In order to determine the mercury content present as a contaminant in samples of bleach used in water and food disinfection, a method for sample treatment using chloridric acid to eliminate the chlorine was proposed. The technique of cold vapour atomic absorption spectrophotometry, used to quantify the mercury, showed a recovery of 103%. Sixty nine samples of bleach were analysed and the values found for the median and 90th percentil were respectively, 15 and 67 mg/L. According to the values of residual mercury found and using the quantities of bleach recommended by the Brazilian Sanitary Authorities, the use of these disinfectants offers no risk to human health.
Mercury; Spectrophotometry, atomic absorption; Disinfectants
