Determination of samarium by the use of 2-color 3-photon resonance ionization mass spectrometry

Abstract

Resonance ionization mass spectrometry (RIMS) been applied for the investigation of states of the samarium atom. The 1-color and 2-color RIMS have been used obtain optimal photoionization schemes and to determine the Sm content of standard solutions. For 1-color 3-photon ionization schemes maximum intensity of ion signal is observed at 577.86 nm. When 2-color 3-photon ionization is adopted for the ion detection, however, a level located at 17 831 cm^–1( ⁷F₃) from the ⁷F₂ state (812 cm^–1) is regarded as the most efficient first excited state for ionization. Among the 2-color schemes using a level 17 831 cm^–1 as the first excited state, a level located at 34 460.4 cm^–1 is regarded as the efficient excited state for the detection sensitivity. Based on this optimal scheme determination of Sm contents in concentrations of standard solutions is performed. The minimum amount of Sm which can be detected by 2-color photoionization scheme {4f⁶6s²⁷F₂ (812 cm^–1)→4f⁶6s6p⁷F₃° (17 831 cm^–1)→34 460.4 cm^–1 →continuum} is estimated as 200 fg.