Recent Advances in Gallium Isotope Analysis for Geological Materials using Multi-collector ICP-MS

Gallium isotopes are a promising tool in geology and planetary science, with MC-ICP-MS enabling highprecision measurement of Ga isotopic composition.Samples are purified to remove interfering elements using two double-column and three triple-column methods, all achieving over 95% recovery with excellent reproducibility.The Neptune MC-ICP-MS, coupled with an Apex gas introduction system, achieves the highest sensitivity and requires the smallest sample consumption (80 ng Ga).The C-SSBIN method-combining sample-standard bracketing with Cu as an internal standard-delivers the highest precision and long-term stability.Two Ga isotope reference standards are available, with the solid NIST 994 standard exhibiting isotopic heterogeneity.The IPGP Ga solution demonstrates superior stability and more closely approximates natural Ga isotopic compositions, making it the preferred Ga isotope reference standard.High-precision Ga isotope measurements by MC-ICP-MS provide valuable insights for advancing Ga isotope fractionation theory and expanding its geological applications.Neptune Glass spray chamber Wet plasma 200 g/L 7 V <1 mV GPMR Wuhan (China) Zhang et al. (2016) 8 Neptune Apex Dry plasma 25 g/L 7-9 V Not clear IPGP (France) Kato et al. (2017) 16 Neptune Glass spray chamber Wet plasma 100 g/L 4.5 V Not clear CUGB (China) Li et al. (2025) 34 Neptune Glass spray chamber Wet plasma 100 g/L 4.7 V <0.1 mV GPMR Wuhan (China) Feng et al. (2019) 22 Neptune Glass spray chamber Wet plasma 40 g/L 2.5 V Not clear LLNL (USA) Wimpenny et al. (2020) 11 Neptune Glass spray chamber Wet plasma 200 g/L Not clear <0.5 mV IGCAS Guiyang (China) Zhang et al. (2021) 23 Nu Plasma II Aridus II Dry plasma 50 g/L 7 V <1 mV IGCAS Guiyang (China) Yuan et al. (2016) 15 Neptune Apex Dry plasma 20 g/L 8 V <1 mV IGCAS Guiyang (China) Yuan et al. (2016) 15 Nu Plasma II Apex Dry plasma 50 g/L Note clear Not clear