“…Trace element contents in bauxites have been determined by a variety of methods including instrumental neutron activation analysis (INAA) (Vukoti c 1983, Korotev 1996, Grant et al 2005), X-ray fluorescence spectrometry (XRF) (Mordberg et al 2001) and inductively coupled plasma-atomic emission spectrometry (ICP-AES) (Boulang e andColin 1994, Ochsenk€ uhn-Petropoulou et al 1990). In recent years, inductively coupled plasma-mass spectrometry (ICP-MS) has become the technique of choice because it allows the determination of a comprehensive set of elements that includes transition metals, high field-strength elements (HFSE) and rare earth elements (REE) at low mass fractions (e.g., Horbe and Anand 2011, Gu et al 2013, Wang et al 2013, da Costa et al 2014, Mongelli et al 2014, Ahmadnejad et al 2017). However, a key concern in obtaining reliable trace element mass fractions by solution ICP-MS is the difficulty in achieving complete digestion of the bauxite, as it often contains refractory minerals such as zircon, anatase/rutile, monazite, xenotime, titanite, thorite and tourmaline (B ardossy and Aleva 1990, Horbe and Da Costa 1999, da Costa et al 2014, Monsels and Van Bergen 2017a.…”