Application of negative ions in inductively coupled plasma-mass spectrometry / Pupyshev AA,Surikov V // SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY. - 2004. - V. 59, l. 7. - P. 1021-1031.

ISSN/EISSN:

0584-8547 / нет данных

Type:

Article

Abstract:

The efficiency of the formation of negative background and F-, Cl-, Br- and I- ions in inductively coupled plasma (ICP) was investigated at temperatures ranging from 4000 to 9000 K using thermodynamic simulation. It was shown that the basic negative background ions in ICP, O-, H-. OH- and probably Ar-, are in accordance with experiment. The estimated total concentration of negative ions in ICP was found to be four to five orders of magnitude smaller than that of positive ions. The highest efficiency of negative ion formation should be observed for elements having high electron affinity, namely Cl, F, Br and I. However, the detection sensitivity in the negative ion detection mode may be increased slightly as compared with the positive ion detection mode only for fluorine in the temperature range 6000-7000 K. This is in contradiction with experimental results and may be explained by the formation of negative ions behind the skimmer and/or smaller losses of negative ions in the ion beam at low ionic current. The relationship between the efficiency of negative atomic ion formation and electron affinity was determined. This makes it possible to estimate numerically the efficiency of the formation of Ar-, Na- and other negative atomic ions in the ICP. The calculations performed confirmed the experimental data showing that the cation (Ba, Co, Cu, K, Na and Sr) introduced as a chloride does not affect the analytical signal of Cl-. According to the calculations, high contents of halogens in samples are not expected to alter significantly the contents of F-, Cl-, Br- and F measured in ICP as analytes. The experimentally observed significant suppression effect of high halogen concentrations may be caused by a shift of equilibrium in rcactions of electron addition to halogen atoms behind the skimmer and/or increased negative ion current in the ion beam and accordingly greater losses of analytes. (C) 2004 Elsevier B.V. All rights reserved.

Author keywords:

inductively coupled plasma-mass spectrometry; thermodynamic simulation; negative atomic and molecular ions; efficiency of ion formation; matrix effects THERMODYNAMIC SIMULATION; THERMOCHEMICAL PROCESSES; VACUUM INTERFACE; GAS

DOI:

10.1016/j.sab.2004.05.011

Web of Science ID:

ISI:000223388400011

Соавторы в МНС:

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Другие поля

Поле	Значение
Month	JUL 30
Publisher	PERGAMON-ELSEVIER SCIENCE LTD
Address	THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
Language	English
Keywords-Plus	THERMODYNAMIC SIMULATION; THERMOCHEMICAL PROCESSES; VACUUM INTERFACE; GAS
Research-Areas	Spectroscopy
Web-of-Science-Categories	Spectroscopy
Author-Email	pupyshev@dpt.ustu.ru
ORCID-Numbers	Pupyshev, Alexander/0000-0003-2484-5377
Number-of-Cited-References	34
Usage-Count-Since-2013	7
Journal-ISO	Spectroc. Acta Pt. B-Atom. Spectr.
Doc-Delivery-Number	847JL