EVALUATION OF THE PERFORMANCE OF MICROWAVE-INDUCED PLASMA-ATOMIC ABSORPTION SPECTROMETRY (MIP-AAS)

An innovative method of MIP-AAS has been developed. The sample solution was introduced by using an ultrasonic nebulizer. The desolvation was accomplished by a heating tube and a combination of a water-cooled condenser and a concentrated sulfuric acid desiccator. Both an L-shaped and a T-shaped plasma discharge tube were used as the absorption cell in the experiment. The experimental parameters were carefully examined and optimized for the elements studied. Some comparison of properties for these two different absorption tubes was made, and the analytical performance of MIP-AAS was evaluated. The characteristic concentrations obtained in this work were shown to be around ppb under the optimized experimental conditions for 12 elements. Good repeatability and accuracy were achieved. The analytical figures of merit were found to be much better than those obtained by ICP-AAS and previous MIP-AAS experiments and comparable to or even better than the best reported values of flame AAS.