3.5.3 Phase III confirms the identity of toxicants that are provision- 

 ally identified in Phases I and II. We employed two methods from the 

 suite of Phase III techniques suggested by Mount (1988): (1) We corre- 

 lated toxicity with measured concentrations of suspect chemicals in our 

 test solutions, and (2) we compared the relative sensitivity of our test 

 species to known toxicants and to our samples. The correlation analy- 

 sis was performed on the toxicity tests which used the standard refer- 

 ence animal, C. dubia. As mentioned earlier, the correlation analyses 

 used total ammonia concentrations, rather than un-ionized ammonia con- 

 centrations. The drift in pH during the toxicity tests made it impossi- 

 ble to calculate un-ionized ammonia concentrations based on measurements 

 of total ammonia and the pH of the test solutions. 



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