Spectral interferences in inductively coupled plasma

Z. Zhang and X. Ma, Methods for correction of spectral interferences in inductively coupled plasma atomic emission spectrometry, Ciirr. Top. Anal. Chem., 3, 2002, 105-123. 

Tittes W., Jakubowski N., Stuewer D., Toelg G. and Broekaert J. A. C. (1994) Reduction of some selected spectral interferences in inductively coupled plasma mass spectrometry, J Anal At Spectrom 9 1015—1020. 

Van derVelde-Koerts,T, and De Boer,J. L. M. (1994). Minimization of spectral interferences in inductively coupled plasma mass spectrometry by simplex optimization and nitrogen addition to the aerosol carrier for multi-element environmental analysis.. Anal. At. Spectrom. 9(10), 1093. 

Vanhaecke, E, Dams, R., and Vandecasteele, C. (1993). Zone model as an explanation for signal behaviour and non-spectral interferences in inductively coupled plasma mass spectrometry./zl a/. Ai. Spectrom. 8(3), 433-438. 

De Boer, J. L. M. (1997). Possibilities and limitations of spectral fitting to reduce polyatomic ion interferences in inductively coupled plasma quadrupole mass spectrometry in the mass range 51-88. Spectrochim. Acta, Part B 52(3), 389. 

In inductively coupled plasma-mass spectrometry, isobaric interference occurs between species with the same mass and charge. Interference can be eliminated if the mass spectral resolution is sufficiently great or by dissociating an interfering polyatomic species with a collision cell. When laser ablation is used to sample a solid, matrix-matched standards are often necessary for quantitative analysis. 

Mass Resolution Required to Resolve Common Spectral Interferences Encountered in Inductively Coupled Plasma Mass Spectrometry... 

MASS RESOLUTION REQUIRED TO RESOLVE COMMON SPECTRAL INTERFERENCES ENCOUNTERED IN INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY... 

The table below lists some common spectral interferences that are encountered in inductively coupled plasma mass spectrometry (ICP-MS), as well as the resolution that is necessary to analyze them.1 The resolution is presented as a dimensionless ratio. As an example, the relative molecular mass (RMM) of the polyatomic ion 15N160+would be 15.000108 + 15.994915 = 30.995023. This would interfere with 31P at a mass of 30.973762. The required resolution would be RMM/8RMM, or 30.973762/0.021261 = 1457. One should bear in mind that as resolution increases, the sensitivity decreases with subsequent effects on the price of the instrument. Note that small differences exist in the published exact masses of isotopes, but for the calculation of the required resolution, these differences are trivial. Moreover, recent instrumentation has provided rapid, high-resolution mass spectra with an uncertainty of less than 0.01%. 

Goossens, J., Moens, L., and Dams, R. (1994). A mathematical correction method for spectral interferences on selenium in inductively coupled plasma mass spectrometry. Talanta 41(2), 187. 

Van Veen, E. H., Bosch, S., and De Loos-Vohebregt, M.T. C. (1994). Spectral interpretation and interference correction in inductively coupled plasma mass spectrometry. Spectrochim. Ada. Part B 49(12/714), 1347. 

Bjorn, E. and Freeh, W. (2001) Non-spectral interference effects in inductively coupled plasma mass spectrometry using direct injection high efficiency and microconcentric nebulization. J. Anal. At. Spectrom., 16, 4-11. 

At present, inductively coupled plasma mass spectrometry provides a unique, powerful alternative for the determination of rare earths in natural samples [638,639]. Nevertheless, its application to the determination of rare earths at ultratrace concentration level in seawater is limited, because highly saline samples can cause both spectral interferences and matrix effects [640]. Therefore, a separation of the matrix components and preconcentration of the analytes are prerequisites. To achieve this goal, many preconcentration techniques have been used, including coprecipitation with... 

Kola H, Peramaki P, Valimaki I. Correction of spectral interferences of calcium in sulfur determination by inductively coupled plasma optical emission spectroscopy using multiple hnear regression. J. Anal. At. Spectrom. 2002 17 104-108. 

Milgram, K. E. Abatement of spectral interferences in elemental mass spectrometry design and construction of inductively coupled plasma ion sources for Fourier Transform ion cyclotron resonance instrumentation, Ph. D. Thesis, University of Florida, 1997, Diss. Abstr. Int., B 1998, 59(2), 639. 

Inductively Coupled Plasma-Mass Spectrometry ICP-MS has been accepted as a powerful technique for elemental and isotopic analysis [21D25]. It is characterized by a linear dynamic range of Eve to six orders of magnitude, rapid multielemental analysis, comparative freedom from spectral interferences, and LoDs in the range of 10D100 pg mL-1 for most elements. This makes it ideal for the multielemental analysis of food samples on a routine basis. 

I. Rodushkin, T. Ruth, D. Klockare, Non-spectral interferences caused by a saline water matrix in Q and high resolution inductively coupled plasma mass spectrometry, J. Anal. Atom. Spectrom., 13 (1998), 159-166. 

Machat, J., Otruba, V., Kanicky, V. Spectral and non-spectral interferences in the determination of selenium by inductively coupled plasma atomic emission spectrometry. J. Anal. At. Spectrom. 17, 1096-1102 (2002)... 

Inductively coupled plasma Fourier transform (ICP-FT) can be useful for correcting unexpected spectral interference. However, such a technique has limited applications and development is only in its infancy. 

Knowledge of the atomic spectra is also very important so as to be able to select interference-free analysis lines for a given element in a well-defined matrix at a certain concentration level. To do this, wavelength atlases or spectral cards for the different sources can be used, as they have been published for arcs and sparks, glow discharges and inductively coupled plasma atomic emission spectrometry (see earlier). In the case of ICP-OES, for example, an atlas with spectral scans around a large number of prominent analytical lines [329] is available, as well as tables with normalized intensities and critical concentrations for atomic emission spectrometers with different spectral bandwidths for a large number of these measured ICP line intensities, and also for intensities calculated from arc and spark tables [334]. The problem of the selection of interference-free lines in any case is much more complex than in AAS or AFS work. 

Inductively coupled plasma-atomic emission spectrometry, an atlas of spectral information. The latter is a most useful handbook by pioneers in plasma spectrochemistry, on specifically ICP-AES, beginning with a background to the information and containing interesting wavelength scans and extensive tabulations of lines and spectral coincidence profiles (spectral interferences). 

Concentration of the elements Mn, Fe, Cr, Ni, Co, As, Cd, Pb, Zn and Cu in water and plant samples were measured by inductively coupled plasma mass spectrometry (ICP-MS) (ELAN 5000, Perkin-Elmer). The instrument was calibrated by external standards of multi-element solutions for a range of 1-10 p-g/kg for water samples and 0.5-20 (xg/kg for plant material. Digested plant samples were diluted accordingly. Matrix effects and spectral interference were compensated by addition of internal standards ( Rh and Th). 

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