The data in this doi belong to:
Comparing CLE-AdCSV applications using SA and TAC to determine the Fe binding characteristics of model ligands in seawater 
Gerringa, L.J.A.1*, Gledhill, M.2, Ardiningsih, I.1, Muntjewerf, N.1, Laglera, L.M.3
	Royal Netherlands Institute for Sea Research (NIOZ), Department of Ocean Systems, Texel, the Netherlands.  

	GEOMAR Helmholtz Centre for Ocean Research, 24148 Kiel, Germany.

	FI-TRACE, Departamento de Química and ‡Laboratori Interdisciplinari sobre Canvi Climàtic, Universidad de las Islas Baleares, Palma, Balearic Islands 07122, Spain.
 

Folder: calculation titrations
The sensitivity, S, the ligand concentration [L] and conditional stability constant (K^cond) were calculated by direct non-linear fitting of the Langmuir isotherm (Gerringa et al., 2014) with inherent co-dependence of [L] and  K^cond
A choice has to be made running the program between applications: name of AL, concentration of AL and inorganic alpha belonging to the specific pH, 8.05 or 8.2. See below # means not active. The below copied text is activated for TAC at 10 µM at pH=8.05.
#alphaLig = "SA5_Fe"
#alphaLig = "SA25_Fe"
alphaLig = "TAC_Fe"

#CLig = 5*10^-6	
#CLig = 25*10^-6
CLig = 10*10^-6 

alphaMe = 10^9.9
#alphaMe = 10^10.4

Input file calculations: In the file names the addition to be done to the result [L] is added in the name. This concentration is the Fe concentration of the AL at the concentration used.
Output:  Be aware that in the figures of the fit, sensitivity (S) manual is not defined separately per sample, since the calculation went automatically. However, manual S is not used for calculating the linearizations. Here also the automatic S is used.
 
Excel file : data figures compilation
The excel file containing the data of the figures, has per figure a sheet the figure captions follow below:
Figure 1: Iron titrations of UV irradiated seawater containing model ligands in competition with TAC, SA5, and SA25 as added ligand. [FeAL] = Fe-added ligand complex using sensitivity (S)=1, [Fe] = total iron concentration. See Table 2 of the paper for the DFe at zero addition.
A=DTPA, B=phytic acid, C=desferrioxamine B, D=ferrichrome, E=ferrioxamine E (saturated with Fe), F=vibriobactin, G=fulvic acid FA, H=humic acid HA
Data for TAC and SA5 are from duplicate experiments, for SA25 from single experiments, except for FA and HA where for SA25 also duplicate experiments were done.

Figure 2: Iron titrations of UV irradiated seawater containing model ligands in competition with TAC, SA5, and SA25 as added ligand, [FeAL] versus total dissolved Fe. The same data as in Figure 1 is presented but with a log - log transformation. The lines represent back calculated titration curves with the data from Table 2, the markers are the actual data points. The blue lines in 2A and D, are back calculated titration curves using theoretical K^cond calculated from the thermodynamic constants and 2 nM as model ligand concentration.
A=DTPA, B=phytic acid, C=desferrioxamine B, D=ferrichrome, E=ferrioxamine E (saturated with Fe), F=vibriobactin, G=fulvic acid FA, H=humic acid HA.
Data for TAC and SA5 are from duplicate experiments, for SA25 from single experiments, except for FA and HA where for SA25 also duplicate experiments were done.

Figure 3: In-cell kinetic experiments, with the three AL applications, in UV irradiated seawater, UV irradiated seawater + DTPA (200 nM for TAC and 40 nM for the SA25 application) and natural seawater.  For SA25 UV and UV+40 nM DTPA was done. At t=0 AL is added. A: TAC, B: SA25

Figure 4. In-cell kinetic experiments at different [SA], peak heights versus time. Measurements versus time are done in the same 10ml, using the Metrohm electrode; drop size =1, with regular purging with air. 
At t=0 SA was added.

Figure 5: Reversibility of Fe-SA formation upon addition of 150 nM DTPA at t=80 minutes.
The experiment was undertaken with a Metrohm electrode in-cell in UV irradiated seawater with 6 nM Fe and two SA concentrations, 5 µM SA (right hand side Y axis) and 15 µM SA (left hand side Y axis).

Figure 6: Kinetic measurements for the formation of Fe-SA complexes, the change in peak height versus time. At t=0 the AL is added.
In-cell means the whole experiment is done in the same 10 ml which was placed in the cell, dispensed mercury accumulates at the bottom of the cell. Bottle experiment means for every measurement a fresh 10 ml was taken from a large volume of sample. Here the reaction takes place in the large volume, and AL was added at t=0.
A and B: UV irradiated sea water (UV); C and D: UV+desferrioxamine B; E and F: UV+phytic acid bottle (A, C, E) and in-cell experiments (B, D, F) are shown. G: For FA only bottle experiments were done with SA5 and SA25 as AL

Supplementary information.
Figure S1: Kinetic experiment with SA25, using the Metrohm setup. Added DFe=7 nM. Every color is a separate sub-sample in a conditioned vial, all vials had the same t=0, where SA was added. The first measurements can be called in-cell. Upon changing samples tiny shifts occurred, which might be due to changes in DFe and contamination while changing the sample. Before every measurement the sample in the cell is purged with air, but pulses of nitrogen are introduced in the overhead of the cell when drops are formed. However, the decrease in signal with time is clear and does not seem to be influenced by prolonged in-cell measurements due to pulses of nitrogen gas upon drop formation.
Standard additions were done at the end of the experiment on the kept samples and concentrations were calculated from peak heights.

Figure S2: Measurements using SA5 and SA25 in UV irradiated seawater with 6 nM DFe of FeAL with time (s) with and without a purge step in both setups, A: Metrohm, B: BASi. The data is in % of the first recorded peak height. Drop size 1 for Metrohm, size 10 for BASi. 

Figure S3: The effect of drop size and accumulation of drops at the bottom of the measuring cup. The reduction in peak size over time might be due to adsorption of the electro active Fe complex on the puddle of dispensed mercury formed in time on the bottom of the cell.
S2A,B,C: Peak height versus time for different drop sizes in UV irradiated seawater with 6 nM added Fe. A: Metrohm, SA5 and SA25, drop sizes 1 and 3 (Table S3), B and C: BASi drop sizes 5,10 and 14 (Table S3), B gives SA5 data, C gives SA25 data. The last recorded peak t=end per experiments is set as 1, the other peak heights are related by division trough the peak at t=end. T=end is approximately 1 hour for the Metrohm, and 43 minutes for the BASi equipment. Experiment SA5 with drop size 5 at BASi was done in duplicate.
S2D: peak height reduction in 43 minutes, versus the volume of dispensed mercury at the bottom of the cell at t=43. Metrohm hardly showed any difference between SA5 and SA25

Figure S4: Calibration of the three applications (A, TAC, B, SA5, C, SA25) with DTPA. The calibrations were repeated 4 times indicated by the different colors. X is the peak height divided by the peak height at zero DTPA.

Figure S5: The percentage error (E%) of the estimated ligand concentration per AL [LAL] compared to the added concentration []: E(%) = ((LAL-[])/[])x100) for each synthetic model A.
1,2=DTPA; 3,4=phytic acid; 5,6= desferrioxamine B, 7.8=Ferrichrome, 9,10=2nM Ferrioxamine E; 11,12=4nM Ferrioxamine E; 13,14=vibriobactin.

Figure S6: Figure S6: In cell kinetic experiments with the TAC application for different model ligands added at 2nM for the model A ligands and 0.2 mg for the model B ligand (FA).