T. Yotsuyanagi, Y. Takeda, Ryuji Yamashita
Dec 1, 1973
Citations
0
Influential Citations
33
Citations
Journal
Analytica Chimica Acta
Abstract
Abstract The extraction-spectrophotometric determination of chromium(III) with 4-(2-pyridylazo)-resorcinol (PAR) is described. PAR(H 2 R) forms a 1:3 complex with chromium(III) in a boiling acetate buffer solution at pH 5. The complex forms an ion-association compound with tetradecyldimethylbenzylammonium ion (TDBA + ):Cr(R)(HR) 2 - -TDBA + which can be extracted into chloroform, the molar absorptivity being 4.7 ·10 4 at 540 nm. If EDTA is added as a masking agent after the Cr(HR) 3 has been formed, only iron, cobalt and nickel interfere seriously, and the method can be made specific for chromium by a preliminary extraction of these metals with cupferron. The sensitivity of the method is seven times higher than that of the diphenylcarbazide method.