title: Extractive spectrophotometric determination of micro and sub-micro amounts of fluoride.
abstract: A simple and sensitive extractive spectrophotometric determination of fluoride with the cerium(III)-alizarin complexan chelate has been investigated. The fluoro chelate formed is extracted into n-pentanol containing triethylamine. It is possible to achieve under selected conditions a selective extraction of the cerium(III)alizarin complexan-fluoride chelate. The stability of the chelate, the effect of temperature and the low absorbance of the blank are discussed. It is found that it is necessary to add a pH 9 buffer before the extraction. Procedures are given for the determination of 0.1-1 mug of fluoride in a 4-ml sample and 5-25 mug of fluoride in a 90-ml sample.
authors.affiliation: Analytisch Chemisch Laboratorium of the State University Croesestraat 77A, Utrecht, The Netherlands.
authors.forename: J P
authors.initials: JP
authors.lastname: Haarsma
authors.forename: J
authors.initials: J
authors.lastname: Agterdenbos