PROSOPE |
|
H. CLAUSTRE : head of mission and project leader |
IRON : C. Ridame, C. Guieu |
| Iron Analysis | Read DATA Set |
Responsible person: Cécile Guieu (LPCM, Villefranche-sur-Mer)
Other scientist involved: Stéphane Blain (IEUM, UBO, Brest), Yann Bozec, Céline Ridame
Tel.: 33 0-4 93 76 37 24; fax.: 33 0-4 93 76 37 39
e-mail : guieu@obs-vlfr.fr
Total dissolved iron (<0.4µm) was analyzed along the vertical profiles at stations UPW, MIO and DYF on filtered samples collected (1) by pumping (depth 0-200m) and (2) by Niskin bottles (depth>200m). Samples were also collected by pumping (5m and 10m) during the short stations along the transect. Special care was observed during the sampling to avoid any contamination (filtration on-line inside a clean container of the pumped samples; use of a kevlar cable for the pumping system etc.). Only few samples were obviously contaminated.
The filtered samples were acidified on board and iron was measured in the laboratory. The method is based on column extraction and chemiluminescence detection in a closed flowthrough system : Fe(III) in the acidified sample solution is selectively collected on 8-hydroxy-quinolinol immobilized chelating resin and then eluted with hydrochloric acid. The resulting eluent is mixed with luminol solution, aqueous ammonia, and hydrogen peroxide solution successively, and then the mixture is introduced into the chemiluminescence cell. The iron concentration is proportional to the chemiluminescence intensity. (the method is fully described in Obata et al. 1993).
Reference.
Obata H., Karatani H. and Nakayama E., 1993, Automated determination of iron in seawater by chelating resin concentration and chemiluminescence detection, Analytical Chemistry, 65, 11: 1524-1528.
These data are validated. However, the data mentioned (*) are suspected to be issued from a contaminated sample.
CTD_pressure : from CTD_Bottle_Table updated october 2000
STATION UPW
N° bottle CTD
ctd-press(dba)
depth dba
conc. Fe nM
pumping
5
1,79
CTD 011
20
4.739
5
1,68
CTD 011
18
11.251
11
0,93
CTD 011
16
20.682
20
0,99
CTD 011
14
29.526
29
0,75
CTD 011
12
38.585
38
0,82
CTD 011
10
49.269
49
0,96
CTD 011
8
59.277
59
1,29
CTD 011
6
80.723
80
1,92
CTD 011
4
100.680
100
1,25
STATION MIO
N° bottle CTD
ctd-press(dba)
depth dba
conc. Fe nM
pumping
5
1,46
pumping
10
1,99
pumping
24,1
0,59
pumping
50
0,61
pumping
75
0,42
pumping
101,6
0,26
pumping
123,6
0,28
pumping
144,6
0,36
pumping
175
13.5*
pumping
188,4
1,08
CTD 062
20
199.077
200
0,78
CTD 062
16
449.979
450
0,59
CTD 062
10
999.615
1000
0,13
CTD 062
2
1999.895
2000
0,33
STATION DYFAMED
N° bottle CTD
ctd-press(dba)
depth dba
conc. Fe nM
pumping
5
1,42
pumping
9
1,23
pumping
20
3,10
pumping
40
0,45
pumping
72,6
0,47
pumping
98,6
0,39
pumping
123,6
0,60
pumping
150
0,62
pumping
173
0,51
pumping
193
0,57
CTD 108
20
199.725
200
3.5*
CTD 108
16
450.228
450
1,08
CTD 108
10
998.556
1000
1,06
CTD 108
4
2000.415
2000
0,52
SHORT STATIONS 2
depth dba
conc. Fe nM
pumping
4,8
1,35
pumping
4,8
0,99
pumping
10,1
0,69
pumping
10,1
0,71
SHORT STATIONS 3
depth dba
conc. Fe nM
pumping
5
1,02
pumping
5
1,16
pumping
10,1
0,94
pumping
10,1
0,91
SHORT STATIONS 4
depth dba
conc. Fe nM
pumping
5
1,80
pumping
5
1,77
pumping
10
2,08
pumping
10
1,78
SHORT STATIONS 5
depth dba
conc. Fe nM
pumping
5
2,40
pumping
5
2,78
pumping
10,1
2,10
pumping
10,1
1,90
SHORT STATIONS 6
depth dba
conc. Fe nM
pumping
5
1,67
pumping
5
1,41
pumping
10
2,09
pumping
10
1,90
SHORT STATIONS 7
depth dba
conc. Fe nM
pumping
5,3
1,83
pumping
5,3
1,7
pumping
10,7
2,75
pumping
10,7
2,69
SHORT STATIONS 8
depth dba
conc. Fe nM
pumping
10
2,48
pumping
10
2,6
pumping
5
1,41
pumping
5
1,78
SHORT STATIONS 9
depth dba
conc. Fe nM
pumping
5
1,43
pumping
5
1,56
pumping
10
3,01
pumping
10
2,6