Premium
A new gas inlet system for an isotope ratio mass spectrometer improves reproducibility
Author(s) -
Leuenberger M.,
Nyfeler P.,
Moret H. P.,
Sturm P.,
Huber Ch.
Publication year - 2000
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/1097-0231(20000830)14:16<1543::aid-rcm62>3.0.co;2-h
Subject(s) - chemistry , reproducibility , inlet , mass spectrometry , analytical chemistry (journal) , isotope ratio mass spectrometry , desorption , isotope , volumetric flow rate , adsorption , chromatography , mechanics , mechanical engineering , physics , organic chemistry , quantum mechanics , engineering
We have developed a new inlet system for a gas sample isotope ratio mass spectrometer (IRMS). It is based on the well‐known open split design from the gas chromatography/mass spectrometry (GC/MS) system due to its simplicity. The advantages over the conventional double inlet system with the metal bellows design include an improved reproducibility mainly due to a highly controllable pressure and temperature adjustment, a markedly lowered memory effect due to an uninterrupted gas flow through the ion source which limits adsorption/desorption processes on surfaces, and a single inlet capillary circumventing problems of asymmetrical behavior of sample and reference inlet paths. Furthermore, sample consumption is of the same order as for conventional measurements (i.e. about 0.4 mmol per hour), of which however only 2 µmol/h is used for the actual isotope ratio determination since the major gas amount acts as a gas flow seal against the atmosphere, corresponding to a 100–200 fold overkill. This may be improved in future systems. Copyright © 2000 John Wiley & Sons, Ltd.