yellow platinum salt precipitate

[arthur kierski]

what is happening when the yellow salt precipitated from a chloride solution with nh4cl is not yellow?it is brownish(light),orange red,and strong deep yellow------
what should i do?
please help---it seems that i am extracting all the pgms from cats (of course not all the rh) ---since i do twice the same extraction and in the second time the stanous test does not show any pgms----
my problem know seems to separate well the pgms from each other
thanks
Arthur

 

[Lou]

If it's brownish that can mean low levels of iridium, or higher amounts of rhodium.

If it's orange red, that means you've got too much chlorine in solution and Pd is co-precipitating.

If it's a strong deep yellow, then that's a good sign.

If there's a light, apple green color, then it's slight rhodium contamination.

 

[arthur kierski]

thanks Lou---once again you cleared my mind