Systematic errors in gas chromatography: mass spectrometry isotope ratio measurements. [Mass cycling error]

Journal Article · Sun Aug 01 00:00:00 EDT 1976 · Anal. Chem.; (United States)

DOI:https://doi.org/10.1021/ac50003a028· OSTI ID:7353335

Matthews, D E; Hayes, J M

The mass cycling error, a systematic bias inherent in isotope ratio measurements carried out by switching ion beams which are time-variable, is systematically explored in a series of trial calculations, and the validity of these calculations is demonstrated experimentally using a typical gas chromatography-mass spectrometry system. The effects of varying measurement conditions are considered in terms of chromatographic peak profiles, relative ion-beam integration times, delays required for ion-beam positioning, unidirectional vs. bidirectional scanning patterns, and chromatographic fractionation of the isotopes. It is concluded that the unidirectional scanning pattern (ABCABC...) is superior to the bidirectional pattern (ABCCBA...), and that, in the absence of chromatographic fractionation of the isotopes, a bias of less than 1 percent can be obtained by its use for ten or more cycles on any given gas chromatographic peak. Under these same conditions, 35 or more observation cycles are required to bring the bias below 0.1 percent.

• Research Organization: Indiana Univ., Bloomington
• OSTI ID: 7353335
• Journal Information: Anal. Chem.; (United States), Vol. 48:9
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
GAS CHROMATOGRAPHY
ERRORS
ISOTOPE RATIO
MASS SPECTROSCOPY
ACCURACY
ELECTRON MULTIPLIER DETECTORS
ION BEAMS
MEASURING METHODS
STATISTICS
BEAMS
CHROMATOGRAPHY
MATHEMATICS
MEASURING INSTRUMENTS
RADIATION DETECTORS
SEPARATION PROCESSES
SPECTROSCOPY
400104* - Spectral Procedures- (-1987)
400105 - Separation Procedures