title: 3-Ethyl-4-(p-chlorobenzylidenamino-4,5-dihydro-1H-1,2,4-triazol-5-one (EPHBAT) as precipitant for carrier element free coprecipitation and speciation of chromium(III) and chromium(VI).
abstract: A method for the separation and speciative determination of Cr(VI) and Cr(III) has been developed. The procedure is based on coprecipitation of Cr(III) on 3-ethyl-4-(p-chlorobenzylidenamino-4,5-dihydro-1H-1,2,4-triazol-5-one (EPHBAT) without carrier element. The Cr(III) can be selectively precipitated on EPHBAT in the pH range of 8.0-9.0, while Cr(VI) cannot be retained. Total chromium was determined after the reduction of Cr(VI) to Cr(III) with 0.5 mL of concentrated H2SO4 and 0.5 mL of ethanol. Cr(VI) concentrations were obtained as the respective differences between total chromium and Cr(III). Experiments were performed to optimize conditions, such as pH, amounts of EPHBAT, sample volume, etc. A preconcentration factor of 50-fold was achieved for Cr(III). The detection limit of the method for Cr(III) was 1.0 microg L(-1). To validate the developed method, the certified reference materials (NIST SRM 1573a and GBW 0703) were analyzed. The method was applied for the speciation of chromium in spiked natural water samples with satisfactory results.
authors: Gaziosmanpasa University, Faculty of Science and Arts, Chemistry Department, 60250 Tokat, Turkey.
authors: Ozgur Dogan
authors: OD
authors: Uluozlu
authors: Mustafa
authors: M
authors: Tuzen
authors: Durali
authors: D
authors: Mendil
authors: Bahattin
authors: B
authors: Kahveci
authors: Mustafa
authors: M
authors: Soylak
mesh_terms: D002857:Chromium / Q000737:chemistry / Q000302:isolation & purification*; D004305:Dose-Response Relationship, Drug; D006863:Hydrogen-Ion Concentration; D007477:Ions; D018515:Plant Leaves / Q000378:metabolism; D013054:Spectrophotometry, Atomic / Q000379:methods; D013997:Time Factors; D014131:Trace Elements / Q000302:isolation & purification; D014230:Triazoles / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*
chemical_list: C546209:3-ethyl-4-(p-chlorobenzylidenamino)-4,5-dihydro-1H-1,2,4-triazol-5-one; C112392:4,5-dihydro-1H-1,2,4-triazol-5-one; D007477:Ions; D014131:Trace Elements; D014230:Triazoles; D014874:Water Pollutants, Chemical; D002857:Chromium