Operating manual for the Marianda (Versatile INstrument for the Determination of Titration Alkalinity) VINDTA 3C for the laboratory based determination of Total Alkalinity and Total Dissolved Inorganic Carbon in seawater

All chemical and biogeochemical process in the sea are affected by the acidity of the water. Acidity is therefore fundamental property of seawater. The growing concern that the acidity of the oceans might be increasing has revealed weaknesses in our knowledge of this fundamental property and its variation in space and time. In 2008 the DEFRApH project (DEFRA contract ME4133) was initiated to provide this missing information in UK related waters. It required sampling for and analysis of the total inorganic carbon (DIC) and total alkalinity (TA) content of samples. This report documents the procedures used for operation of the VINDTA 3C analysis instrument (manufactured by Ludger Mintrop, Marianda, Kiel, Germany) developed at NOC since 2005. It covers instrument set up, daily procedures and the calculation of the final reported concentrations.