Appendix B: Analytical Methods 



Appendix B 

 Central Laboratory Analytical Methods 



No analytical chemistry standard methods exist for the analysis of complex mixtures of 

 organic contaminants in environmental matrices. The goal of standardized analytical results that 

 can be compared between laboratories (or from day-to-day in a single laboratory) is currently being 

 met by performance-based analysis, where accepted QA/QC practices are incorporated into the 

 standard operating procedures of each laboratory. Several methods and variations of these 

 methods have been published in the scientific literature (see reference list with this appendix). 

 These may be used for analyses of chlorinated hydrocarbon pesticides and PCBs; especially for the 

 extraction and initial separations of the classes of analytes of interest. The methods described in 

 any of these reports may be used 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 final method selection by each 

 laboratory. 



The two IMW Analytical Centers used analytical methods and QA/QC practices that they 

 have developed over time to meet their own needs. While basically similar in design, these two 

 methods differ in detail and are summarized here, and in Figure B-l. The method described in the 

 EVTW Manual is an older version, similar to these methods, and is also included for comparison. 

 References which give details of these methods are listed in the reference list at the end of this 

 Appendix. 



Texas A&M GERG 



Methods used by the NOAA Status and Trends Program are modifications to the 

 procedures developed by MacLeod et al (1985) and more recently published in NOAA (1993). 

 Wet tissue is extracted with methylene chloride and combined extracts are chromatographed on 

 silica gel and alumina. The chlorinated hydrocarbon eluant from column chromatography is further 

 seperated by HPLC using a Sephadex LH-20 column. Capillary gas chromatography with electron 

 capture detection is used to seperate and quantify chlorinated hydrocarbons in the mixture. 

 Individual laboratories participating in the NOAA Status and Trends Program have modified this 

 basic procedure. 



IAEA Marine Environment Lab 



Mel uses the analytical methods described in UNEP (1991), extracting organic 

 matter with hexane in a Soxhlet apparatus, concentrating the extract by Kuderna-Danish 

 concentrator, and purifying the extract on Florisil. Recovery standards are routinely added to the 

 extraction step. Organochlorine compounds are found in two elution fractions from the Florisil 



Bl 



