The International Mussel Watch 



valuable information is gained on the composition of the usually complex mixture of congeners 

 representing "total PCB". This information is the basis for understanding the sources, 

 distribution, transport pathways, sinks, degradation mechanisms and effects on organisms of these 

 individual congeners and groups of congeners. It eliminates most of the ambiguities associated 

 with the use of packed columns. 



2 . Sample Preparation in the Field 



For ancillary data to be recorded prior to initiating the following procedures see The Manual 

 on Specimen Collection Methods and Data Recording (Appendix C). 



All implements should be cleaned thoroughly with detergent obtained locally and rinsed 

 with copious amounts of fresh water, or clear seawater not visibly contaminated with panicles, oil 

 slicks, etc. Jars and caps should not be cleaned on the spot as these have been precleaned. 



The following sample preparation procedure should be applied prior to shipment. A 

 sample of sufficient live mussels or oysters to provide 300 grams of wet tissue (less tissue wet 

 weight may have to be accepted for less numerous populations or smaller individual organisms) is 

 scrubbed clean with a nylon brush and shucked. The contents are allowed to drain in a metal 

 collander untifno further drops of shell fluids drain off (about 15 min.). The tissue is transferred 

 with a metal spoon and ground in a metal hand-operated meat grinder with a fine (1 mm) screen 

 into a stainless steel bowl. Divide the sample into three aliquots and transfer to three pre-cleaned 

 sampling jars to be frozen. Remove a small quantity (1-2 grams), place it in a scintillation vial of 

 known weight for wet/dry weight determination, and carefully record the weight of vial and tissue. 



If transport of frozen samples is not possible, then the following procedure is 

 recommended. Transfer about 100 grams of the minced tissue into each three precleaned and 

 preweighed sample jars and reweigh and record the weight of wet tissue in each jar. Add about 

 700 grams of sodium sulfate to each jar, reweigh and record the weights. Transfer the wet tissue 

 to a mortar and add 700 grams of sodium sulfate in aliquot, while grinding the tissue with pestle. 

 Care must be taken not to loose sample from mortar. Transfer the sodium sulfate plus tissue to the 

 sample jar. Seal the jars and record details according to instructions. 



As soon as practical, the dry weight of the sample should be determined using supplied 

 portable oven, by drying at 105 degrees centigrade to constant weight with storage in a desiccator 

 when cooling. Record wet and dry weights. 



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