Ozone treatment for mercury determination in white wines

A method was developed for the generation of mercury vapour by means of cold-vapour flow-injection atomic absorption spectrometry (FI-CV-AAS) from white wine samples after ozonation as sample pre-treatment. Two different reactors designs for sample ozonation were developed and investigated. The limit of detection and the limit of quantification were, respectively, 0.5 and 1.7 mug l(-1), and the relative standard deviation (n = 10) was 2% for a concentration of 50 mug l(-1) and 7% for a concentration of 5 mug l(-1). The pre-treatment with ozone has allowed to reduce drastically the amount of chemical reagents (e.g. carrier agent and reducing agent) used in the FI-CV-AAS system. The mercury content of wine samples was also determined by FI-CV-AAS after pre-concentration in the presence of HNO3 and H2O2. In general, there was no significant difference among data obtained from both methodologies, but pretreatment with ozone is much faster. (C) 2003 Elsevier B.V. All rights reserved.