Spectrophotometric determination with diacetyl dioxime dimethylglyoxime

1 Spectrophotometric determination with diacetyl dioxime (dimethylglyoxime) 

In the presence of a strong oxidizing agent such as bromine or ammonium peroxodisulphate, nickel (II) ions form a wine-red to brown-coloured 

The nickel-diacetyl complex can be measured photometrically in the aqueous solution directly (modification A) or following extraction with chloroform and re-extraction (modification B). 

The method in the form of modification A is suitable for ground water and surface water, and for waste waters after appropriate pretreatment. Without dilution or concentration 0.02 - 5 mg/1 of nickel (II) can be determined. 

In the presence of cyanides the samples should be mineralized due to the complex bonding of Ni(CN)z i2-. In this process interfering organic impurities are simultaneously eliminated. Evaporate the samples (30 - 1000 ml) under a fume hood with 2 ml of concentrated sulphuric acid and 2 - 3 ml of concentrated nitric acid until SO3 vapour appears. If the solution is still 

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