Nioximates

This reagent, to which the name nioxime has been given, ia employed for the determination of palladium and may also be used for nickel it is soluble in water, and possesses advantages over dimethylglyoxime. The latter is used as a solution in alcohol and may therefore contaminate the palladium or nickel precipitate when added to an aqueous solution. 

Cyclohexane-l,2-dione dioxime (Nioxime) [492-99-9] M pK 11.92. Crystd from alcohol/water and dried in a vacuum at 40°. 

Cyclohexane-1,2-dione dioxime (nioxime) (IV) is more soluble in water (8.2 g L 1 at 21 °C) than is dimethylglyoxime it is an excellent reagent for the gravimetric determination of palladium. 

Current-voltage curve 594 Cyanide, D. of as silver cyanide, (g) 48l with silver nitrate, (ti) 358 titration with silver nitrate, 309, 358 Cyclohexane, D. of (ir) 756 Cyclohexane-1,2-dione dioxime see Nioxime... 

Nickel, sepn. of plus cobalt, (cm) 583 Nickel ware 96 Nioxime 439, 474 NITA (nitriloacetic acid) 57 Nitrates, D. of as nitron nitrate, (g) 484 by ammonium iron(II) sulphate, (am)... 

Palladium, D. of as dimethylglyoximate. (g) 463 as nioximate, (g) 474 by EDTA, (ti) 329 Paper chromatography 229 see Thin layer chromatography Parallax errors due to, 85 Parallel determinations 132 Partial ionic equations 850, (T) 851 Partition chromatography 13. 217 Partition coefficient 162 Patton and Reeder s indicator 317, 328 Peptisation 419. 421... 

Donat and Bruland [217] determined low levels of nickel and cobalt in seawater by a voltammetric technique, and the nioxime complexes of the two elements were concentrated on a hanging mercury drop electrode. The current resulting from the reduction of Co (II) and Ni (II) was measured by differential pulse cathodic stripping voltammetry. Detection limits are 6 pM (cobalt) and 0.45 nM (nickel). 

Cyclohexane-1,2-dione dioxime (nioxime) complexes of cobalt (II) and nickel (II) were concentrated from 10 ml seawater samples onto a hanging mercury drop electrode by controlled adsorption. Cobalt (II) and nickel (II) reduction currents were measured by differential pulse cathodic stripping voltammetry. Detection limits for cobalt and nickel were 6 pM and 0.45 mM, respectively. The results of detailed studies for optimising the analytical parameters, namely nioxime and buffer concentrations, pH, and adsorption potential are discussed. 

Nicotinic acid, p266 Nicotinonitrile, c329 Ninhydrin, il3 Nioxime, c361 2,2, 2"-Nitrilotriethanol, t266 1,1, l"-Nitrilotris(2-propanol), t325 2-Nitro-/ -anisidine, m89 5-Nitro-o-anisidine, m90 Nitroanisoles, m81, m92... 

C6H10N2O2 Nioxime (1,2-Cyclohexanedione dioxime) Extraction-photometric Fe, Ni 3... 

Neutralisation equivalent, determination of, 360, 1071 Nicol prism, 503 Nicotinamide, 850 Nicotinic acid, 848 isoNicotinic acid, 848 Ninhydrin, 436, 993, 994,995 Nioxime, 974, 975... 

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