EVISA Print | Glossary on | Contact EVISA | Sitemap | Home   
 Advanced search
The establishment of EVISA is funded by the EU through the Fifth Framework Programme (G7RT- CT- 2002- 05112).

Supporters of EVISA includes:

ICP-OES sensitivity for silicon depends on silicon-species


The inductively coupled plasma (ICP) is known as a very robust excitation and  ionization source for ICP-OES and ICP-MS. One of its often praised features is the absence of any important influence of the analyte species on its response. In general, this allows the use of a single element species as a calibrant for standardization of the element response of the system. This is especially important for quantification in speciation analysis, where even the determination  of unknown element species is targeted.

Photo: Optical viewing zones within an ICP

The new study:
Researchers from Spain and France investigated the response of different ICP-OES systems with axial and radial viewing optics and also different sample introduction systems for different silicon compounds. To mimic the situation of petrochemical analysis, solutions containing sixteen different silicon organic compounds with the same silicon concentration were prepared in xylene. The studied compounds were: six siloxanes, nine silanes and a silicate. Their boiling points ranged from 101 °C (hexamethyldisiloxane) to 310 °C (2,3,4-(epoxycyclohexyl)ethyltrimetoxysilane).

The results they obtained with different sample introduction systems indicated that the ICP-OES signal depended strongly on the silicon compound and the sample introduction system in use. Thus, for a commonly used sample introduction system consisting of  a cross-flow pneumatic nebulizer coupled to a Ryton double pass spray chamber, the signal varied by a factor of up to 17, depending on the compound. For most studied cases, some siloxanes yielded higher emission intensities than silanes.

Both aerosol and plasma diagnostic experiments were carried out to elucidate the origin of such behavior. The results indicated that the different response is at least in part a result of differences in the aerosol transport efficiency of the Si-species. The distribution of the analyte species over the gaseous, fine aerosol and coarse aerosol droplets depends on the analyte species. Therefore, spraychambers with a lower transport efficiency such as the double-pass chamber showed more pronounced effects than total consumption systems. The importance of this study also lies in the fact that matrix effects caused on silicon cannot be corrected for by means of internal standardization or standards additions when analyzing petroleum samples.

Since the observed effects could be traced back to the sample introduction system that is shared between ICP-OES and ICP-MS, it is expected that similar effects can be observed also in ICP-MS.
Michael Sperling

Original study:

Raquel Sánchez, José-Luis Todolí, Charles-Philippe Lienemann,  Jean-Michel Mermet, Effect of the silicon chemical form on the emission intensity in inductively coupled plasma atomic emission spectrometry for xylene matrices, J. Anal. At. Spectrom., 24/4 (2009) 391-401. doi: 10.1039/b806594m

Related studies:

Raquel Sánchez, José Luis Todolí, Charles-Philippe Lienemann, Jean-Michel
Mermet, Minimization of the effect of silicon chemical form in xylene on ICP-AES
performance, J. Anal. At. Spectrom., 24/10 (2009) 1382-1388.  DOI: 10.1039/b906568g

K.D. Summerhays, P.J. Lamothe, T.L. Fries, Volatile Species in Inductively Coupled Plasma Atomic Emission Spectroscopy: Implications for Enhanced Sensitivity, Appl. Spectrosc., 37/1 (1983) 25-28. DOI: 10.1366/0003702834634136

  Alfredo Sanz-Medel, J. Enrique Sánchez-Uría, Siro Arribas Jimeno, Enhancement of Molybdenum ICP-Emission by Forming Volatile Species in Organic Solvents, Analyst (London), 110/5 (1985) 563-569. DOI: 10.1039/AN9851000563

 J.M. Bazan, Enhancement of Osmium Detection in Inductively Coupled Plasma Atomic Emission Spectrometry, Anal. Chem., 59/7 (1987) 1066-1069. DOI: 10.1021/ac00134a031

 Angel López-Molinero, J.R. Castillo-Suarez, J.M. Mermet, Observations on the determination of osmium by inductively-coupled plasma atomic emission spectroscopy, Talanta, 37/9 (1990) 895-899. doi:10.1016/0039-9140(90)80249-F

 T.D. Martin, C.A. Brockhoff, J.T. Creed, Trace metal valence state consideration in utilizing an ultrasonic nebulizer for metal determination by inductively coupled plasma atomic emission spectrometry (ICP-AES), ICP Inf. Newsl., 19 (1994) 730.

