How To Reduce Cu Interferences On Icp-Oes

[SteakSauce]

Hi everybody,

 

Im currently working on a copper collection technique for the precious metals.

Basically, PM is fused using fire assay procedure with copper collector, into a copper button, and typical dissolution is carried out using aqua-regia to make it into a solution (the procedure is very similar to that of NiS collector technique). The problem arises on the measurement step. I get very strong Copper interferences (typically overlapping signals) on my ICP-OES instrument. I even do very close matrix matching to reduce the matrix as much as possible, and still no luck. the Internal standard I use is with 100µg/ml Indium (10% by Volume of 1000µg/ml added to the flasks).

 

Could you please advise on what to do to reduce such interferences?