  Asteroseismic modelling of the internal structure of main-sequence stars born
with a convective core has so far been based on homogeneous analyses of space
photometric Kepler light curves of 4 years duration, to which most often
incomplete inhomogeneously deduced spectroscopic information was added to break
degeneracies. We composed a sample of 111 dwarf gravity-mode pulsators observed
by the Kepler space telescope whose light curves allowed for determination of
their near-core rotation rates. For this sample we assembled HERMES
high-resolution optical spectroscopy at the 1.2-m Mercator telescope. Our
spectroscopic information offers additional observational input to also model
the envelope layers of these non-radially pulsating dwarfs. We determined
stellar parameters and surface abundances in a homogeneous way from atmospheric
analysis with spectrum normalisation based on a new machine learning tool. Our
results suggest a systematic overestimation of [M/H] in the literature for the
studied F-type dwarfs, presumably due to normalisation limitations caused by
the dense line spectrum of these rotating stars. CNO-surface abundances were
found to be uncorrelated with the rotation properties of the F-type stars. For
the B-type stars, we find a hint of deep mixing from C and O abundance ratios;
N abundances have too large uncertainties to reveal a correlation with the
rotation of the stars. Our spectroscopic stellar parameters and abundance
determinations allow for future joint spectroscopic, astrometric (Gaia), and
asteroseismic modelling of this legacy sample of gravity-mode pulsators, with
the aim to improve our understanding of transport processes in the
core-hydrogen burning phase of stellar evolution.
