Nebulizer Meinhard

Q. If you wished to nebulize sea-water with a Meinhard nebulizer, what would you have to do first, bearing in mind that sea-water contains 3.5% NaCl ... 

From the sample solution to be analyzed, small droplets are formed by the nebulization of the solution using an appropriate concentric or cross-flow pneumatic nebulizer/spray chamber system. Quite different solution introduction systems have been created for the appropriate generation of an aerosol from a liquid sample and for separation of large size droplets. Such an arrangement provides an efficiency of the analyte introduction in the plasma of 1-3 % only.6 The rest (97 % to 99%) goes down in the drain.7 Beside the conventional Meinhard nebulizer, together with cooled or non-cooled Scott spray chamber or conical spray chamber, several types of micronebulizers together with cyclonic spray chambers are employed for routine measurements in ICP-MS laboratories. The solvent evaporated from each droplet forms a particle which is vaporized into atoms and molecules... 

To quantify the trace elements of interest plasma-based techniques were used, namely (i) ICP-AES using an Optima 3100 instrument (Perkin-Elmer, Norwalk, CT, USA) equipped with a cross-flow nebulizer and a Ryton Scott spray chamber (ii) Dynamic Reaction Cell (DRC) Q-ICP-MS using an Elan 6100 spectrometer (PerkinElmer, Norwalk, CT, USA) equipped with a quartz cross-flow Meinhard nebulizer and a cyclonic spray chamber (iii) SF-ICP-MS using an Elementl (ThermoElectron, Bremen, Germany) with a pneumatic nebulizer and a Ryton Scott spray chamber. 

ICP-MS is a multi-element technique suitable for the analysis of liquid samples, which provides higher selectivity and detection power and LoDs lower than other multi-element techniques, such as ICP-AES. These characteristics make ICP-MS an excellent tool for the detailed characterization of the elemental composition of beverages. In this context, ICP-MS was the technique selected for the determination of 31 trace elements in wine at concentrations ranging from 0.1 to 0.5 ng ml-1 [82]. Samples were diluted 1 + 1 and it was investigated whether a matrix effect derived from the presence of ethanol could be overcome by using a microconcentric nebulizer with membrane desolvation. The authors compared their results with those obtained using a conventional Meinhard nebulizer and concluded that the matrix effect observed could only be minimized by using an internal standard with the Meinhard nebulizer, but not with the other one. 

Figure 28-9 The Meinhard nebulizer. The nebulizing gas flows through an opening that surrounds the capillary concentrically. This causes a reduced pressure at the tip and aspiration of the sample. The high-velocity gas at the tip breaks up the solution into a mist or spray of various-sized droplets. (Courtesy of J. Meinhard Associates, Inc.)...

Fig. 13. Noise power spectra in ICP-MS for ArO+ (56 dalton). Meinhard nebulizer, power 1350 W, outer gas 14 L/min, intermediate gas 1.4 L/min, nebulizer gas 1.0 L/min, sample uptake rate 1.05 mL/min, doubly distilled water. (Reprinted with permission from Ref. [41].)...

AAFCO feed check samples Ca Cu Fe Mg Mn P KZn Digest with HNO3, [WDC] Determine with ICPMSr with Meinhard nebulizer [ICPMS] [WDC-ICP- MS] McGuire and Hite (1998)... 

Tab. 4. Influence of cooling of the spray chamber on the stability of ICP-MS (30 min short-term stability) with a Meinhard nebulizer and an aqueous standard solution analyte concentration ...

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