332
0.016
i
0.012
~ 0.008
c::
~ III
.0 0.004
cC
0.0
2.0
100 m/z3oo
~
75
oJ
50
.5
J! 25
100 m/z316
~
75
oJ
50
.5
£ 25
100 m/z396
~
75
oJ
50
.5
Qj
a:
25
0.0
2.0
4.0
4.0
STX
6.0
TIme (min)
GTX2
NEO
6.0
8.0
M. Vincenti . A. Irico
a
8.0
10.0
b
c
d
10.0
12.0
Fig. 17.8. Analysis of saxitoxin mixture isolated from a culture of the dinoflagellate Alexandrium
excavatum by capillary electrophoresis (CE); a CE-UV at 200 nm; b,c,d selected ion mass chromatograms
from CE-ESI-MS (reprinted with permission from Pleasance et al.1992a)
weight fell beyond the mass range of the instrument used. The detection of several
doubly and triply charged ionic species, such as [M + 2 H + Na]3+, [M + 2 H + K]3+,
[M + H + Naf+, [M + 2 H + K]2+, giving signals at m/z values equal to one third and
one half of their mass, allowed easy deduction of maitotoxin molecular weights (Lewis
et al. 1994).
0.016
i
0.012
~ 0.008
c::
~ III
.0 0.004
cC
0.0
2.0
100 m/z3oo
~
75
oJ
50
.5
J! 25
100 m/z316
~
75
oJ
50
.5
£ 25
100 m/z396
~
75
oJ
50
.5
Qj
a:
25
0.0
2.0
4.0
4.0
STX
6.0
TIme (min)
GTX2
NEO
6.0
8.0
M. Vincenti . A. Irico
a
8.0
10.0
b
c
d
10.0
12.0
Fig. 17.8. Analysis of saxitoxin mixture isolated from a culture of the dinoflagellate Alexandrium
excavatum by capillary electrophoresis (CE); a CE-UV at 200 nm; b,c,d selected ion mass chromatograms
from CE-ESI-MS (reprinted with permission from Pleasance et al.1992a)
weight fell beyond the mass range of the instrument used. The detection of several
doubly and triply charged ionic species, such as [M + 2 H + Na]3+, [M + 2 H + K]3+,
[M + H + Naf+, [M + 2 H + K]2+, giving signals at m/z values equal to one third and
one half of their mass, allowed easy deduction of maitotoxin molecular weights (Lewis
et al. 1994).