Stannous chloride.

[CosmoIridium]

Can anyone comment on the detection limits of stannous chloride for Au in a mixed metal solution?
I did a search and there are some information, but none defined the detection limits.

 

[4metals]

It is difficult to pin down a specific answer because the strength of the acid affects the color in low concentrations. However I have seen it reproducibly indicate gold chloride down to 5 PPM.