Differential chemical abundances derived here for the hot post-AGB star LS IV-12 111 (IRAS 19590-1249) compared with the previous results of McCausland et al. (1992) and Ryans et al. (2003). The black line shows the solar abundance reference of Asplund et al. (2006). The error bars in our study and in Ryans et al. (2003) represent standard deviations whilst it indicates the uncertainty in the abundance determination of McCausland et al. (1992).