Background effects on Faraday collectors in gas-source mass spectrometry   and implications for clumped isotope measurements

doi:10.1002/rcm.6490

CORC > 北京大学 > 地球与空间科学学院

	Background effects on Faraday collectors in gas-source mass spectrometry and implications for clumped isotope measurements
	Bernasconi, Stefano M. ; Hu, Bin ; Wacker, Ulrike ; Fiebig, Jens ; Breitenbach, Sebastian F. M. ; Rutz, Tanja
刊名	质谱学快讯
	2013
关键词	CARBONATE MINERALS C-13-O-18 BONDS PALEOTHERMOMETER THERMOMETRY CO2
DOI	10.1002/rcm.6490
英文摘要	RATIONALE The measurement of the abundances of minor isotopologues by mass spectrometry requires correction of subtle non-linearities in the mass spectrometer that cause deviations in the relationship between actual and measured isotope ratios. Here we show that negative backgrounds on the Faraday cups recording the minor ion beams are the cause of the observed non-linearities in the measurement of CO2 isotopologues, and propose a new correction procedure for clumped isotope measurements. METHODS We carefully investigated the cause of non-linearity effects in the measurement of the abundance of 13C18O16O, a minor isotopologue of CO2 with m/z 47, on two different mass spectrometers. By using gases of different composition with close to stochastic and with non-random distribution of isotopes we demonstrate that the apparent dependence of the excess abundance of the isotopologue of m/z 47 on the bulk isotopic composition of CO2 is due to a background interference that is linearly dependent on the partial pressure of the gas in the source of the mass spectrometer. CONCLUSIONS Background determination with gas flowing into the source of the mass spectrometer is necessary for accurate clumped isotope measurements of CO2. Background corrections can be performed accurately if the slit width of the m/z 44 Faraday cup significantly exceeds that of the one for m/z 47, using a correlation between m/z 44 signal intensity and the corresponding minimum in m/z 47 background. We propose two new correction schemes that reduce the time-consuming measurement of gases of different bulk isotopic compositions. These findings may also be relevant for the measurement of other rare isotopologues by mass spectrometry. Copyright (c) 2013 John Wiley & Sons, Ltd.; Biochemical Research Methods; Chemistry, Analytical; Spectroscopy; SCI(E); 10; ARTICLE; 5; 603-612; 27
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/225712]
专题	地球与空间科学学院
推荐引用方式 GB/T 7714	Bernasconi, Stefano M.,Hu, Bin,Wacker, Ulrike,et al. Background effects on Faraday collectors in gas-source mass spectrometry and implications for clumped isotope measurements[J]. 质谱学快讯,2013.
APA	Bernasconi, Stefano M.,Hu, Bin,Wacker, Ulrike,Fiebig, Jens,Breitenbach, Sebastian F. M.,&Rutz, Tanja.(2013).Background effects on Faraday collectors in gas-source mass spectrometry and implications for clumped isotope measurements.质谱学快讯.
MLA	Bernasconi, Stefano M.,et al."Background effects on Faraday collectors in gas-source mass spectrometry and implications for clumped isotope measurements".质谱学快讯 (2013).