  The absolute mass value of $^{168}$Yb has been directly determined with the
JYFLTRAP Penning trap mass spectrometer at the Ion Guide Isotope Separator
On-Line (IGISOL) facility. A more precise value of the mass of $^{168}$Yb is
needed to extract possible signatures of beyond standard model physics from
high-precision isotope shift measurements of Yb atomic transition frequencies.
The measured mass-excess value, ME($^{168}$Yb) = $-$61579.846(94) keV, is 12
times more precise and deviates from the Atomic Mass Evaluation 2016 value by
1.7$\sigma$. The impact on precision isotope shift studies of the stable Yb
isotopes is discussed.
