Trace metal distribution in the water column along 40°S

Christian Schlosser, Jessica Klar, Ebby Desai, and Eric Achterberg

National Oceanography Centre Southampton

Cruise Track and Sampling Positions UK GEOTRACES 40°S

RRS James Cook JC068 (Dec. 2011 - Jan. 2012)• 15 Ti casts (full depth)• 2 Ti cast (1000m)• ~150 surface sites Trace Metal Sampling

• Ti rosette frame with trace metal clean OTE bottles and self-triggering bottle closure system

• Fish

Analysis• Dissolved and total dissolvable Fe, Cd, Pb, Cu, Ni, (Zn) by ID-ICP-MS

• Dissolved and total dissolvable Ag, Mn (Co) by standard addition ICP-MS

• Dissolved and total dissolvable Al by flow injection fluorescence (Brown and Bruland, 2008)

3

• 12 ml sample• Spiked with isotope mixture• Standard addition for mono-isotopic elements

(Co, Mn)• UV digestion• Chelating resin WAKO• 1 ml elution with 1.5 M HNO3

• Measured on XR Element II HR ICPMS

- 100 µl isotope mix- Standard addition Co/Mn- Buffer

1.5 M HNO3

Preconcentration for Multi Element Analysis

4

• 20 ml sample• Standard addition• 1 day equilibration• Dowex anion exchange resin • 2 ml elution with 1.5 M HNO3

• Measured on XSeries ICPMS

- Standard addition Ag

1.5 M HNO3

Preconcentration for Ag

Preliminary Results

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Ag (pmol L-1)

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Ag (pmol L-1)

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Ag (pmol L-1)

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Ag (pmol L-1)

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Sta. 20 Sta. 13 Sta. 11

Work in Progress

• Multi trace element analysis of surface and subsurface samples from JC068 and D357 by isotope dilution/standard Addition ICP-MS (end of October this year)

• Fe ligand analysis (beginning of next year)

• Fluorescence dissolved organic matter (FDOM) (beginning of next year)

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Preconcentration

• Chelating resin WAKO (similar to NOBIAS Chelate PA1)• methacrylate resin• carboxymethylated pentaethylenehexamine (CM-PEHA resin)• Excellent Mn measurements: stable Mn calibration slopes

• Kagaya et al., Talanta 2009, 79: 146-152