PMID- 11563656
OWN - NLM
STAT- MEDLINE
DCOM- 20020123
LR  - 20191210
IS  - 0013-936X (Print)
IS  - 0013-936X (Linking)
VI  - 35
IP  - 17
DP  - 2001 Sep 1
TI  - An improved thermal oxidation method for the quantification of soot/graphitic 
      black carbon in sediments and soils.
PG  - 3519-25
AB  - Recent findings have confirmed the importance of black carbon (BC) in the global 
      biogeochemical cycles of carbon and oxygen through its important contribution to 
      the slowly cycling organic carbon (OC) pool. Yet, most BC determination methods 
      published to date measure operationally defined BC fractions, oftentimes with a 
      high potential for artifacts and a lack of specificity for one of the two major 
      forms of the BC continuum, soot/graphitic BC (GBC) and char/charcoal BC (CBC). 
      This paper describes a method that reduces the potential for artifacts to 
      accurately and selectively measure the concentration of GBC in complex mineral 
      and organic matrixes. Marine and lacustrine sediments, river sediments, suspended 
      particles, and a marine plankton sample were first demineralized with a mixture 
      of hydrochloric (HCl) and hydrofluoric (HF) acids to expose any biochemical 
      entrapped in a mineral matrix. The hydrolyzable organic matter fraction (mostly 
      proteins and carbohydrates) was then removed with 02-free trifluoroacetic acid 
      and HCl, after which the non-GBC, non-hydrolyzable OC fraction was finally 
      removed by thermal oxidation at 375 degrees C for 24 h. The specificity of the 
      method for GBC was assessed with pure CBC and GBC samples. Detection limit and 
      GBC recovery in spiked samples were 10 mg kg(-1) and approximately 85%, 
      respectively. Typical GBC concentrations measured in a series of natural samples 
      ranged from <10 mg kg(-1) in marine plankton to 0.19% in a riverine sample. These 
      concentrations were lower by as much as 3 orders of magnitude than those obtained 
      by thermal oxidation without demineralization and removal of hydrolyzable organic 
      matter. The improvements presented in this work allow for the accurate and 
      precise measurement of GBC in complex organic and mineral matrixes by eliminating 
      the interference caused by the presence of CBC, residual non-BC OC and minerals, 
      or by the formation of condensation products that could account for as much as 
      4-6% of total OC. Combined to stable and radioisotope analysis, this improved 
      method should permit quantitative assessments of the role and dynamics of GBC in 
      the global geochemical cycles of carbon and oxygen.
FAU - Gelinas, Y
AU  - Gelinas Y
AD  - School of Oceanography, University of Washington, Seattle 98195-7940, USA. 
      gelinas@ocean.washington.edu
FAU - Prentice, K M
AU  - Prentice KM
FAU - Baldock, J A
AU  - Baldock JA
FAU - Hedges, J I
AU  - Hedges JI
LA  - eng
PT  - Evaluation Study
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - Environ Sci Technol
JT  - Environmental science & technology
JID - 0213155
RN  - 0 (Organic Chemicals)
RN  - 0 (Soil Pollutants)
RN  - 7440-44-0 (Carbon)
RN  - 7782-42-5 (Graphite)
RN  - S88TT14065 (Oxygen)
SB  - IM
MH  - Animals
MH  - *Artifacts
MH  - Carbon/*metabolism
MH  - Environmental Monitoring/*methods
MH  - Geologic Sediments/chemistry
MH  - Graphite/*analysis
MH  - Organic Chemicals
MH  - Oxidation-Reduction
MH  - Oxygen/metabolism
MH  - Plankton
MH  - Sensitivity and Specificity
MH  - Soil Pollutants/*analysis
MH  - Temperature
EDAT- 2001/09/21 10:00
MHDA- 2002/01/24 10:01
CRDT- 2001/09/21 10:00
PHST- 2001/09/21 10:00 [pubmed]
PHST- 2002/01/24 10:01 [medline]
PHST- 2001/09/21 10:00 [entrez]
AID - 10.1021/es010504c [doi]
PST - ppublish
SO  - Environ Sci Technol. 2001 Sep 1;35(17):3519-25. doi: 10.1021/es010504c.