Re: Which Cation can be tested for using Dimethylglyoxine?

Dear Talha Ali

In adition to Ni, this reagant is most commonly used for the quantitative 
analysis for Palladium. It has also been used [but not very often] for Fe, 
Cu, Co, and Bi.

For Ni, the solution must be only very faintly acidic [pH > 5] neutral, or 
slightly ammoniacal. The water-insoluble precipitate is intense red in 
color. Add a little ammoniun citrate or tartrate to prevent 
interference by hydrolysis and precipitation of Fe,Al, etc. if present

Ferrous iron [FeII] forms a pink, SOLUBLE compound under these above 
conditions, which can be confused with the INSOLUBLE  Ni compound. To avoid 
this interference, oxidize the Iron to FerrIC before adding the reagent

For Pd, the solution must be cool, and acidic,  0.2 - 1.5 N HCl  [2 - 5 % 
V/V in HCl]. A bright yellow precipitate is formed.  This is nearly a 
specific reagent for Pd under these conditions.

Bismuth with this reagent in hot strongly ammoniacal solution forms an 
intense bright yellow precipitate - a very sensitive test for Bi.

 Let me know if you need more information on this.

                     Regards
                     Charlie A. Crutchfield