DETERMINATION OF RUBIDIUM ISOTOPES BY USING SATURATED ABSORPTION-SPECTROSCOPY AND A SEE-THROUGH HOLLOW-CATHODE GLOW-DISCHARGE CELL

Saturated absorption spectroscopy using a narrow band diode laser was applied to the determination of Rb in a laboratory-built see-through h ollow cathode glow discharge cell, The D-1 (794.7 nm) and D-2 (780.1 n m) transition lines were investigated and the hyperfine structures of Rb-85 and Rb-87 were clearly resolved, The abundance ratio of the two isotopes was calculated by integrating the signals of the correspondin g isotopes, the ratios being accurate to within 6% compared with the n atural abundance, Aqueous standard solutions of Rb were used to determ ine the sensitivity of the system, The minimum detectable amount of Rb was 20 pg or less; The technique is comparable to high resolution mas s spectrometry.