The International Mussel Watch 



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Several methods and variations of these methods have been published in the scientific 

 literature. These may be used for analyses of chlorinated hydrocarbon pesticides and PCB's; 

 especially for the extraction and initial separations of the classes of analytes of interest. The 

 methods described in this Manual are intended as guides for analysts in laboratories in participating 

 countries. Local circumstances including available equipment, chemicals, and solvents, and 

 analytical requirements for other programs in a given laboratory will govern methods used by each 

 laboratory. 



Ultimately, when a full scale, more routine monitoring program is in place, there should be 

 agreement on a few common methods of analyses which have been carefully evaluated as giving 

 comparable results via a rigorous quality control and quality assurance program. Until that time, a 

 program of inter-laboratory comparison exercises is necessary in order to compare data generated 

 by participating laboratories (UNEP 1990). 



The methods set forth in this manual, or equivalent methods, will be used by the central 

 laboratories during the Initial Implementation Phase for the analysis of chlorinated pesticides and 

 specific PCB congeners. There is ajarge scientific literature on the analysis of pesticides and we 

 refer participating scientists to that body of knowledge. Greater detail on the analysis of specific 

 PCB congeners is provided here because this information is comparatively new. 



Regional scientists who retain field-collected samples for analysis during the Initial 

 Implementation Phase will be provided with several Standard Reference Materials (SRMs) and 

 with a freeze-dried tissue homogenate for use in an inter- laboratory comparison exercise. 



Notes: 



/ . Preservation of Total Lipids 



The preservation of total lipids in samples is very important because all data for chlorinated 

 pesticide concentration need to be reported on a lipid normalized basis as well as wet weight and 

 dry weight basis to facilitate comparisons of temporal and spatial trends, especially when 

 comparing data for different bivalve species. The efficacy of lipid concentrations was more of a 

 concern than the preservation of chlorinated pesticides in non-frozen samples because of the 

 inherent lability of several lipid classes compared to chlorinated pesticides. 



Data clearly illustrate that total extractable lipid amounts are not changed appreciably by 

 storage at room temperatures between 22 to 29°C over three months in sealed glass jars with either 

 1:7 (weight/weight) wet tissue homogenate anhydrous sodium sulfate: or 1:3:8 wet tissue 



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