Parameters   Radio frequency power 1550 W Sample depth 10.0 mm Plasma flow rate 15 L/min Nebulizer gas flow rate 1.09 L/min Nebulizer pump 0.10 rps Spray chamber Scott (double pass) at 2°C Interface Platinum cones Sampling cone 1 mm Skimmer 0.4 mm Resolution 1.5       u Selected isotopes for analytes 27Al+, 51V+, 52Cr+, 55Mn+, 56Fe+, 56Co+, 60Ni+, 63Cu+, 68Zn+, 75As+, 80Se+, 88Sr+ and 137Ba+ On line internal standard 72Ge (250 µg L-1 diluted on line 20 x ) ORS3 * Collision Gas flow He Mode HEHe Mode                 4.3 mL/min                              10 mL/min Energy discrimination 3.0 V 7.0 V * ORS3: Octapole collision/reaction system third generation

Table 1: Operating conditions used in the ICP-MS.