  We present results from dual-abundance photoionization modelling of the
planetary nebula SMC N87 (SMC-SMP 27). The models succesfully resolve the
observed discrepancy between the heavy-element abundances derived
semiempirically from the optical recombination lines and the collisionally
excited lines, incorporating a H-poor gaseous component in the main body of the
PN. The mass of the H-poor plasma is only about 1 per cent of the total PN
ionized mass and its electron temperature is 6300 K. The average heavy element
abundances in the PN approximate those returned by the ICF method using the
collisionally excited lines (for t^2 = 0), while the He abundance is less than
the one found empirically. The C/O ratio in the H-depleted component is smaller
than in the normal metallicity gas, in contrast to stellar nucleosynthetic
models which predict the opposite for processed material ejected from an
evolved PN nucleus.
