5.2.3 Measurement and Monitoring 



More attention needs to be paid to developing rapid, sensitive and precise 

 laboratory techniques involving measurement of substances at ng/1 

 concentrations. This is the cornerstone upon which all the other research 

 questions reset. Without the ability to accurately measure and speciate 

 organotins, the research community will not be able to delineate exact 

 cause and effect relationships in the laboratory or the field. 



5.2.3.1 AnalyHr-al Methods 



It is critical that rapid and inexpensive advanced analytical 

 methodologies or protocols for the determination of ultratrace butyl- and 

 mixed butylmethltin species at the ng/1 level be developed for marine and 

 estuarine waters and in tissues and sediments. 



Studies are needed to provide more information on: 



o What protocols are needed for the development of rapid, 

 inexpensive and accurate analytical methodologies for organotins. 



o What advanced analytical methodologies or protocols for 

 determining butyl- and mixed butylmethyltin species at ng/1 

 concentrations can be used in sediment? 



o What analytical methodologies for determining butyl- or mixed 

 butylmethyltin species at the ng/1 concentrations can be used in 

 tissue? 



5.2.3.2 Standard Reference Materials (SKM's) 



A very high priority should be given to the development and production of 

 certified organotin reference standards or materials for calibration and 

 intercalibration of analytical methods for water, sediment and tissue, as 

 a mixed reference material for TBT and metabolites. 



Studies are needed to provide more information on: 



o What are the necessary standard reference materials necessary for 

 calibration of laboratory instruments and methods to measure TBT 

 at ng/1 concentrations? 



o In addition to standard reference materials for water, sediment, 

 and tissue, what other SFM's are required to adequately monitor 

 TBT in the environment? 



o What additional mixtures of standard reference materials are 

 needed in addition to mixtures of MET, DBT, and TBT? 



V-9 



