Nebulisers microconcentric

The on-line interface of flow manifolds to continuous atomic spectrometric detectors for direct analysis of samples in liquid form typically requires a nebuliser and a spray chamber to produce a well-defined reproducible aerosol, whose small droplets are sent to the atomisation/ionisation system. A variety of nebulisers have been described for FAAS or ICP experiments, including conventional cross-flow, microconcentric or Babington-type pneumatic nebulisers, direct injection nebuliser and ultrasonic nebulisers. As expected, limits of detection have been reported to be generally poorer for the FIA mode than for the continuous mode. 

Tangen, A., Trones, R., Greibrokk, T. and Lund, W. (1997) Microconcentric nebuliser for the coupling of micro liquid chromatography and capillary zone electrophoresis with inductively coupled plasma mass spectrometry. J. Anal. At. Spectrom., 12, 667-670. 

Lofthouse, S. D., Greenway, G. M., and Stephen, S. C. (1998). Comparison of inductively coupled plasma mass spectrometry with a microconcentric nebuliser and total reflection X-ray spectrometry for the analysis of small liquid volume samples.J.Anal.At. Spectrom. 13(12), 1333. 

The sample volume available for analysis is directly linked to the analyte concentration (can the sample be diluted and the analyte still be detected ) and mainly results from the sample preparation procedure. For this purpose, a variety of nebulisers with different sample uptake rates is available ranging from some 20 p,L/min (microconcentric nebuliser) to 2 mL/min (ultrasonic nebuliser). For more details on nebulisers see Chapter 5. 

The microconcentric nebuliser (MCN) is another low-flow concentric pneumatic nebuliser designed to analyse low-volume samples. In contrast to the DIN and the HEN, the MCN is capable of nebulising samples containing high concentrations of mineral acids (e.g. hydrofluoric... 

Kim et alP described a sample pretreatment system for online determination of Pu using magnetic sector-ICP-MS with isotope dilution. They used a computer-controlled online sample preparation system (the PrepLab, Thermo Electron Corp., Winsford, UK) with Sr-Spec and TEVA-Spec resin micro-columns for Pu preconcentration. These resins, obtained from Eichrom Industries Inc. (Darien, Illinois, USA), were highly selective for radionuclide elements. To reduce the effect of the U H interference on Pu, a microconcentric nebuliser with integrated desolvation system (the MCN 6000, Cetac, Omaha, Nebraska, USA) was used as the sample introduction method. Using this approach, the authors were able to determine less than 10 pg of Pu in soil samples. 

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