Spray chamber Scott

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. 

Liver and kidney (Subramanian and Meranger, 1982) - 1 g samples are digested with 8 mL cone. HNO3 + 2 mL cone. HCIO4 in 50 mL Pyrex beakers on a sand bath, taken to near dryness, dissolved in 1 mL cone. HCI, made up to 10 mL with 0.5 M HCI and pumped at 2 to 2.5 mL/min into a cross-flow nebulizer equipped with a Scott spray chamber. Instrumentation ARL model QA-137 ICP-AES spectrometer, argon plasma, 27.12 MHz. A = 231.60 nm, forward power 1600 50 W, observation height 16 mm above the induction coil. Detection limit (blank -1- 2 S.D.) 0.01 mg/L. Correction for Fe and Mg required. 

Scott spray chamber A sealed spray chamber with an inner tube inside a larger tube. The sample aerosol from the nebulizer is first directed into the inner tube. The aerosol then travels the length of the inner tube, where the larger droplets fall out by gravity into a drain tube and the smaller droplets return between the inner and outer tube, where they eventually exit into the sample injector of the plasma torch. 

Concentric glass nebulizer with Scott spray chamber. Ultrasonic nebulizer with desolvation. 

A further study by the Olesik group [138] used an interface with a laminar flow in the direction of the detector. The interface was a stainless-steel tee with the capillary threaded through the colinear ends of the tee. A sheath electrolyte was delivered through the lower arm of the tee with a peristaltic pump. Both a high efficiency nebuliser (HEN) and a concentric glass nebuliser were used in the study the former was used with a conical spray chamber and the latter with a Scott double-pass spray chamber. Increasing the sheath electrolyte flow-rate enabled the laminar flow to be eliminated, therefore improv-... 

An aerosol generated by nebulization is directed through a spray chamber (nebulizer chamber). This is usually made of glass, quartz, or inert polymers (Ryton or several fluorine-based polymers), which prevents large aerosol droplets from reaching the plasma. The classical Scott chamber design has been superseded by the cyclonic chamber, which has a 50% better sensitivity. 

Three different spray chamber designs (Fig. 3.6) are most often used for ICP-MS the Scott [15] (double-barrel) chamber, a conical chamber with an impact bead, and a cyclonic chamber [14,16,17]. The cyclonic spray chamber typically provides a slightly (up to about a factor of 2 or 3) higher analyte transport efficiency as well as somewhat shorter washout times. In some cases the spray chamber is cooled (such as on the HP 4500 ICP-MS double-pass spray chamber, which is cooled to 4°C) to reduce the amount of water vapor that enters the ICP further so that signals from polyatomic ions containing oxygen are reduced. The cooled spray chamber also helps maintain a stable spray chamber temperature. 

Figure 6 Spray chambers (a) Scott, double-pass design, (b) Conical chamber with impact bead, (c) Cyclone spray chamber (top view), (d) Cyclone spray chamber (side view).

Spray chamber Scott-type double-pass... 

The elements Al, Mn, and Sr were determined by means of a Perkin-Elmer Optima 4300DV inductively coupled plasma emission spectrometry (ICP-AES) instrument (axial mode), equipped with an AS-90 Plus autosampler, a cross-flow nebulizer, and a Scott-type spray chamber in Ryton. The instrumental operating parameters are listed in Table 10.1. 

Fosinopril sodium Pd 0.1 pg/g Plasma Quad PQ 11 Turbo plus ICP-MS Jacketed Scott Type Spray Chamber [95]... 

In the cyclonic spray chamber droplets are discriminated according to their size by means of a vortex produced by the tangential flow of the nebulizer. Smaller droplets are transferred with the sample aerosol into the ICP-MS, while the larger droplets collide with the walls and exit by gravity via a drain tube. If compared to the Scott design, the cyclonic spray chamber typically shows higher sensitivity. 

An ICP-Q-MS (Varian 820-MS, Darmstadt, Germany) with a concentric nebulizer (MicroMist) and a double-pass Scott-type spray chamber cooled by a Peltier system was used for analysis of Pd. Table 1 details the ICP-Q-MS operating conditions. Maximal intensity was optimized for In" and minimal values for CeOVCe and Ba QBa. For ID calculations three isotope ratios ( ° Pd/ °" Pd, 105pd/106pd, lOSpjj/lOSpj 2). 

Figure 2.18 (a) Concentric nebulizer mounted on a Scott-type double-pass spray chamber. 

FIGURE 3.10 A Scott double-pass spray chamber with cross-flow nebulizer (copyright 2003-2007, all rights reserved, PerkinEhner Inc.). 

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