 John T. Creed, Theodore D. Martin, Carol A. Brockhoff, Ultrasonic Nebulization and Arsenic Valence State Considerations Prior to Determination via Inductively Coupled Plasma Mass Spectrometry, J. Anal. At. Spectrom., 10/6 (1995) 443-447. DOI: 10.1039/JA9951000443

 Jin-fu Yang, John A. Koropchak, Valence Discrimination Effects with Thermospray Sample Introduction: Characterization and Prevention, Appl. Spectrosc., 51/10 (1997) 1573-1578. DOI:10.1366/0003702971939127

 R.C. Richter, S.R. Koirtyohann, S.S. Jurisson, Determination of technetium-99 in Aqueous Solutions by Inductively Coupled Plasma Mass Spectrometry: Effects of Chemical Form and Memory, J. Anal. At. Spectrom., 12/5 (1997) 557-562. DOI: 10.1039/a606483c

 Assad S. Al-Ammar, Rajesh K. Gupta, Ramon M. Barnes, Correction for volatility differences between organic sample analytes and standards in organic solutions analyzed by inductively coupled plasma-atomic emission and mass spectrometry, J. Anal. At. Spectrom., 14/5 (1999) 793-799. DOI: 10.1039/a808391f

 B. Langlois, Determination of iodine at ppt level in a nitric acid medium by ICP sector field mass spectrometry : influence of chemical forms, Ph.D. Thesis, University Lyon I, France, 2001, pp. 300.

 A.M. Featherstone, A.T. Townsend, G.A. Jacobson, G.M. Peterson, Comparison of methods for the determination of total selenium in plasma by magnetic sector inductively coupled plasma mass spectrometry, Anal. Chim. Acta, 512/2 (2004) 319-327. doi:10.1016/j.aca.2004.02.058  

 Lee L. Yu, Therese A. Butler, Gregory C. Turk, Effect of Valence State on ICP-OES Value Assignment of SRM 3103a Arsenic Spectrometric Solution, Anal. Chem., 78/5 (2006) 1651-1656. doi: 10.1021/ac051732i

 Dijana Juresa, Doris Kuehnelt, Kevin A. Francesconi, Consequences of Vapor Enhancement on Selenium Speciation Analysis by HPLC/ICPMS, Anal. Chem., 78/24 (2006) 8569-8574. DOI: 10.1021/ac061496r

 Dijana Juresa, Jerome Darrouzes, Norbert Kienzl, Maite Bueno, Florence Pannier, Martine Potin-Gautier, Kevin A. Francesconi, Doris Kuehnelt, An HPLC/ICPMS study of the stability of selenosugars in human urine: implications for quantification, sample handling, and storage, J. Anal. At. Spectrom., 21/7 (2006) 684-690. DOI: 10.1039/b602976k

Tomohiro Narukawa, Takayoshi Kuroiwa, Koichi Chiba, Mechanism of sensitivity difference between trivalent inorganic As species [As(III)] and pentavalent species [As(V)] with inductively coupled plasma spectrometry, Talanta, 73/1 (2007) 157-165. doi: 10.1016/j.talanta.2007.03.021

Related EVISA Resources:

Brief summary: ICP-MS: A versatile detection system for speciation analysis
Link Database: All about silicon

Related EVISA News

December 15, 2006, Speciation matters even if the interest is in total element concentration

last time modified: September 30, 2009


Imprint     Disclaimer

© 2003 - 2010 by European Virtual Institute for Speciation Analysis ( EVISA )