Iron

For the iron chemistry project, seawater samples are collected during our annual relief voyages to Antarctica on board RV Agulhas II. A GEOTRACES trace metal clean 24 x 12L GoFlo carousel and Kevlar cable winch (Figure 1) is used to collect seawater along a vertical profile. Subsampling is conducted inside a certified trace metal clean container lab equipped with circulating HEPA filters for clean air supply (Figures 2 and 3). Concentrations for total dissolvable Fe (TDFe, unfiltered), dissolved Fe (DFe, filtered through 0.22 µm) and soluble Fe (SFe, filtered through 0.02µm) are measured using a Flow Injection Analyser (FIA; Figures 3 and 4) with chemiluminescence detection inside a trace metal clean class 100 laboratory at Stellenbosch University. An ICP-MS is also available at Stellenbosch University.

Seawater samples are also collected from the GoFlo bottles for the incubation experiments (Figure 6). Phytoplankton physiological parameters are measured using a Chelsea Fast Repetition fluorimeter (FRRf; Figure 4), dissolved Fe using the dedicated FIA in the trace metal clean laboratory at Stellenbosch University, and macro-nutrients using FIA at CSIR. The culture experiments are also conducted inside the trace metal clean class 1000 laboratory at Stellenbosch University

  • Figure 4: Dr. Thato Mtshali setting up the Fast Repetition Rate Fluorometer (FRRf) inside a trace metal clean laboratory container.
  • Figure 2: Dr. Thato Mtshali setting up the FIA system inside a trace metal clean laboratory container for Fe concentration measurements in seawater during field work at sea.
  • Figure 3: Prof Alakendra Roychoudhury and Natasha van Horsten inside a trace metal clean laboratory at SUN, showing the Flow Injection Analyzer for measuring Fe concentration in seawater on land (photo credit: Wiida Fourie-Basson, Stellenbosch University).
  • Figure 1: Trace metal GEOTRACES CTD rosette equipped with 24 12L GoFlo bottles.
  • Figure 5: Dr. Thato Mtshali holding certified certificates for two trace metal clean container laboratories.
  • Figure 6: Three incubators for growing phytoplankton community at sea under different dFe supply and light regimes (Bioassay experiments).
Related News and Publications

For the iron chemistry project, seawater samples are collected during our annual relief voyages to Antarctica on board RV Agulhas II. A GEOTRACES trace metal clean 24 x 12L GoFlo carousel and Kevlar cable winch (Figure 1) is used to collect seawater along a vertical profile. Subsampling is conducted inside a certified trace metal clean container lab equipped with circulating HEPA filters for clean air supply (Figures 2 and 3). Concentrations for total dissolvable Fe (TDFe, unfiltered), dissolved Fe (DFe, filtered through 0.22 µm) and soluble Fe (SFe, filtered through 0.02µm) are measured using a Flow Injection Analyser (FIA; Figures 3 and 4) with chemiluminescence detection inside a trace metal clean class 100 laboratory at Stellenbosch University. An ICP-MS is also available at Stellenbosch University.

Seawater samples are also collected from the GoFlo bottles for the incubation experiments (Figure 6). Phytoplankton physiological parameters are measured using a Chelsea Fast Repetition fluorimeter (FRRf; Figure 4), dissolved Fe using the dedicated FIA in the trace metal clean laboratory at Stellenbosch University, and macro-nutrients using FIA at CSIR. The culture experiments are also conducted inside the trace metal clean class 1000 laboratory at Stellenbosch University

'