Fast-TBT Method” that would allow analysis of aqueous samples that could produce analytical results in less than half a day from the time a sample was received. Specifically for a calibrated instrument, the goal was to develop a method that would allow a single measurement of a sample in less than fifteen minutes. The effort described in this report meets the goals established for the method. A single injection/stripping of a sample can be conducted in less than 15 minutes and using sample triplicates and standard additions for quality assurance and quality control. The samples included in this effort included high ionic strength sonar dome samples as well as ship hull wash water samples. Comparison of sonar dome samples split with a laboratory using the Virginia regulatory -approved provided initial data that the Fast-TBT Method provided comparable results to the approved method. An inter-laboratory (round robin) comparison study was conducted as a follow-on effort to further attempt to validate the Fast-TBT Method. In this effort, twenty TBT-spiked samples were created in one laboratory, split and handled identically, and delivered to participating laboratories over the course of a four-week period. These (blind) samples ranged from less than 10 ng/L (pptr) up to approximately 10,000 ng/L (pptr). Analytical results were delivered to a third party not directly connected to the participants in the inter-laboratory comparison and statistically analyzed. The results indicate that the methods were comparable in the range at which shipyards would likely be discharging treated (or naturally low concentration) TBTcontaining water and that regulatory acceptance of the method has a high probability of occurring if a more extensive effort (number of participants and a number of sample matrices) is employed.