This standard specifies two calculation procedures ("method A" and "method B") for PCB content. The basis for this quantification is taken from the chromatographic results of EN 12766-1:2000 in which all necessary experimental procedures are described for the specific analysis of unused, used and treated (e.g. dechlorinated) petroleum products including synthetic lubricating oils and mixtures of vegetable oils. The method is also applicable to petroleum products and synthetic lubricating oils suitably recovered from other materials, e.g. from waste materials. Both methods have different strengths and weaknesses which are described in the next paragraphs and which must be considered before use in a specific application. Proper application of either method A or method B needs to be carefully considered before use in a specific application.
Using method A, special care needs to be exercised to avoid interferences from non PCB substances which may occur in the chromatogram. Therefore, method A can be used predominantly for the analysis of used and unused insulating oils. It is recommended not to use calculation method A without special precautions for other than above-mentioned products. Calculation method A can produce two alternative sets of results, ("All Probables" and "All Possibles").
Therefore, care needs to be taken in order to interpret these results in the correct manner.
Method B uses as intermediate result the sum of six congeners, which belong to the most abundant in almost all technical PCB materials, thereby minimizing potential interferences from other (coeluting) non PCB substances. To obtain the PCB content, the intermediate sum from six congeners needs to be multiplied by a multiplication factor. Calculation Method B can be used predominantly for the analysis of liquids from used and waste materials of unknown origin and for samples with low PCB contents.