  Spectroscopic observations of 48 emission-line objects of M33 have been
obtained with the multi-object, wide field, fibre spectrograph AF2/WYFFOS at
the 4.2m WHT telescope (La Palma, Spain). Line intensities and logarithmic
extinction, cbeta, are presented for 42 objects. Their location in the Sabbadin
& D'Odorico diagnostic diagram (Halpha/[SII] vs Hlapha/[NII]) suggests that
>70% of the candidates are Planetary Nebulae (PNe). Chemical abundances and
nebular physical parameters have been derived for the three of the six PNe
where the 4363A [OIII] emission line was measurable. These are disc PNe,
located within a galactocentric distance of 4.1 kpc, and, to date, they are the
farthest PNe with a direct chemical abundance determination. No discrepancy in
the Helium, Oxygen and Argon abundances has been found in comparison with
corresponding abundances of PNe in our Galaxy. Only a lower limit to the
sulphur abundance has been obtained since we could not detect any [SIII] line.
N/H appears to be lower than the Galactic value; some possible explanations for
this under-abundance are discussed.
