Use of a Temperature-programmable Injector Coupled to Gas Chromatography-combustion-isotope Ratio Mass Spectrometry for Compound-specific Carbon Isotopic Analysis of Polycyclic Aromatic Hydrocarbons

Compound Specific Isotopic Analysis (CSIA) can provide information about the origin of analyzed compounds for instance polycyclic aromatic hydrocarbons (PAHs) in aerosols. This could be a valuable tool in source apportionment of particulate matter (PM) air pollution. Because gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS) analysis requires an amount of at least 10 ng of an individual PAH, a high concentration of PAHs in the injected extract is needed. When the concentration is low a large volume injector creates the possibility of introducing a satisfactory amount of individual PAHs. In this study the temperature programmable injector was coupled to GC-C-IRMS and injection parameters (solvent level, transfer column flow, transfers time) were optimized using six solid aromatic compounds (anthracene, fluoranthene, pyrene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene) dissolved in n-pentane and EPA 610 reference mixture. Solid PAHs CSIA results were compared to results obtained for the single components analysed with elemental analysis - isotope ratio mass spectrometry. The injection method was validated for two sample injection volumes, 50 and 100 µL. This method was also compared with commonly used splitless injection. To be included in the study measurements had to have an uncertainty lower than 0.5 per mille for dVPDB 13C and minimum peak height of 200 mV. The lower concentration limit at which these criteria were fulfilled for PAHs were 30 2ng/µl for 1 µl of splitless injection and 0.3 and 0.2ng/µl for 50 and 100 µl of large volume injection respectively.

MIKOLAJCZUK Agnieszka;  GEYPENS Benny;  BERGLUND Michael;  TAYLOR Philip; 

2009-07-23

JOHN WILEY & SONS LTD

JRC49496

0951-4198,   

http://www3.interscience.wiley.com/cgi-bin/fulltext/122512526/PDFSTART,    https://publications.jrc.ec.europa.eu/repository/handle/JRC49496,   

10.1002/rcm.4027,