The application of ultrasonic nebulization to ICP-AES analysis of metallurgical and geological samples

[摘要] ENGLISH ABSTRACT:The purpose of this project was to investigate the application of ultrasonic nebulization (with and without desolvation) to inductively coupled plasma atomic emission spectroscopy (ICP-AES) for the detection of low concentration elements in metallurgical and geological samples. The investigation included a study on the droplet sizes, the influence of desolvation on the plasma parameters and the determination of the detection limits.Many promising results were obtained in this project. The ultrasonic nebulizer has proved to be a very efficient component in ICP-AES. The results have shown the ultrasonic nebulizer is especially suited for elements at low concentration levels as the superior power of detection produced by the ultrasonic nebulizer cannot be matched by pneumatic nebulizers. It was found that desol vation is not essential for analyses, although the results have shown that even better sensitivity and therefore better powers of detection are obtainable with the use of desolvation. An important and hitherto unknown result of the desolvation investigation is the existence of an optimum desolvation temperature where the analyte emission intensity displays amaximum. A complete Simplex optimization of the whole instrument and procedure was therefore vital for optimum results. A knowledge of the influence of the solvent on the plasma parameters proved to be essential for a better understanding of the applicability of the ultrasonic nebulizer for analyses. However the ultrasonic nebulizer system developed in this project is unfortunately not quite suitable for quick routine analysis due to slow sample changeover, but certain modifications is proposed to improve the speed of analysis.

[发布机构] Stellenbosch University