Plasma mixed gas

Jackson SE, Gunther D (2003) The nature and sources of laser induced isotopic fractionation in laser ablation-multicollector-inductively coupled plasma-mass spectrometry. J Anal At Spectrom 18 205-212 Jiang S-J, Houk RS, Stevens MA (1988) Alleviation of overlap interferences for determination of potassium isotope ratios by Inductively-Coupled Plasma Mass Spectrometry. Anal Chem 60 1217-1220 Lam JWH, Horlick G (1990) A comparison of argon and mixed gas plasmas for inductively coupled plasma-mass spectrometry. Spectrochim Acta Part B 45 1313-1325 Langmuir I, Kingdon KH(1925) Thermionic effects caused by vapours of alkali metals. Phil Trans R Soc A107 61-79... 

Compared with the ICP, other atomic spectrometric detectors are not widely coupled to HPLC. Several interfaces have been described for AAS detector. Methods include a rotating platinum spiral collection system (Ebdon et al., 1987) and a flow injection thermospray sample introduction system (Robinson and Choi, 1987). Post-column hydride generation is also popular with AAS detection as will be described later. Pedersen and Larsen (1997) used an anion-exchange column to separate selenomethionine, selenocysteine, selenite and selenate with both FAAS and ICP-MS. The detection limits for the FAAS system were lmg H1 compared with 1 fig l-1 for ICP-MS. HPLC-MIP systems have been described to an even lesser extent. These either use elaborate interfaces to overcome the problems of quenching the low-power plasma (Zhang and Carnahan, 1989) or use a modified argon/oxygen mixed gas plasma (Kollotzek et al., 1984). 

Mixed Gas Plasmas. Water loading can be reduced by a desolvation system (condenser or membrane separator) only if the vast majority of the water can be removed. One way to eliminate the introduction of water into the plasma during measurement of the analyte signals is with electrothermal vaporization, laser ablation, or other direct solid sampling techniques. Mixed gas plasmas,... 

Phosgene has been employed in the modification of the surfaces of cellulose-acetate membranes used for water desalination and waste water treatment [1450]. Similarly, phosgene has been used to surface-modify porous diaphragms for electrolytic cells [324]. Aluminium and aluminium-based alloys can be etched at a high rate when COClj is used in a mixed gas plasma [1004], as can semiconductors (see Section 9.12). 

Crowe,S.A.,Fryer,B.J.,Samson,I.M.,Gagnon,J.E.(2003) Precise isotope ratio determination of common Pb nsing quadrupole LA-ICP-MS with optimized laser sampling conditions and a robust mixed-gas plasma. Journal of Analytical Atomic Spectrometry, 18,1331-1338. 

A comparison of argon and mixed gas plasmas for ICP MS, Spectrochim Acta, Part B 45 1313-1325. 

Mixed-gas plasmas Reduced spectroscopic interferences Reduced matrix effects Higher incidence of torch melting Analysis of fuel oil, vegetable oil, sea water, urine, slurries... 

Beauchemin, D., and Craig, J. M. (1991). Investigations on mixed-gas plasmas produced by adding nitrogen to the plasma gas in ICP-MS. Spectrochim.Acta, Part B 46(5), 603. 

Bloxham, M.J., Worsfold, P. J., and Hill, S.J. (1994). Matrix suppression in sea-water analysis using inductively coupled plasma mass spectrometry with mixed gas plasmas. Anal. Proc. 31(3), 95. 

Morse, C. E. (1994). The use of mixed gas plasma for trace elemental analysis of metal alloys using inductively coupled plasma mass spectrometry. Unpublished M.S.Thesis, MarshaU University, Huntington, WV. 

Persaud,A.T.,Beauchemin,D.,Jamieson,H.E.,and McLean, R.J. (1999). Partial leaching as an aid to slurry nebulization for the analysis of soils by ICP-MS with flow injection and mixed-gas plasmas. Can.J. Chem. 77(4), 409. 

The argon ICP is by far the most common type of plasma to be coupled with mass spectrometric detection. As discussed above, alternative gas and mixed gas plasmas have been used, but several other types of plasma have also been employed one such plasma is the microwave-induced plasma (MIP). The MIP usually utilises helium and is therefore very highly ionising. It suffers far fewer interference problems than argon-based plasmas, although traditionally it has had the reputation of not being a very robust plasma, i.e. it is easily extinguished by the... 

Lam, J. W. H. and Horlick, G. (1990) A comparison of argon and mixed gas plasmas for inductively coupled plasma-mass spectrometry. Spectrochim. Acta B, 45,1313. 

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