Al, Fe and Si contents of the dissolved NaOH fusions were analyzed by ICP-OES (Varian 725-ES) with Europium as the internal standard. For Ge measurements, the dissolved NaOH fusions were dried and re-dissolved in 1% v/v HNO3 with 10 ppb indium (In) for analysis by HR-ICP-MS (Element 2) in medium
resolution.