title: Speciation of chromium in Australian fly ash.
abstract: The concentrations of chromium (III) and (VI) in fly ash from nine Australian coal fired power stations were determined. Cr(VI) was completely leached by extraction with 0.01 M NaOH solution and the concentration was determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). This was confirmed by determining Cr(III) and Cr(VI) in the extracts of fly ash that had been spiked with chromium salts. These analytical measurements were done using a combination of ion-exchange chromatography and ICP-AES. The elutant was 0.05 M HNO(3) containing 0.5%-CH(3)OH. When the column was operated at a flow rate of 1.2 ml min(-1) and samples were injected by use of a sample loop with a volume of 100 microl, Cr(III) and Cr(VI) in sample solution was exclusively separated within approximately 10 min. The detection limits (3sigma) were 5 ng for Cr(III) (0.050 mg l(-1)) and 9 ng for Cr(VI) (0.090 mg l(-1)), respectively. A relative standard deviation of 1.9% (n=6) was obtained for the determination by IC-ICP-AES of 0.25 mg l(-1) Cr(III) and Cr(VI).
authors.affiliation: Inorganic Analytical Chemistry Division, National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology, Tsukuba Central 3, 1-1-1 Umezono, Tsukuba, Ibaraki, Japan. tomohiro-narukawa@aist.go.jp
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Narukawa
authors.forename: Kenneth W
authors.initials: KW
authors.lastname: Riley
authors.forename: David H
authors.initials: DH
authors.lastname: French
authors.forename: Koichi
authors.initials: K
authors.lastname: Chiba