1% HNO; using Fisher 1000 ppm standards. Standard additions were 
routinely performed. 
The quality of the tissue trace metal data was assured 
in several ways. These included the analysis of blank samples and 
the measurements of the precision and accuracy of the results. 
Blank concentrations were all well below the element 
concentrations for these samples. Measurements of the precision 
of the trace metals analyses were made by doing replicate analysis 
of a sample of Pitar morrhuana and NRC Lobster Hepatopancreas 
Tissue (Table 2-5). The relative standard deviations of replicate 
analyses of the Pitar morrhuana were less than 20% for all 
elements. 
Results from the analyses of certified NRC Lobster 
Hepatopancreas Tissue also showed excellent accuracy for the trace 
metal analysis methods. The concentrations reported for all eight 
metal elements in the NRC tissue were very similar (91-1083 
agreement) to the NRC values indicating good accuracy (Table 2-5). 
Samples for organic analysis were first sonicated with 
methanol and then three additional times with hexane. The 
methanol/hexane mixture was partitioned via separatory funnel 
techniques. The aqueous methanol was extracted with additional 
hexane, and the combined hexane extracts were decanted through 
Na,SO, and concentrated to 1.0 ml using standard Kuderna-Danish (K- 
D) equipment and techniques. Next, 0.5 ml aliquots of the 
concentrated samples were adjusted to 1.0 ml with acetone and 
eluted with hexane over neutral alumina columns. 
Samples were analyzed for their PCB content according to 
EPA Federal Register Method 608, using a Hewlett Packard 5840A gas 
chromatograph equipped with an electron capture detector and a 30 
m DB 5 fused silica capillary column. The column oven temperature 
was programmed from an initial temperature of 45°C to 290°C using 
a three-step program. The program rate was 7°C/min to 164°C, then 
2°C/min to 214°C, and finally 10°C/min to 290°C. Quantification 
was by the external standard calibration method. 
Tissue samples were screened for the presence of several 
different PCB formulations. These included Aroclors 1016, 1221, 
1232, 1242, 1248, 1254, and 1260. The detection limits presented 
are for Aroclor 1254, commonly found in the marine environment. 
Because each formulation contains different amounts of chlorine, 
the response factors can vary between mixtures. The detection 
limits for Aroclors 1016, 1242, and 1260 were the same as that 
achieved for 1254. The detection limits were higher for the other 
mixtures by factors of 4.0, 2.0 and 1.6 for Aroclors 1221, 1232, 
and 1248, respectively. In» order Sto! “report ae totaley/eeB 
concentration one must add the concentration of all the different 
mixtures. 
12 
