Geology Reference
In-Depth Information
a
Chitin
14
10
1
7
15
12
2
6
8
13
5
11
3
9
4
16
b
Untreated cockroach cuticle
C
18:1
FA
Pr
3
Pr
4
C
16
FA
14
Pr
2
16
C
16:1
FA
C
18
FA
Pr
1
15
Pr
6
Pr
5
11
16
Retention time
Fig. 8.1
Partial pyrolysis-GC/MS chromatograms of (
a
) pure chitin and (
b
) cockroach cuticle
.
1
: pyridine;
2
: methyl pyridine;
3
: acetamide;
4
: 3-hydroxy-2-pyridone;
5
: 2-pyridine carboxalde-
hyde;
6
: acetylpyrrole;
7
: acetylpyrroline;
8
: amine derivative;
9
: levoglucosenone;
10
: unknown;
11
: acetyldihydropyridine;
12
: acetylpyridone;
13
: 3-acetamidofuran;
14
: 3-acetamido-5-
methylfuran;
15
: 3-acetamido-4-pyrone;
16
: oxazoline structures;
Pr
1
: methyl pyrrole,
Pr
2
: phenol,
Pr
3
: unknown,
Pr
4
: indole,
Pr
5
: methylindole,
Pr
6
: diketopiperazines,
CnFA
: fatty acyl moieties,
where n refers to the carbon chain length and n:1 denotes mono-unsaturation in the alkyl chain. No
n
-alkanes/alkenes were detected. The analysis time was 55 min
The pyrolysates of the untreated cockroach cuticle (Fig.
8.1b
) contain these chitin
markers but also protein pyrolysis products (see Stankiewicz et al.
1997a
for identi-
fi cation and mass spectral characteristics). The straight chain fatty acids
n-
C
16
and
n
-C
18
(both saturated and unsaturated components) were also observed in the cuticle
pyrolysates (and were also detected in modern stingless bee cuticle: Stankiewicz
et al.
1998b
). No alkane/alkene homologues were detected. The modern scorpion
and shrimp cuticle pyrolysates were similar to that of the cockroach cuticle (traces
not shown).
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