A RAPID, NONDESTRUCTIVE, IN-SITU ANALYSIS OF PLASTICS FOR HEAVY METALS WITH PORTABLE X-RAY FLUORESCENCE ANALYZER

摘要

Recently introduced regulations, such as European Community "Packaging Directive" - EC-Directive 94/62/EEC (1), impose the maximum limit on total amount of metals such as Cd, Cr, Hg and Pb in plastic packaging materials to less than 100 mg/kg. Another EU Directive, 91/338/EC (2), sets the maximum allowable concentration of cadmium in plastics used for consumer goods at 100 mg/kg. In the US, the "Proposition 65" introduced in California banned cadmium from use. Effective enforcement of these regulations creates the need for analytical methods capable of rapid, accurate, nondestructive in-situ analysis of plastics. An X-ray Fluorescence Analysis (XRF for short) is very well suited for this task. In this paper we report on successful application of a small, portable X-ray fluorescence analyzer in analysis of plastic for metals. The analyzer can quantify heavy elements such as lead and cadmium in plastics down to 10 and 25 mg/kg, respectively, at a 120 sec. measurement time per sample.