Chromatographic determination of UV absorbers in car paints

Car paints not only must be stable to sunlight effects but also must protec t paint sub-layers. For this purpose, the transparent melaminic/acrylic pai nts of recent formulation contain added stabilisers (UV-As) which are able to absorb UV radiation. The present work presents a chromatographic method that can be easily appli ed in industrial laboratories for the separation and determination of three hydroxybenzotiazoles, commercially known as Tinuvin 900, Tinuvin 328, and Tinuvin 1130, widely used as UV absorbers. The method, that involves the ex traction process from the polymeric matrix and the RP-HPLC determination, i s validated with respect to a lab prepared model paint and applied to comme rcial samples of known and unknown composition.