Inter‐laboratory comparison of elemental analysis and gas chromatography combustion isotope ratio mass spectrometry (GC‐C‐IRMS). Part I: δ¹³C measurements of selected compounds for the development of an isotopic Grob‐test

Abstract

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.

The Genome Characteristics and Predicted Function of Methyl-Group Oxidation Pathway in the Obligate Aceticlastic Methanogens, Methanosaeta spp

“…Methane and acetate were determined by gas chromatograph GC-14B (Shimadzu) and CO 2 was determined by gas chromatograph GC-14C (Shimadzu) [8], [40]. The stable isotope composition was determined by Trace GC/IsoLink/Delta V Advantage GC/IRMS (Thermo Fisher Scientific, Bremen, Germany) [41], [42].…”

Performance evaluation of elemental analysis/isotope ratio mass spectrometry methods for the determination of the D/H ratio in tetramethylurea and other compounds – results of a laboratory inter‐comparison

“…In order to evaluate the performance parameters of the method and to explore the diversity of the matrices, it was decided to distribute three types of samples: Water: 3 samples (Nantes Tap Water, NTW; Ispra Tap Water, ITW; Enriched Fermentation Water, EFW = water prepared by dilution of D 2 O with tap water, used for fermentation of fruit juice concentrates in the laboratory); Tetramethylurea (C 5 H 12 N 2 O/(CH 3 ) 2 NCON(CH 3 ) 2 , CAS 632‐22‐4): 3 samples from the last 3 previous batches of this internal standard for SNIF‐NMR® measurements (Batch 97, Batch 01 and Batch 04); Organic compounds: 3 samples from the EU project GC‐IRMS (G6RD‐CT‐2001‐00515, short inter laboratory study, 4 labs),6 dodecane (C 12 H 26 , CAS 112‐40‐3), methyl dodecanoate (C 13 H 26 O 2 , CAS 111‐82‐0) and methyl N ‐methylanthranilate (C 9 H 11 NO 2 , CAS 85‐91‐6). …”

Comparative analysis of 1-phenyl-2-propanone (P2P), an amphetamine-type stimulant precursor, using stable isotope ratio mass spectrometry

“…The CO 2 reference gas (purity 4.5, Linde, München, Germany) was calibrated against three working standards (dodecane, methyldecanoate, methyldodecanoate) with well-known δ 13 C V-PDB values [15].…”