Resumo

GUEVARA RUIZ, Paulina  e  ORTIZ PEREZ, María Deogracias. Micorescale adaptation of the potentiometric method with ion selective electrode for quantification of fluoride. Rev. Int. Contam. Ambient [online]. 2009, vol.25, n.2, pp.87-94. ISSN 0188-4999.

Similarly to other countries, ground water from México is naturally polluted by fluoride. The main effects of fluoride at typical ground water concentrations are dental fluorosis, neurological deficits and reproductive disorders. In order to verify that the fluoride concentration is within the allowed guideline in México (NOM 127 and 201), it is important to monitor fluoride levels in water and commercial beverages. The aim of this work is to develop a modification of the standard potentiometric method for fluoride determination in water, in order to reduce costs and amount of potentially toxic waste substances. Both methods were validated, the standard potentiometric method with the ion selective electrode and the microscale modification proposed in this paper. The methods were compared using statistic tests and graphics, followed by the comparison of 125 samples of commercial bottled water sold in the city of San Luis Potosí. Optimal results were obtained for the validation of both methods, and the microscale modification showed statistically identical results to those obtained with the standard method in all samples of bottled water. The microscale modification is a good alternative for fluoride assessment in water and beverages, and it represents a 95 % reduction of costs and chemical waste.

Palavras-chave : fluoride; water pollution; bottled water; ion selective electrode.