Interference of thiosulfate during colorimetric analysis of hexavalent chromium using 1,5-diphenylcarbazide method.
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.
Bardiya
Nirmala
N
Department of Environmental Engineering, Inha University, 253 Yonghyun-Dong, Nam-Gu, Inchon 402-751, South Korea.
Hwang
Yong-Woo
YW
Bae
Jae-Ho
JH