ICP source

The etch experiments were performed using a commercial ICP etcher equipped with an ICP source and a load lock. The substrate susceptor was cooled by He through a chilled fluid. The coil, which was connected to a 13.56 MHz RF power supply, was located on the lid of a ceramic chamber to generate a high density plasma. A bias voltage induced by RF power at... 

Fig. 3. Forward (top) and reverse (bottom) voltages of InGaN/GaN MQW LED with and without annealing after etching as a function of ICP source power.

Solid sampling techniques for ICP emission spectrometry need to be calibrated by very carefully characterized RMs or CRMs, if available. For example, the determination of Pb by vaporization of very small sample amounts into an ICP source was shown to be independent from matrix effects by using different CRMs for cahbra-tion (Ohls 1989). 

For both TIMS and MC-ICPMS, improvements in sources are likely to play a major role in enhancing measurement sensitivity. This includes further development of cavity sources for TIMS and newer ICP sources and nebulizers with reduced isobaric... 

It can be seen from the above that the sample stream emerging from the plasma will be rich in free ions and atoms of the elements from the sample. Thus, the ICP could provide an attractive source for analytical methods other than those based upon straightforward emission. Instruments using the ICP source as a basis for atomic fluorescence have been developed. 

More importantly, however, the ICP source has been applied to provide a source of ions for mass spectrometry ( vide infra). 

There are several sample introduction methods that are used in conjunction with ICP, including nebulization, electrothermal evaporation, gas chromatography, hydride generation, and laser ablation [30]. Laser ablation combined with ICP (LA-ICP) is useful for analysis of solids. In such a source the sample is positioned in a chamber prior to the ICP source, the ablation cell. Argon gas at atmosperic pressure flows through the cell towards the ICP source. The sample is irradiated by a laser beam and... 

The inductively coupled plasma (ICP) technique described in Chapter 9 (Section 9.5) has been coupled with mass spectrometry. The ICP source provides the mass spectrometer with a source of charged monatomic ions such that the electron beam is not needed. The exhaust of the ICP source is fed into the mass spectrometer for analysis by the mass analyzer portion of the mass spectrometer (Figure 10.20). 

An atomizer is a device that forms atoms from ions. Examples include flames, a graphite furnace, an ICP source, vapor generators, etc. 

Standard bracketing is not applicable to TIMS measurements since each sample is on a different filament, which is successively positioned by a rotating turret the mass bias depends on the temperature of the sample film loaded on the filament, as well as on its structure and composition. The run conditions for each sample are therefore variable from one sample to the next and the mass bias cannot be accurately controlled. Electron impact and ICP sources. 

Mass spectrometry is also used for nanoparticles investigations. Two ionization techniques often used with liquid and solid biological samples include electrospray ionization (ESI) and matrix-assisted laser desorption/ioiuzation (MALDI). Inductively coupled plasma (ICP) sources are mainly used for metal analysis. In general,... 

Kleinmann and Svoboda [42] reported direct vaporization of samples into a low-power ICP source from a graphite disc support mounted directly within the body of the plasma torch. Nixon et al. [43] described the use of a tantalum filament electrothermal... 

Among the plasma sources that have been used for analytical measurements include the inductively coupled argon plasma (ICP), direct current argon plasma (DCP) and microwave induced heUum plasma (MIP). The instrumentation and I rformance of the more popular ICP source have been discussed by Barnes More rwently, Thompson and Walsh have published a book dealing with the practical aspects of ICP. 

Gray, A. L. The potential of ICP source mass spectrometry in Instrumentelle Multi-elementanalyse (ed.) Sansoni, B., Weinheim, VCH 1985... 

Furthermore, excited metastable species such as Ar11 ICP source due to ... 

Amselfelder red wine from Kosovo has been investigated with respect to uranium and plutonium content using ICP-SFMS (Element). The microconcentric nebulizer Aridus (Cetac Technologies) was applied for solution introduction into the ICP source. In different red wine samples, uranium with a natural isotopic composition was found at a concentration of 0.145 0.011 Jigl-1, which corresponds to the normal uranium background concentration. Plutonium was not detected at a detection limit of 10-5p,gl-1.36... 

Polychromators for use in Emission Spectrometry with ICP Sources , Anal. Proc., 1986, 23, 109. 

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