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Absorption coefficient modified pressed powders for calibration of laser ablation inductively coupled plasma mass spectrometry
journal contribution
posted on 2007-06-04, 08:19 authored by Ciaran O'Connor, Mark R. Landon, Barry SharpPowdered samples have been pressed, utilising a standard KBr infrared (IR) press, to
produce mechanically stable 13 mm discs. Three ‘absorbing’, organic based binders
have been employed in this work; vanillic acid, pyrazinoic acid and nicotinic acid,
chosen because of their high optical absorbance at the wavelength of the incident laser
energy (213 nm). Poly(vinyl alcohol) (PVA) was employed as an example of a ‘nonabsorbing’
binder and because its use has been described previously in the literature.
Discs of various sample/binder compositions were prepared, and their absorption
properties characterised by diffuse reflectance spectroscopy. Laser Ablation
Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) was used to
investigate the effect of different sample/binder compositions on signal sensitivity;
whilst surface profilometry was performed on the resulting tracks to provide an
estimate of the ablation depth achieved by the laser beam. It was found that discs
prepared with vanillic acid had the highest optical absorbance at the wavelength of the
laser system employed, resulting in a lower ablation depth and improved signal
sensitivity probably through the formation of smaller particles during the ablation
process.
Analysis of certified reference materials (CRMs) was performed using simple external
calibration standards of similar and dissimilar CRMs. It was found that discs
produced using a 40% vanillic acid binder, 60% sample composition gave superior
quality analytical data when compared to the use of 40% PVA binder or no binder at
all. These findings indicate the potential for good quality analytical data to be
obtained when employing external calibration standards, without internal standardisation and without exact matrix matching. These data also provide further
evidence that standardisation of ablation conditions and mass flux to the plasma are
pre-requisites for robust calibration, particularly in the absence of a suitable internal
standard element.
History
School
- Science
Department
- Chemistry
Citation
O'CONNOR, C. LANDON, M.R. and SHARP, B.L. (2007). Absorption coefficient modified pressed powders for calibration of laser ablation inductively coupled plasma mass spectrometry. Journal of Analytical Atomic Spectrometry, 22 (3), pp. 273-282.Publisher
© RSC PublishingPublication date
2007Notes
This article was published in the journal, Journal of Analytical Atomic Spectrometry [© RSC Publishing], and is available at: http://www.rsc.org/Publishing/Journals/JA/article.asp?doi=b612512c (N.B. This article may not be further made available or distributed.)ISSN
1364-5544;0267-9477Language
- en