Interference of Sodium Chloride in the Determination of Lithium by Atomic Spectrometry

摘要

Atomic spectrometry has been shown to be very attractive in the determination of lithium in biological samples because of its accuracy and convenience. However, chlorine and sodium have been reported to have interference in either flame or graphite furnace atomic spectrometry. We have investigated the interferences of sodium chloride in atomic spectrometric determination of lithium for biological samples, by nature, contain rather large amount of sodium chloride. The suppressive effect of chlorine has been found in all three kinds of detection modes (graphite furnace atomic absorption, flame atomic emission and flame atomic absorption). The possible mechanism was due to the formation of thermostable lithium chloride, which reduced the number of free lithium atoms in atomization stage. In flame atomic emission spectrometry, sodium caused a spectral interference and produced an emission signal at wavelength 670.8 nm.