Laser ablation-atomic fluorescence approach for the determination of mercury

A method for the determination of mercury in solid samples using laser abla tion coupled with atomic fluorescence spectroscopy has been developed. An N d-YAG laser was used for ablation and the vaporised and atomised material w as rapidly led to an atomic fluorescence detector, where excitation and emi ssion took place. The experimental approach was applied to the assessment o f different procedures as sensitive as possible for implementing standard a ddition methods. Calibration curves were recorded using the prepared standa rds, which exhibited linear ranges between 0.5-100 mu g/g, with excellent r egression coefficients in all instances (0.9907). The precision, expressed as RSD %, was 3 and 4% for contents of 1 and 30 mu g/g respectively, in the same pellet; and 7 and 12% for the same contents and different type of pel lets. The method has been applied to the determination of mercury in CRM of sewage sediment and a sludge sample with a known amount of mercury determi ned by an interlaboratory study. The results obtained show good agreement w ith those expected.