Measurement of the rubidium content in a standard reference sample applying isotope dilution in diode laser graphite furnace atomic absorption spectrometry
Hd. Wizemann, Measurement of the rubidium content in a standard reference sample applying isotope dilution in diode laser graphite furnace atomic absorption spectrometry, J ANAL ATOM, 15(10), 2000, pp. 1401-1403
The reliability of the isotope dilution technique applied to diode laser gr
aphite furnace atomic absorption spectrometry was tested by the determinati
on of the Rb content in a NIST (National Institute of Standards and Technol
ogy) reference water (SRM 1640). For the measurements, the NIST water was s
piked with different amounts of Rb-87. The signals of both naturally occurr
ing Rb isotopes, Rb-85 and Rb-87, were measured simultaneously by the use o
f two diode lasers. A total Rb content of 1.97 +/- 0.03 ng ml(-1) was found
which compares very well with the reference value of 2.00 +/- 0.02 ng ml(-
1).