title: Compound-specific stable carbon isotopic signature of carbohydrate pyrolysis products from C3 and C4 plants.
abstract: BACKGROUND
  Pyrolysis-compound specific isotopic analysis (Py-CSIA: Py-GC-(FID)-C-IRMS) is a relatively novel technique that allows on-line quantification of stable isotope proportions in chromatographically separated products released by pyrolysis. Validation of the Py-CSIA technique is compulsory for molecular traceability in basic and applied research. In this work, commercial sucrose from C4 (sugarcane) and C3 (sugarbeet) photosystem plants and admixtures were studied using analytical pyrolysis (Py-GC/MS), bulk δ(13)C IRMS and δ(13)C Py-CSIA.
  
  
  RESULTS
  Major pyrolysis compounds were furfural (F), furfural-5-hydroxymethyl (HMF) and levoglucosan (LV). Bulk and main pyrolysis compound δ(13)C (‰) values were dependent on plant origin: C3 (F, -24.65 ± 0.89; HMF, -22.07 ± 0.41‰; LV, -21.74 ± 0.17‰) and C4 (F, -14.35 ± 0.89‰; HMF, -11.22 ± 0.54‰; LV, -11.44 ± 1.26‰). Significant regressions were obtained for δ(13)C of bulk and pyrolysis compounds in C3 and C4 admixtures. Furfural (F) was found (13)C depleted with respect to bulk and HMF and LV, indicating the incorporation of the light carbon atom in position 6 of carbohydrates in the furan ring after pyrolysis.
  
  
  CONCLUSIONS
  This is the first detailed report on the δ(13)C signature of major pyrolytically generated carbohydrate-derived molecules. The information provided by Py-CSIA is valuable for identifying source marker compounds of use in food science/fraud detection or in environmental research.
authors.affiliation: IRNAS-CSIC, Av. Reina Mercedes, 10, 41012, -Seville, Spain.
authors.forename: José A
authors.initials: JA
authors.lastname: González-Pérez
authors.affiliation: IRNAS-CSIC, Av. Reina Mercedes, 10, 41012, -Seville, Spain.
authors.forename: Nicasio T
authors.initials: NT
authors.lastname: Jiménez-Morillo
authors.affiliation: IRNAS-CSIC, Av. Reina Mercedes, 10, 41012, -Seville, Spain.
authors.forename: José M
authors.initials: JM
authors.lastname: de la Rosa
authors.affiliation: MNCN-CSIC, c/Serrano 115-B, 28006, -Madrid, Spain.
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Almendros
authors.affiliation: IRNAS-CSIC, Av. Reina Mercedes, 10, 41012, -Seville, Spain.
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: González-Vila
mesh_terms: D002241:Carbohydrates / Q000737:chemistry; D002247:Carbon Isotopes / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D010944:Plants / Q000737:chemistry*
chemical_list: D002241:Carbohydrates; D002247:Carbon Isotopes
keywords: analytical pyrolysis; furfural; furfural-5-hydroxymethyl (HMF); levoglucosan; stable carbon isotopes; sucrose