Linked Life Data

17518225

Source:http://linkedlifedata.com/resource/pubmed/id/17518225

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2007-5-23
pubmed:abstractText
Organic carbon (OC) was measured semicontinuously in laboratory experiments of steady-state secondary organic aerosol formed by hydrocarbon + nitrogen oxide irradiations. Examination of the mass of carbon measured on the filter for various sample volumes reveals a systematic offset that is not observed when performing an instrumental blank. These findings suggest that simple subtraction of instrumental blanks determined as the standard analysis without sample collection (i.e., by cycling the pump and valves yet filtering zero liters of air followed by routine chemical analysis) from measured concentrations may be inadequate. This may be especially true for samples collected through the filtration of small air volumes wherein the influence of the systematic offset is greatest. All of the experiments show that filtering a larger volume of air minimizes the influence of contributions from the systematic offset. Application of these results to measurements of ambient concentrations of carbonaceous aerosol suggests a need for collection of sufficient carbon mass to minimize the relative influence of the offset signal.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
1096-2247
pubmed:author
pubmed:issnType
Print
pubmed:volume
57
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
596-9
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Investigation of a systematic offset in the measurement of organic carbon with a semicontinuous analyzer.
pubmed:affiliation
U.S. Environmental Protection Agency, National Exposure Research Laboratory, Human Exposure Atmospheric Sciences Division, Research Triangle Park, NC 27711, USA. offenberg.john@epa.gov
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S.