Analysis of paper by laser-induced plasma spectroscopy

Material distributions in paper and paper coatings are important factors wh ich determine the characteristics and quality of paper. We have used laser- induced plasma spectroscopy (LIPS) to determine various properties of coate d and uncoated papers. Depth profiles of double coated papers were determin ed. Microscopic variations of pigments in a double-coated paper were analyz ed. It was observed, that the two coating layers can be distinguished, if t hey differ enough in composition. Filler distributions of uncoated copier p apers were determined. The surface of the paper was studied for five sample s containing different amounts of binder in the coating. Lateral contaminat ion in paper analysis i.e. splash over effect of ablation was studied by va rying the sampling distance and number of laser pulses used for ablation. I nfluence of splash over effect on lateral analysis is briefly discussed. (C ) 2001 Published by Elsevier Science B.V.