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Fossil weevil
a
C3
C4
C1
C2
P2
Py
15
P1
19
P
1
7
21
23
*
B3
25
B
2
B4
27
I
29
31
33
b
13
15
17
23
19
21
28
16
m/z
74+87
14
18
6
22
10
26
Retention time
Fig. 4.7
(
a
) Partial py-GC-MS total ion current chromatogram of fossil weevil showing the pres-
ence of n-alkane, n-alk-1-ene homologues, number indicating the carbon chain length, together
with benzene derivatives (peak labels same as in Fig.
4.4
). Chitin markers.
C1
: acetylpyridone,
C2
:
3-acetamidofuran,
C3
: 3-acetamido-5-methylfuran,
C4
: 3-acetamido-4-pyone.
I
: methyl indole,
Py
: C1-pyrrole. *Contaminant. (
b
) Partial TMAH/Py-GC-MS total ion current chromatogram of
fossil weevil. n-alkane, n-alk-1-ene homologues, number indicating the carbon chain length. The
m/z 74 + 87 mass chromatogram reveals the distribution of constituent fatty acid methyl esters,
FAME (d); C16 followed by C14 are the most abundant (cf. Fig.
4.8
, thermochemolysis of associ-
ated sediment, where the acid distributions are different)
The total organic content of the sediment associated with the weevil is
exceptionally high (23.6). Pyrolysis (Fig.
4.8a
) released
n
-alkane/
n
-alk-1-ene
homologues ranging in carbon number from C
9
to C
30
. The most abundant
n
-alkanes
have carbon chain lengths of C
15
, C
21
and C
13
(Table
4.1
) and the most abundant
n
-alk-1-enes have carbon chain lengths of C
16
, C
21
and C
22
. Alkyl benzenes from C
2
to C
4
are also abundant in the pyrolysate but no polysaccharide, protein or lignin
moieties were released by pyrolysis, consistent with previous results from the same
site (Stankiewicz et al.
1997a
). Thermochemolysis of the sediment (Fig.
4.8b
)
generated FAME ranging in carbon number from C
6
to C
28
. The long-chain FAME,
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