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Mass-spectrometry with
ionization by inductively-coupled plasma and laser sampling system:
application to geological problems.
Kapitonov I.N.*,
Goltsin N.A.*, Lokhov K.I*., Sergeev S.A.*
*
A.P. Karpinsky
Russian Geological Research Institute,
,St-Petersburg, Russia.
**
**SPb state university,St-Petersburg, Russia.
Igor_Kapitonov@vsegei.ru
The studies by laser sampling system (laser ablation, LA) combined with
inductively-coupled plasma mass-spectrometer are relatively new, but
very informative method as in geologic investigations as and in many
other fields of science. The absence of complex chemical sample
preparation and the ability to see the object of study during the
analysis, ability to study heterogeneous objects makes the method
particularly attractive.
At the present time, secondary-ion mass spectrometers (SIMS) have the
best characteristics in terms of locality. They allow you to obtain a
spatial resolution of of several microns along the sample surface
(determined by the diameter of the beam of primary ions) and nanometer
resolution level in the stratified analysis into the sample. Laser
ablation system does not have such a good locality, but nevertheless
are becoming more widely available. This is due to several factors,
among which include the following:
Lower Cost
The smaller size
Higher productivity
Finally, significantly higher precision in the isotope studies (by using
multicollector) allows solve some isotope tasks by LA-ICPMS at the
level, which is not available for modern SIMS analytical systems.
At the centre of isotopic research of A.P. Karpinsky Russian Geological
Research Institute (VSEGEI) LA-ICPMS complex equipped with laser
ablation system DUV-193 with ArF excimer laser, mass-spectrometer
Element-2 (ICPMS) and multicollector mass-spectrometer Neptune (MC-ICPMS).
The report will be submitted to the experience of more than 7 years of
operation of this complex and its analytical application for solving
geochronological problems such as U-Pb dating of high-uranium zircons,
detrital zircon, baddeleyite, high-uranium inclusion in a minerals [e.g.
Alexeev N.L, e.a, 2010; Chumakov, N,
2011; N.V. Rodionov, e.a, 2012],
high-precision determination of lead isotope ratios in lead-containing
sulfides. Along with the objectives of geochronological method, the
laser ablation is widely used in centere of isotopic research for
solving problems of the rocks and minerals genesis. The exsamples and
methods of Hf isotope composition in the zircon [e.g. Lokhov K.I.
, e.a, 2009] and baddeleyite, rare
earth elements determination in the same minerals [e.g. N.V.
Rodionov, e.a, 2012],
and in such mineral as apatite, scheelite and garnet.
The same method of laser ablation has worked well in measuring of osmium
isotopic composition in osmium minerals and osmium-containing sulfides,
rapid monitoring of the isotopic composition of carbon in shungite [I.
Kapitonov,2008], measurements of trace
elements in various minerals[e.g. J. Gotze,
e.a, 2009].
Literature
Alexeev N.L., Glebovitsky V.A., Zinger T.F.,
Kapitonov I.N. U-Pb age of igneous and metamorphic events on the Fisher
massif (east Antarctica) and its significance for geodynamic
reconstruction // Doklady Earth Sciences, 2010, v.435, N 1,
p.1435-1441..
Lokhov K.I., Saltykova T.E., Kapitonov I.N., e.a.
Correct interpretation of isotopic U-Pb zircon age by isotopic
geochemistry of hafnium and neodymium (on example of some magmatic
complexes of the basement of the East – European platform). // Regional
Geology and Metallogeny 2009. № 38. С. 43-53. (in Russian).
Chumakov, N. · Kapitonov, I. · Semikhatov, M. ·
Leonov, M. · Rud'ko, S. Vendian age of the upper part of the patom
complex in Middle Siberia: U/Pb LA-ICPMS dates of detrital zircons from
the Nikol'skoe and Zherba formations
Journal Stratigraphy and Geological Correlation V 19,
N 2, march-april 2011, p. 115-119
I. Kapitonov, E. Prilepsky, K. Lokhov, S. Sergeev.
Experience of the high-speed monitoring of 13C/12C isotope ratio in
schungite by LA-ICPMS technique. 33rd IGC, Oslo, 2008,
http://www.cprm.gov.br/33IGC/1336007.html
J. Gotze, R. Mockel, U. Kempe, I. Kapitonov, and T.
Vennemann. Characteristics and origin of agates in sedimentary rocks
from the Dryhead area, Montana, USA, Mineralogical Magazine, 2009;
73(4): 673 - 690.
N.V. Rodionov, B.V. Belyatsky, A.V. Antonov, I.N.
Kapitonov, S.A. Sergeev. Comparative in-situ U–Th–Pb geochronology and
trace element composition of baddeleyite and low-U zircon from
carbonatites of the Palaeozoic Kovdor alkaline–ultramafic complex, Kola
Peninsula, Russia, Gondwana Research,Volume 21, Issue 4, 2012, p.
728–744. |