The International Mussel Watch 



d . Detergent. 



e. Fuming sulphuric acid ( d 20°C = 1.84 g ml" 1 ), if required for confirmation. 



f. Nitrosulphuric acid made of concentrated sulphuric acid and sodium nitrate. 



g. Anhydrous sodium sulfate, precombusted at 400°C in muffle furnace. 



h. Alumina 



i. PCB reference solutions - Prepare stock solutions of Aroclor 1242 and Aroclor 1254 by 

 dissolving 100 mg Aroclor in 100 ml iso-octane. Store stock solutions in sealed glass 

 ampoules. 



j. CB isomer reference solutions: DDT reference solutions - Prepare a stock solution of the 

 DDT series (p,p'-DDT, o,p'-DDT, p,p'-DDE, o,p'-DDE, p,p'-DDD) by dissolving 100 mg of 

 each compound in iso-octane. Store stock solution in sealed glass ampoules. 



k. Other reference solutions must be prepared for all other residues to be quantified in these 

 procedures. The suggested list of organochlorine pesticides for International Mussel Watch is 

 as follows: 



In addition to a common set of selected individual chlorobiphenyls - PCB I (IOC-Kiel) and 

 standards for semi-quantitative screening for toxaphene residues should be prepared. 



1. Potassium hydroxide pellets. 



m. 2,5,2',6' tetra-chlorobiphenyl and 1,1 dichloro-2,2-diphenylethylene 



86 



