DETERMINATION OF SAMARIUM BY THE USE OF 2-COLOR 3-PHOTON RESONANCE IONIZATION MASS-SPECTROMETRY

Resonance ionization mass spectrometry (RIMS) been applied for the inv estigation of states of the samarium atom. The 1-color and 2-color RIM S have been used obtain optimal photoionization schemes and to determi ne the Sm content of standard solutions. For 1-color 3-photon ionizati on schemes maximum intensity of ion signal is observed at 577.86 nm. W hen 2-color 3-photon ionization is adopted for the ion detection, howe ver, a level located at 17831 cm(-1)(F-7(3)) from the F-7(2) State (81 2 cm(-1)) is regarded as the most efficient first excited state for io nization. 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 a s 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 {4f(6)6s(2) F-7(2) (812 cm (-1)) --> 4f(6)6s6p(7)F(3)degrees (17 831 cm(-1)) --> 34 460.4 cm(-1) --> continuum} is estimated as 200 fg.