Pneumatic nebulizers Meinhard nebulizer

Sample introduction has been acconplished using both conventional, pneumatic nebulizers (Meinhard type) and spray chambers as well as via ultrasonic nebulization coupled with desolvation (Cetac, Inc. model U-5000). The ICP sources and vacuum interfaces we have incorporated into our PSIT and PSQ instruments were manufactured by VG Elemental (now Thermo Electron Corp). ICP operating conditions were 1250 W forward power, sampling distance 10 mm, argon flow rates of 0.9, 1.2 and 13 L/min respectively for the nebulizer, auxiliary and cool gas channels. The ion traps used were ITMS or LCQ instruments manufactured by the Einnigan Corporation (San Jose, CA now Thermo Electron Corp). The ICPs were coupled to the ion traps using custom built vacuum chambers and ion optical components as well as portions of the original VG Elemental ICP-MS vacuum interface. These and other experimental details have been published elsewhere. 

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... 

In ICP-MS mostly liquids are analyzed. The aqueous solution is nebulized using an effective pneumatic nebulizer (e.g., Meinhard or MicroMist nebulizer with cyclonic spray chamber, ultrasonic nebulizer (USN), microconcentric nebulizer with desolvator (e.g., Aridus or APEX), the latter for the introduction of small volumes of solution)3 as described in Section 5.1.6. 

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. 

For many years pneumatic nebulizers of the V-groove, Meinhard and cross-flow type have been the most widely used sample insertion devices for aerosol generation. The interaction geometry between the gas and liquid sample streams allows pneumatic nebulizers to be classified into two major groups, namely (a) pneumatic concentric nebulizers, which involve concentric interaction and (b) cross-flow nebulizers, which involve perpendicular interaction between the liquid and gas streams. Pneumatic nebulizers are well established and widely used on account of their simplicity, robustness, ease of use and low cost however, they provide low transport efficiency and tend to be clogged by high salt-content solutions [4]. 

Honey, Bread BCR CRM Cu Fe Mn Zn MicrowaveDigestion in closed vessel with HNO3/H2O2 [WDM] JY 70 VHR ICPAESr with Meinhard pneumatic nebulizer [ICP-AES] [WDM-ICP-AES] Carol et al. (1999)... 

The sample introduction from an LC column to ICP-MS is performed by a nebulizer. The usual nebulizers are pneumatic nebulizers, such as Meinhard, crossflow, or microconcentric nebulizers (MCNs). Additionally, there is the ultrasonic nebulizer (USN), the direct-injection nebulizer (DIN), and the hydraulic high-pressure nebulizer (HHPN). The nebuli-zation efficiency depends on nebulizer type and is typically low for Meinhard and crossflow nebulizers (only around 1—5 %, [23]), whereas it is high for the DIN and USN. 

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