Note 1 to entry: The general CAS-Number for polychlorinated biphenyls is 1336-36-3. For a comprehensive congener list with CAS-Numbers, see Annex A or Reference [5].

Note 1 to entry: No subsequent additions of internal reference materials are permitted. Surrogate standards reference materials can be added to assess recovery rates only, but these cannot be deemed an internal reference materials, nor can these be used for quantitation.

Note 2 to entry: Mass spectrometry assumes a vast linear range of detector sensitivity, thus a calibration with a single quantity will usually suffice.

Note 3 to entry: In case of major deviations between analytes and reference material concentrations, the quantitation might need to be confirmed by a second analysis (from the beginning) using an adequately adapted sample weight.