2,2 -dipyridyl-2-pyridylhydrazone

Kouimtzis et al. [232] described a spectrophotometric method for down to xg/l cobalt in seawater, in which the cobalt is extracted with 2,2/-dipyridyl-2-pyridylhydrazone (DPPH) [233,235-238], the cobalt complexisback-extracted into 20% perchloric acid, and this solution is evaluated spectrophotometrically at 500 nm. This avoids many of the sources of error that occur in earlier procedures. 

Recently, the complexation of cobalt with 2,2 -dipyridyl-2-pyridylhydrazon at pH 5-8 and its extraction from sea water and brines into iso-amyl alcohol has been recommended. The cobalt complex can be back-extracted into dilute perchloric acid 76). 

Many hydrazone derivatives have been proposed as spectrophotometric reagents for Co, namely 2,2 -dipyridyl-2-pyridylhydrazone (e = 4.2-10 ), 2-furaldehyde-2-pyridylhydrazone [79], benzil-2-pyridylketone-2-pyridylhydrazone [80], and 2,2 -dipyridyl-2-benzothiazolyl-hydrazone [81]. Co was determined in the presence of Hg [82], and in the presence of Ni [83] by the derivative spectrophotometry using benzil-2-pyridylketo-2-quinolylhydrazone. 

Themelis D. G., Tzanavaras P. D., Kika F. S. and Sofoniou M. C. (2001) Flow-injection manifold for the simultaneous spectrophotometric determination of Fe(II) and Fe(III) using 2,2 -dipyridyl-2-pyridylhydrazone and a single-line double injection approach. Fresenius Journal of Analytical Chemistry, 371,364-368. 

Zn(ll) Serum, human hair, and Pharmaceutical formulation Complex formation with 2,2 -dipyridyl-2-pyridylhydrazone in strong alkaline medium (selective demasking of the KCN complex with formaldehyde)... 

Captopril Pharmaceutical formulation Inhibition of the complex Co(ll)-2,2 -dipyridyl-2-pyridylhydrazone... 

Themelis, D. G., R D. Tzanavaras, and F. S. Kika. 2001. On-line dilution flow injection manifold for the selective spectrophotometric determination of ascorbic acid based on the Fe(II)-2,2 -dipyridyl-2-pyridylhydrazone complex formation. Talanta 55 127-134. 

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