Variability in biomass and structure of phytoplankton populations in the Canary Islands waters, as d

1
(No Transcript)
2
4 Extraction (is methanol really the best
option?)
2
3
May cause peak distortion
4 Extraction (is methanol really the best
option?)
3
4
Dilute sample with water risky!
4
5
Solvent- and time dependant losses of individual
compounds 1 Maximum sample dilution
permitted 2 Best solvent for storage
and injection
Dilute sample with water
5
6
6
7
7
8
8
9
Deviations ? 5 were attributed to equipment and
sample treatment
9
10
10
11
Emiliania huxleyi extracted in acetone, diluted
with water
11
12
Emiliania huxleyi extracted in acetone, diluted
with water
12
13
13
14
14
15
Dunaliella tertiolecta extracted in acetone,
diluted with water
15
16
Dunaliella tertiolecta extracted in acetone,
diluted with water
16
17
17
18
18
19
Dunaliella tertiolecta extracted in methanol,
diluted with water
19
20
Dunaliella tertiolecta extracted in methanol,
diluted with water
20
21
21
22
22
23
Emiliania huxleyi extracted in methanol, diluted
with water
23
24
Emiliania huxleyi extracted in methanol, diluted
with water
24
25
(No Transcript)
26
Recommendations 1 The established limits of
the safe dilution rates are critical and
seawater volumes retained by the filters are thus
very important. Individuals should check
their own limits for which they may
(initially) employ a spectrophotometric
approach. 2 An HPLC setup should preferably
include a refrigerated auto- injector capable
of sample dilution prior to injection. 3 In
this case it is safe to use a final concentration
of 80 - 90 acetone for sample storage at
4ºC (reliable up to at least 48 h), diluted
to 70 before injection (maximum injection volume
in HPLC without risk of pigment losses at
t0).
27
(No Transcript)