Analytical evaluation of a dual micronebulizer sample introduction system for inductively coupled plasma spectrometry

The analytical performance of a dual nebulization system is evaluated for sample nebulization at lower solution uptake rates in inductively coupled plasma optical emission spectrometry (ICP-OES). The system is essentially a modified cyclonic spray chamber that allows the simultaneous operation of two micronebulizers. This work is focused on the optimization and evaluation of the main analytical figures of merit of this sample introduction system. The usefulness of this dual micro-nebulizer in practical ICP-OES studies is demonstrated by using a tandem calibration technique and by operating this system for hydride generation studies. Results showed that this system presents similar figures of merit to a conventional spray chamber but that the non-spectroscopic interferences, usually present at lower solution uptakes rates, can be compensated for by using the tandem calibration technique with this system. Additionally, the two micronebulizers coupled to the modified cyclonic spray chamber can be used for efficient volatile hydride generation from sub-mL amounts of samples. Interference effects by transition metals have been shown to be corrected by the addition of thiourea. The analytical applicability of the dual system was checked by analyzing two standard reference materials: NIST 1577b, Bovine Liver and NIST 1566a Oyster Tissue. The accuracy achieved when using different calibration techniques and hydride generation are within the certified values when applying the significance t-test at the 95% confidence level.