title: Thulium hydroxide: a new coprecipitant for speciation of chromium in natural water samples.
abstract: A coprecipitation procedure has been established for chromium speciation in natural water samples. The procedure is based on the coprecipitation of Cr(III) on thulium hydroxide precipitate. After reduction of Cr(VI) to Cr(III) by using potassium iodide, the presented method was applied to the determination of the total chromium. The level of Cr(VI) is calculated by difference of total chromium and Cr(III) levels. The procedure was optimized for some analytical parameters including pH, sample volume, matrix effects, etc. The detection limits based on 3sigma criterion were 0.87 microg L(-1) for Cr(III) and 1.18 microg L(-1) for Cr(VI). The procedure presented was validated by the analysis of BCR-144R Sewage Sludge (domestic origin). The presented method was applied for the speciation of chromium in environmental sample with satisfactory results (recoveries>95%, R.S.D.s<10%).
authors.affiliation: Erciyes University, Faculty of Art and Science, Department of Chemistry, 38039 Kayseri, Turkey.
authors.forename: Funda Armagan
authors.initials: FA
authors.lastname: Aydin
authors.forename: Mustafa
authors.initials: M
authors.lastname: Soylak
mesh_terms: D011232:Chemical Precipitation; D002857:Chromium / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D012680:Sensitivity and Specificity; D013932:Thulium / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D014874:Water Pollutants, Chemical; D002857:Chromium; D013932:Thulium