Plasma spray atomization

Carayon, M.T. and Lacout, J.L. (2003) Study of the Ca/P atomic ratio of the amorphous phase in plasma-sprayed hydroxyapatite coatings. J. Solid State Chem., 172, 339-350. 

The most recent significant advance in plant hormone analysis has been the use of combined HPLC-MS for the analysis of GA conjugates, lAA conjugates and cytokinins. A number of interfaces have been developed for HPLC-MS, including thermospray, atmospheric pressure chemical ionisation, electrospray, particle beam, continuous flow fast atom bombardment (FAB) and frit-FAB (see reference [94]). GA standards have been analysed by HPLC-MS with a thermospray interface [95], an atmospheric pressure chemical ionisation interface has been used with GA conjugates [96] and cytokinins [97] while ion spray and plasma spray have been used to analyse ABA and its metabolites [98]. There are, however, many more reports on the use of frit-FAB HPLC-MS for the analysis of not only standards, but also endogenous hormones and their isotopically-labelled metabolites [18-23,99-101]. 

IPS. Inert plasma spraying (q.v.). Iridizing. The formation of a film of metal oxide on the surface of a ceramic, particularly of glass. The surface to be treated is heated and then exposed to the vapour, or to atomized spray, of a metal salt. Such surface films may be applied as decoration or to provide a surface that is electrically conducting, e.g. for anti-frosting windscreens. 

The objective is to deposit a ceramic layer on a support (metal, ceramic, organic) to obtain surface properties different from the massive material. The applications of these coated materials are numerous (tribology, heat insulation, corrosion resistance, electronics, optics, optoelectronic, biomedical, etc.). The thickness of the layers can vary from a few atomic layers for techniques of vacuum deposition (they are called thin layers) to a few milUmeters in the case of plasma spraying. 

The stoichiometric HAP, characterized by an atomic ratio Ca/P = 1.67 and a hexagonal structure, is the nearest relative of biologic apatite ciystals. Moreover, the HAP is the least soluble and the least resorbable calciirm phosphate. When an HAP ceramic is implanted in a bone site, the bone tissue formation is observed on its contact (osteoconduction) (see Figure 12.1). Besides, in certain conditions, calcium phosphate ceramics can induce the formation of bone tissue in ectopic sites. HAP implants appear in the form of dense ceramics or with variable porosity or again, in the case of prostheses, as thin coatings deposited by plasma sprayed on a metal. 

DLR is developing DBLs of perovskite materials, such as doped LaCrOs-type and LaMnOs-type, by atmospheric plasma spray (APS), vacuum plasma spray (VPS), or pulse laser deposition (PLD) [16-21]. Using doped LaCrOs layer deposited by VPS on FSS alloy [15], they showed that after 230 h of cell operation, both Ni in the substrate and Fe in the anode replace less than 0.1 % of the primary metal atoms. This is about hundred times less than the 17 % of Ni atoms in grain substituted by Fe and Cr in an anode of a cell prepared without DBL. 

For inductively coupled plasma atomic emission spectroscopy (ICP-AES) the sample is normally in solution but may be a fine particulate solid or even a gas. If it is a solution, this is nebulized, resulting in a fine spray or aerosol, in flowing argon gas. The aerosol is introduced into a plasma torch, illustrated in Figure 3.21. 

Fast atom bombardment (FAB) Plasma desorption (PD) Liquid secondary-ion mass spectrometry (LSIMS) Thermospray (TSP)/plasmaspray (PSP) Electrohydrodynamic ionisation (EHI) Multiphoton ionisation (MPI) Atmospheric pressure chemical ionisation (APCI) Electrospray ionisation (ESI) Ion spray (ISP) Matrix-assisted laser desorption/ionisation (MALDI) Atmospheric pressure photoionisation (APPI) Triple quadrupole (QQQ) Four sector (EBEB) Hybrid (EBQQ) Hybrid (EB-ToF, Q-ToF) Tandem ToF-ToF Photomultiplier... 

Atmospheric pressure spray with electron impact ionisation Atomic plasma emission spectrometry... 

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