Fluoride estimations in water using ion selective electrode: Choice of appropriate TISAB

999-1002Choice of appropriate TISAB (total ionic strength adjusting buffer) plays a crucial role in fluoride (F¯) analysis in water samples by ion selective electrode. Despite this no guideline is, yet, available on the choice of appropri ate TISAB for F¯ analysis in samples, particularly in presence of other ionic and non-ionic species. In this study, the efficacy of ten different TISABs for fluoride estimati on in water samples in presence of F¯ binding cations, viz. A13+ and Fe3+ has been investigated. The study suggests that the TISA B, containing tris- hydroxymethyl aminomethane hydrochloride buffer is probably best suited for F¯ estimation in samples, especially, in presence of high concentrations (1-2 g dm-3) of Al3+