Development and characterization of a Flow Focusing multi nebulization system for sample introduction in ICP-based spectrometric techniques

Abstract

In this work, a new multiple nebulizer for liquid sample introduction in ICP-based spectrometers was developed and characterized on ICP-AES. The association of the Flow Focusing multiple nebulizer (FFMN) and a dedicated spray chamber was called Flow Focusing multi nebulization system (FFMNS). The nebulizer incorporates four nebulization nozzles with independent liquid feeding and a common gas inlet. Four different spray chambers were constructed and evaluated and the geometry of the best performing one was optimized. The FFNMS was characterized at 0.6–0.9 L min⁻¹ nebulizing gas flow and 0.04–0.6 mL min⁻¹ total liquid sample flow. Drop size and velocity distributions of primary and tertiary aerosols were studied together with total solvent and analyte transport rates. The system was characterized on ICP-AES in both axial and radial view modes and compared to a standard sample introduction system consisting in a concentric nebulizer and a cyclonyc spray chamber using model solutions and certified reference materials (CRM). In terms of sensitivity and LOD, the FFMNS showed a similar behavior to the reference system at half of the liquid sample uptake (0.5 mL min⁻¹ for FFMNS vs. 1 mL min⁻¹ for the standard system). The CRM (hard drinking water) analysis recovery results are ranged between 89%–106% for FFMNS, and between 78%–102% for the reference system. Finally, the FFMNS was applied to an “in chamber” standard addition analysis of synthetic samples and CRM (estuarine water). The results of the CRM analysis showed better recoveries with respect to the external calibration for Cd, Mn and Ni, and similar results for Cu and Pb.