1 Introduction

The determination of detailed abundances requires a high resolving power (>$30\,000$) and a wide spectral range. In order to satisfy both requirements simultaneously, echelle spectrographs must be used. ELODIE (Baranne et al. 1996, hereafter BQ96) is a fiber-fed echelle spectrograph with a resolution of $R=42\,000$ attached to the 1.93m telescope of the Observatoire de Haute-Provence (OHP), France. This spectrograph and its reduction software were optimized to measure accurate radial velocities.

In this paper we first show what precautions have to be taken to use ELODIE for other spectroscopic analyses, in our case detailed abundance determinations. To achieve our goal we had to make another reduction, starting from the raw image and taking special care in the removal of scattered light. Another important point in the reduction is to paste together the different orders of the spectrum and normalize them. Secondly, we present a method to estimate abundances with synthetic spectra adjustments. This method is an improvement of that of Hill & Landstreet (1993, HL93 hereafter). It is automated as much as possible and is able to analyse stars with various rotational velocities (up to 150  ${\rm km~s^{-1}}$), for which the equivalent width method is not applicable. Finally, to assess the validity of this method, we compare the abundances derived for Vega ($\alpha$ Lyr = HR 7001 = HD 172167) and the Sun with those in the literature. These two reference stars are used to check the code's validity for stars having effective temperatures between those of the Sun and of Vega.

Analysis tools with related goals but different approaches have been developed by Valenti & Piskunov (1996), Cowley (1996) and Takeda (1995a). Takeda's method has been used by Varenne & Monier (1999) to derive abundances of A and F-type stars in the Hyades open cluster.