Case studies of arsenic in hydrothermal fluids of three different regimes: Menez Gwen (MAR), Manus Basin, and Panarea (Äolian Island-arc)

Three different preservation methods were tested by adding HCl to increase solubility of iron (Fe) and manganese (Mn) and EDTA to complex these two to prevent the arsenic (As) from precipitation as As-sulfides like arsenopyrite (FeAsS). As this would cause As to be underestimated and speciation to change. Another aliquot was preserved without chemical additives but immediately frozen. All three aliquots were stored and transported frozen.