ISO DIS 787-28

Description / Abstract: This part of ISO 787 specifies a method for determining the total contents of polychlorinated biphenyls (PCBs), checking for all 209 possible congeners in pigment materials.

NOTE 1 Occurrence and formation principles can be referred to Lit,[5] pp. 179, 277 with 416 and 426/7[6] and in a more dedicated publication[8].

NOTE 2 A number of methods to quantify PCBs in “environmental samples” or oil residues prove inadequate for pigments due to being merely extractive on the particle surface without taking into account occlusions of contaminants in the crystal lattice of pigments[1-3].

The use of such solid surface extraction methods risks underestimating the actual content by orders of magnitude. Such errors are often further enhanced when the PCBs quantitation is carried out by using external or internal reference materials which do not undergo the same losses as the analytes that are occluded in the crystal lattice of the pigment.

Furthermore, Aroclor^® or Clophen^® mixes may not be used as reference materials as most PCB congeners therein are not related to pigment chemistry[5,7,8].

Lower quantitation limit: 1 mg/kg

NOTE 3 A homologue group result below 1 mg/kg will remain qualitative only, since the internal RSD will approach 100 %.

Working range: 1 mg/kg to 150 mg/kg

NOTE 4 In case of higher PCB content a reanalysis has to be done with a correspondingly lower sample weight.