and where it provides most of our knowledge of the chemical evolution of the Universe at high redshift, through abundances in DLAs (Pettini et al. 1999; Prochaska & Wolfe 2002).

Zinc abundance derivation is important given its production in different nucleosynthesis processes and environments: weak s-process in hydrostatic phases of He and C burning in massive stars, complete and incomplete Si-burning, explosive burning in core-collapse SNe, and the main s-process in low and intermediate mass stars (e.g. Umeda & Nomoto 2002; Bisterzo et al. 2004). Zinc is in the so-called upper iron group with atomic masses in the range 57$\leq$A$\leq$ 66, which includes species up to $^{66}$Zn (Woosley & Weaver 1995). Umeda & Nomoto (2002) show that in massive stars, the iron-peak elements Cr, Mn, Co, and Zn are produced in complete Si-burning with a peak temperature T$_{\rm peak}$ $>$ 5$\times$10$^{9}$ K and in incomplete Si-burning at temperatures in the range 4$\times$10$^{9}$ $<$ T$_{\rm peak}$ $<$ 5$\times$10$^{9}$ K. They also found that \[Zn/Fe\] is greater for deeper mass cuts in the explosion process, smaller neutron excess, and higher explosion energies and that a higher Zn abundance results from deep mixing of complete Si-burning products and a fallback. At lower metallicities, 