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 microg l(-1), and the relative standard deviation (n=10) was 2% for a concentration of 50 microg l(-1) and 7% for a concentration of 5 microg 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 HNO(3) and H(2)O(2). In general, there was no significant difference among data obtained from both methodologies, but pre-treatment with ozone is much faster.
Capelo
J L
JL
Departamento de Engenharia Química, Instituto Superior Técnico, Av. Rovisco Pais, Lisbon, Portugal. j_lcm2000@yahoo.es
Pedro
H A
HA
Mota
A M
AM