Preliminary data on the fractionation of ytterbium isotopes in a Yb(III)-acetate/Yb-amalgam exchange system were obtained. The light isotope was preferentially fractionated to the amalgam phase. The values of the unit separation gain per mass difference, epsilon, were found to be - 0.00054 for Yb-176/171 and -0.00069 for Yb-176/174. The difference, which amounted to 0.00015, may be taken as evidence for the occurrence of the so-called "even-odd" effect. It was also found that the chemical isotope shift of ytterbium was mirrored by the optical isotope shift in its atomic spectra.