DETERMINATION OF ADDITIVES IN PVC MATERIAL BY UV LASER-ABLATION INDUCTIVELY-COUPLED PLASMA-ATOMIC EMISSION-SPECTROMETRY

UV laser ablation inductively coupled plasma atomic emission spectrome try (LA-ICP-AES) has been applied to the direct determination of addit ives in solid poly(vinyl chloride) materials. A Nd:YAG laser, operatin g at its fourth harmonic (266 nm), was used with a beam masking device , in the most reproducible conditions, to introduce solid particles in to the plasma torch of a simultaneous ICP-AES system. Emphasis was pla ced on both precision and accuracy in the analysis of PVC materials by LA-ICP-AES. A series of six in-house PVC reference materials was prep ared by incorporating several additives in increasing concentrations. Three alternative methods were evaluated to certify the amount of inco rporated elements: ICP-AES with sample dissolution, NAA and XRF. Satis factory results and good agreement were obtained for seven elements (A l, Ca, Cd, Mg, Sb, Sn and Ti) among the ten incorporated. Sample homog eneity appeared to be satisfactory, and calibration graphs obtained by LA-ICP-AES for several elements are presented. Finally, the performan ce of the technique in terms of repeatability (1.6-5%), reproducibilit y (2-5%), and limits of detection was investigated. (C) 1997 Elsevier Science B.V.