Performance of a Dual Sample Introduction System with Conventional Concentric Nebulizers for Simultaneous Determination of Hydride and Non-Hydride Forming Elements by ICP-OES

A dual sample introduction system that combines the benefits of nebulization and vapour generation in a single device is described. It consists of two commercial conventional concentric nebulizers coupled to a modified cyclonic chamber. The effect(s) of the solvent load produced by the amount of liquid carried for the system by the two nebulizer assemblies is investigated. Better sensitivities, similar precision and DL's (with the exception of hydride forming elements) were obtained compared with those obtained with the system working in single mode. Long term stability was less than 7% with the dual mode, being 2% and 6% for the non-hydride and hydride forming elements, respectively, in the single mode operation. DL's obtained are of the same order of magnitude as those reported by several authors, with the exception of Se whose conditions were in compromise with the optimal reached for the rest of the elements. Accuracy of the dual system was proved by analyzing NIST 1648, urban particulate matter, with satisfactory results.