Electrodeposition and characterization of Sn on Re filaments for laser resonance ionization mass spectrometry

The isotopic analysis of Sn is crucial for geochemical research and surveillance of nuclear contamination. However, commonly used methods face the challenge of isobaric interference. Laser resonance ionization mass spectrometry (LRIMS) is a promising technology for effectively eliminating the isobaric interference effect as it combines the advantages of both resonance ionization and mass spectrometry technologies. In this study, an atomic source of 1 μg Sn was prepared by electrodeposition on a Re filament in a 1-5 × 0.7 mm spot for LRIMS measurement. The effects of voltage, duration, length of the active area, and Pb content on the deposition yield were studied, and the morphology, composition, and valence of the Sn deposits were examined. A maximum yield of over 90% in a 3 × 0.7 mm spot was achieved through the surface modification of Re filaments and optimisation of the electrodeposition parameters. As the Sn⁰ atomic state was predominant in the deposit, the average detection efficiency of the LRIMS device using the as-deposited Sn samples was approximately 3.63 × 10^-4, which was almost an order of magnitude higher than that of the sample dropped with graphene oxide solution (4.39 × 10^-5).