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Alkene Triplet Pattern

Definition

The GC-MS signature of polypropylene pyrolysis: a repeating triplet of n-alkane, 1-alkene (terminal double bond), and diene peaks at each carbon number from C5 to C15, visible in the TIC and confirmed by elevated m/z 55 (alkene fragment) in the extracted ion profile.

Related terms

4-Vinylcyclohexene (4-VCH)
A pyrolysis product of styrene-butadiene rubber (SBR) carpet backing, appearing at m/z 108 in the GC-MS. Elevated m/z 108 in a fire...
Background Subtraction
The analytical practice of comparing fire debris EIPs against comparison sample EIPs from unburned substrate of the same type. Features present in...
Comparison (Control) Sample
A sample of unburned substrate collected from the same room or proximate unburned area as the fire debris sample, of the same...
Principal Component Analysis (PCA)
A multivariate statistical method used in fire debris research to reduce chromatographic data matrices to principal components that capture major variance. Used...
Pyrolysis
The thermal decomposition of cellulose in paper at approximately 150 to 300 degrees Celsius, disrupting glycosidic bonds and releasing water and carbon...
Substrate Interferent
A pyrolysis product from building or furnishing material that produces a GC-MS chromatographic pattern overlapping with or resembling an ignitable liquid category...
SWGFEX Type C Interferent List
A documented list maintained by the Scientific Working Group for Fire and Explosion Investigation (and continued by OSAC) of substrates known to...
Type C Interferent (E1618)
ASTM E1618 designation for a substrate whose pyrolysis products can produce a chromatographic pattern meeting the criteria for an ignitable liquid category....
Unresolved Complex Mixture (UCM)
The broad hump of hundreds of co-eluting cycloalkane and isoalkane compounds in the TIC of heavy petroleum products (diesel, heavy fuel oil,...

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