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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
2006-4-28
pubmed:abstractText
Primary gravimetric gas cylinder standards containing 30 volatile organic compounds (VOCs) in nitrogen were prepared using a procedure previously developed to prepare gas mixture cylinder standards of VOCs at the 5 nmol/mol level. This set of primary standards was intercompared to existing gas cylinder standards, containing as many as 19 of the 30 volatile organics present in these new primaries, using gas chromatography with a hydrogen flame ionization detector coupled with cryogenic preconcentration. The linear regression analysis showed excellent agreement among the standards for each compound. Similar mixtures containing many of these compounds in treated aluminum gas cylinders have been evaluated over time and have shown stability for as much as 10 years. The development of these 30-component primary standards led to the preparation and certification of a reissue of Standard Reference Material (SRM) 1804 at the nominal amount-of-substance fraction of 5 nmol/mol for each analyte. A lot of 20 cylinders containing the mixture was prepared at NIST following previously demonstrated protocols for preparation of the cylinders. Each cylinder was analyzed against one cylinder from the lot, designated as the "lot standard," for each of the 30 compounds. As a result of the uncertainty analysis, the data showed that rather than declaring the lot homogeneous with a much higher uncertainty, each cylinder could be individually certified. The expanded uncertainty limits ranged from 1.5 to 10% for 28 of the 30 analytes, with two of the analytes having uncertainties as high as 19% in those SRM cylinders certified. Due to stability issues and some high uncertainties for a few analytes in 2 of the samples, 18 of the 20 candidate SRM samples were certified. These volatile organic gas mixtures represent the most complex gas SRMs developed at NIST.
pubmed:language
eng
pubmed:journal
pubmed:status
PubMed-not-MEDLINE
pubmed:month
May
pubmed:issn
0003-2700
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
78
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3125-32
pubmed:year
2006
pubmed:articleTitle
Development of a NIST standard reference material containing thirty volatile organic compounds at 5 nmol/mol in nitrogen.
pubmed:affiliation
Analytical Chemistry Division and Statistical Engineering Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8393, USA. george.rhoderick@nist.gov
pubmed:publicationType
Journal Article