Send to

Choose Destination
See comment in PubMed Commons below
Chemosphere. 2009 Mar;75(1):92-9. doi: 10.1016/j.chemosphere.2008.11.044. Epub 2008 Dec 23.

The effect of acidification on the determination of elemental carbon, char-, and soot-elemental carbon in soils and sediments.

Author information

  • 1SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710075, China.


We studied the influence of acid pretreatment on the effective distinction between elemental carbon (EC) and organic carbon (OC), and between char-EC and soot-EC. Though widely employed in the pretreatment of soils and sediments for EC quantification, the use of HCl, HF, and HNO(3) could decrease soot thermal stability as acid remains, leading to an underestimation of soot-EC by thermal methods. We compared thermal optical reflectance (TOR) measurements of EC concentrations in char reference materials and in lacustrine and marine sediments following pretreatment with various acids. The results showed that pretreatment with 2M HCl, concentrated HNO(3), 7 M HNO(3), and 1 M HNO(3) did not result in EC oxidation. However, hot concentrated HNO(3) oxidized EC significantly, leading to lower concentrations of EC, char-EC and soot-EC. By comparing the removal of potentially interfering materials, which contain little fire-derived carbon, with different acid pretreatments, we recommend the HCl-HF-HCl and concentrated (not hot) HNO(3)-HF-HCl pretreatments for the determination of EC, char-EC, and soot-EC in soils and sediments using the TOR method.

[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science
    Loading ...
    Write to the Help Desk