Simon Clegg has just completed a visit of two and a half months to the University of Gothenburg, Sweden, where he worked with WG 145 Chair David Turner. Experimental work needed for the development of the chemical speciation model was planned, and the current “state of the science” Pitzer model of artificial seawater was assembled and the parameters checked. Our initial goal is to develop a metrologically traceable model of Tris/TrisH+ buffers in artificial seawaters, as a function of both salintiy and temperature. The planned experiments reflect this, and include solutions such as Tris/TrisH+ in NaCl(aq), H+/TrisH+/Cl- solutions, and Tris/TrisH+ in aqueous NaCl/Na2SO4, for example.
The large experimental effort will be shared between Andrew Dickson at Scripps Institution of Oceanography, and our colleagues at the national metrological institutes of Germany, France, and Japan, and at GEOMAR in Kiel (Germany).