Table i: Analytical Precisions 



METAL MATRIX % STD DEV N 



Copper Seawater , previously 0.0 3 



extracted, spiked Ippb 



Tissue"", replicate NBS 2.6 8 

 Oyster Tissue preparations 



Zinc Seawater, Intake 2/83 25 3 



Tissue, as above 3.6 8 



Iron Seawater, 5 ppb spike 27 3 



Tissue, as above 5.9 5 



Chromium Seawater, .01 ppb spike 8.7 4 



Tissue, as above 6.5 3 



Lead Seawater, 1 ppb spike 31 4 



* Instrumental determination by Per kin-Elmer AAS with Heated Graphite Atomizer 

 *"' Ins truraenta 1 determination by Instrumentations Laboratory Video 12 AAS-flame 



