Inter-laboratory comparison of elemental analysis and gas chromatography combustion isotope ratio mass spectrometry (GC-C-IRMS). Part I: delta13C measurements of selected compounds for the development of an isotopic Grob-test.
This study was directed towards investigating suitable compounds to be used as stable isotope reference materials for gas chromatography combustion isotope ratio mass spectrometry (GC-C-IRMS) calibration. Several compounds were selected from those used in the 'Grob-test' mixture. Oxygen- and nitrogen-containing substances were added to these compounds to allow the mixture to be used as a possible multi-isotopic calibration tool for 2H/1H, 13C/12C, 15N/14N and 18O/16O ratio determinations. In this paper we present the results of delta13C measurements performed by the consortium of the five laboratories taking part in this inter-calibration exercise. All the compounds were individually assessed for homogeneity, short-term stability and long-term stability by means of EA-IRMS, as required by the bureau communitaire de reference (BCR) Guide for Production of Certified Reference Materials. The results were compared then with the GC-C-IRMS measurements using both polar and non-polar columns, and the final mixture of selected compounds underwent a further certification exercise assessing limits of accuracy and reproducibility under specified GC-C-IRMS conditions.
Serra
F
F
European Commission, Joint Research Centre, Institute for Health and Consumer Protection, Physical and Chemical Exposure Unit, BEVABS, 21020 Ispra (VA), Italy. francesca.serra@jrc.it
Janeiro
A
A
Calderone
G
G
Rojas
J M Moreno
JM
Rhodes
C
C
Gonthier
L A
LA
Martin
F
F
Lees
M
M
Mosandl
A
A
Sewenig
S
S
Hener
U
U
Henriques
B
B
Ramalho
L
L
Reniero
F
F
Teixeira
A J
AJ
Guillou
C
C
D002247:Carbon Isotopes / Q000737:chemistry* / Q000592:standards*; D005060:Europe; D005504:Food Analysis / Q000592:standards*; D008401:Gas Chromatography-Mass Spectrometry / Q000592:standards*; D007753:Laboratories / Q000592:standards*; D012016:Reference Values
D002247:Carbon Isotopes