  We perform an analytic calculation of thermoelectric transport coefficients
for massless Dirac electrons using the approach based on the Kubo--St\v{r}eda
formula and generalized Mott's relation. The main focus of the letter is made
on the properties of the Nernst coefficient in the vicinity of the Dirac point
in quantum limit. We calculate magnetic field and temperature dependencies of
the Nernst coefficient and compare our results with recent experiments in
$\alpha$-(BEDT-TTF)$_{2}$I$_{3}$ organic conductor. We argue that the Zeeman
splitting is important to understand the experimental data at high magnetic
fields.
