Geology Reference
In-Depth Information
a
Pandinus emperator cuticle
6
5
f
h
d
e
g
1
10
11
15
2
a
7
12
9
h
6
8
16
b
13 14
c
3 4
b
Limulus polyphemus cuticle
Protein
6
Catechol
CH 2 OH
OH
HN
+
N
O
O
O
OH
Chitin
CH2
5
CH2
NH
C=O
C=O
f
e
h
h
1
R
CH 3
8
g
7
2
12
10
3
14
16
c
Limulus polyphemus
C 16 FA
o
o
Methylated chitin/ protein products and
short chain acids
C 18 FA
o
o
o
Retention time
Fig. 7.2 Py-GC-MS analysis of modern scorpion and Limulus cuticles. ( a ) Partial Py-GC-MS
chromatogram of modern Pandinus imperator cuticle revealing the presence of chitin or protein
and cuticular lipids. ( b ) Partial Py-GC-MS chromatogram of Limulus cuticle revealing the same,
with the inset showing the chemical structure of arthropod cuticle (adapted from Stankiewicz et al.
1996 ). ( c ) Partial TMAH pyrolysis (thermochemolysis)-GC/MS chromatogram of Limulus cuticle
revealing the distribution of fatty acyl moieties (o). Note difference in retention time of the acids
during thermochemolysis (Fig. 7.2c ) compared to that from pyrolysis (Fig. 7.2a ) due to methyla-
tion reactions. Retention time in Fig. 7.2a b and are different because of different GC programs
used. For key to annotations see Table 7.2
 
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