title: Sensitive reversed-phase liquid chromatographic determination of fluoride based on its ternary systems with zirconium(IV) or hafnium(IV) and 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol.
abstract: Optimum conditions for the direct reversed-phase LC determination of fluoride based on the ternary M-(F-)-(5-Br-PADAP) complexes [M = ZrIV or HfIV and 5-Br-PADAP = 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol] were evaluated. Chromatographic separation was performed with C18 end-capped column with an eluent consisting of acetonitrile-water (85 + 15 v/v) mixture of pH 4.0 +/- 0.3 (flow rate 1 ml min-1), and the eluate was monitored spectrophotometrically at lambda max = 585 nm. The calibration curves were linear over a wide range of fluoride concentrations: from 1 to 110 and 150 ng ml-1 for the ZrIV-(F-)-(5-Br-PADAP) and HfIV-(F-)-(5-Br-PADAP) systems, respectively (using a 20 microliters loop). Under such conditions the detection limits were 0.8 and 0.7 ng ml-1, respectively, and the quantification limit is 1.0 ng ml-1 for both methods. When a 100 microliters loop was used, the limits of both detection and quantification in the method based on the zirconium system were 0.2 ng ml-1. Using the proposed method, fluoride was determined directly in tap water, saliva and an anti-cancer agent for prostatic cancer (Leuprolid).
authors.affiliation: Warsaw University of Technology, Faculty of Chemistry, Department of Analytical Chemistry, Poland.
authors.forename: S
authors.initials: S
authors.lastname: Oszwałdowski
authors.forename: R
authors.initials: R
authors.lastname: Lipka
authors.forename: T
authors.initials: T
authors.lastname: Majewski
authors.forename: M
authors.initials: M
authors.lastname: Jarosz
mesh_terms: D018931:Antineoplastic Agents, Hormonal / Q000737:chemistry; D002853:Chromatography, Liquid; D005459:Fluorides / Q000032:analysis*; D006801:Humans; D016729:Leuprolide / Q000737:chemistry; D012463:Saliva / Q000737:chemistry*; D012680:Sensitivity and Specificity; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D018931:Antineoplastic Agents, Hormonal; D014874:Water Pollutants, Chemical; D016729:Leuprolide; D005459:Fluorides