Metals Analysis in the Plastics Additives Industry

A discussion of the methods used for the atomic spectroscopic determination of barium, cadmium, zinc, and phosphorus in vinyl stabilizers is presented. Comparison with aqueous measurements shows that the determination in organic media by inductively-coupled plasma atomic emission spectroscopy (ICP-AES) is the most desirable analytical approach for these samples. Evaluation of a variety of potential materials shows well-characterized in-house products to be viable, and even preferred, reference materials for the verification of the accuracy of these analyses. Alternative analytical techniques, interlaboratory comparisons, and the use of control charts are also discussed.