title: Interference of thiosulfate during colorimetric analysis of hexavalent chromium using 1,5-diphenylcarbazide method.
abstract: Thiosulfate (S(2)O(3)(2-)) contained in the media for autotrophic Cr (VI) reduction was found to interfere with Cr (VI) measurement following the 1,5-diphenylcarbazide (DPC) method. The interference was confirmed at several abiotic and biotic conditions, and was influenced by S(2)O(3)(2-) concentration, pH, and the media components. At neutral to alkaline pH, 500 mg/L of S(2)O(3)(2-) did not cause interference, while 4 mg/L of S(2)O(3)(2-) resulted in the interference at pH 2.0. Atomic absorption spectrophotometry could be an alternative method when the interference by S(2)O(3)(2-) is expected.
authors.affiliation: Department of Environmental Engineering, Inha University, 253 Yonghyun-Dong, Nam-Gu, Inchon 402-751, South Korea.
authors.forename: Nirmala
authors.initials: N
authors.lastname: Bardiya
authors.forename: Yong-Woo
authors.initials: YW
authors.lastname: Hwang
authors.forename: Jae-Ho
authors.initials: JH
authors.lastname: Bae