7900 icp qms

An aliquot of each acid-dissolved angrite sample was used for elemental concentration measurements with an Agilent 7900 ICP-QMS housed at the IPGP. Another aliquot of the same powdered angrite sample was dissolved using alkali hydroxides to measure Si contents on this instrument. Elemental concentrations were measured in low-resolution mode. Sample solutions were aspirated into a Scott spray chamber using a MicroMist micro-nebulizer (uptake rate = 0.2 mL/min). Elements with atomic masses between 23 (Na) and 75 (As) were measured using a collision-reaction cell supplied with He gas (5 mL/min) to remove polyatomic interferences. Scandium, In, and Re were used as internal standards to correct for signal drift and matrix effects. Count measurements were converted to solution concentrations by analyzing a mixture of certified standards with concentrations spanning the range of the samples. Data are reported in Supplementary Tables 1 and 2.

Elemental concentrations of filtered and acidified groundwater were characterized at low resolution using an Agilent 7900 ICP-QMS in pulse counting mode. Sample introduction was achieved with a micro nebulizer (Micro Mist, 0.2 ml min⁻¹) through a Scott spray chamber. All elements were measured using a collision reaction interface with helium gas (5 ml min⁻¹) to remove isobaric interferences.