Source:http://linkedlifedata.com/resource/pubmed/id/19196521
Switch to
| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
4
|
| pubmed:dateCreated |
2009-3-23
|
| pubmed:abstractText |
The positive APCI-mass spectra in air of linear (n-pentane, n-hexane, n-heptane, n-octane), branched [2,4-dimethylpentane, 2,2-dimethylpentane and 2,2,4-trimethylpentane (i-octane)], and cyclic (cyclohexane) alkanes were analyzed at different mixing ratios and temperatures. The effect of air humidity was also investigated. Complex ion chemistry is observed as a result of the interplay of several different reagent ions, including atmospheric ions O(2)(+*), NO(+), H(3)O(+), and their hydrates, but also alkyl fragment ions derived from the alkanes. Some of these reactions are known from previous selected ion/molecule reaction studies; others are so far unreported. The major ion formed from most alkanes (M) is the species [M - H](+), which is accompanied by M(+*) only in the case of n-octane. Ionic fragments of C(n)H(2n+1)(+) composition are also observed, particularly with branched alkanes: the relative abundance of such fragments with respect to that of [M - H](+) decreases with increasing concentration of M, thus suggesting that they react with M via hydride abstraction. The branched C(7) and C(8) alkanes react with NO(+) to form a C(4)H(10)NO(+) ion product, which upon collisional activation dissociates via HNO elimination. The structure of t-Bu(+)(HNO) is proposed for such species, which is reasonably formed from the original NO(+)(M) ion/molecule complex via hydride transfer and olefin elimination. Finally, linear alkanes C(5)-C(8) give a product ion corresponding to C(4)H(7)(+)(M), which we suggest is attributed to addition of [M - H](+) to C(4)H(8) olefin formed in the charge-transfer-induced fragmentation of M. The results are relevant to applications of nonthermal plasma processes in the fields of air depuration and combustion enhancement.
|
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:status |
PubMed-not-MEDLINE
|
| pubmed:month |
Apr
|
| pubmed:issn |
1879-1123
|
| pubmed:author | |
| pubmed:issnType |
Electronic
|
| pubmed:volume |
20
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
697-707
|
| pubmed:year |
2009
|
| pubmed:articleTitle |
A mass spectrometry study of alkanes in air plasma at atmospheric pressure.
|
| pubmed:affiliation |
Dipartimento di Scienze Chimiche, Università di Padova, Padova, Italy.
|
| pubmed:publicationType |
Journal Article
|