Checking for precious metals with SnCl2

[Renaldas]

?I have several items sold me as "dental gold". I'm a dentist by myself, I know, there are huge variety of metals used for dental prosthesis. I prefer to check all these items without destroing them.
What do you think, will such a method work. I took ceramic plate, rub my item to it, heat the plate, put a drop of AR on this place, wait a little bit, immerse filtering paper piece into this drop and add a drop of SnCl2. If I see colors of gold/platinum/palladium, I'm satisfied.
I checked several items of my lot by this method, there were some of them showing no color change. Indeed, a saw that almost nothing happened with the traces of metal on my ceramic plate, the metal remained undissolved.
What do you think, can this method work if there are alloys with huge amounts of silver, nickel, chromium, cobalt, iron, copper and other metals, used in dentistry?

 

[Lino1406]

The sensitivity of Stannous chloride test goes
down to 4 ppm ! No color - no PM. Except Ni - gives
brown hue

 

[qst42know]

High silver alloys in AR may prevent any result. A nitric test first for silver may be prudent.

 

[Renaldas]

High silver alloys in AR may prevent any result. A nitric test first for silver may be prudent.

Dont you think the trace of metal on ceramic plate is thin enough, and AR could reach gold even if there is large amount of silver present?

 

[qst42know]

I have very little experience with dental alloys. None in refining them.

I have had some issues with silver chloride. Once coated with silver chloride items can be boiled in AR with no result.

From your experience in the dental industry how high of a silver content is found dental alloys?

 

[Renaldas]

I have very little experience with dental alloys. None in refining them.

I have had some issues with silver chloride. Once coated with silver chloride items can be boiled in AR with no result.

From your experience in the dental industry how high of a silver content is found dental alloys?

There are Ag-Pd alloys, where silver contents is about 75%. I think, these items could be boiled in nitric acid.

 

[qst42know]

I would expect anything with a 75% silver content to be completely immune to aqua regia.

I would not expect silver with a 25% palladium content to be resistant to nitric.

Inquarted palladium resistant to nitric acid :?: , That does not make sense to me, but it's not something I have dealt with.

Perhaps someone with experience with a similar silver palladium alloy will respond to this thread?

 

[Renaldas]

I would expect anything with a 75% silver content to be completely immune to aqua regia.

I would not expect silver with a 25% palladium content to be resistant to nitric.

Inquarted palladium resistant to nitric acid :?: , That does not make sense to me, but it's not something I have dealt with.

Perhaps someone with experience with a similar silver palladium alloy will respond to this thread?

I think traces on the plate acts in other way as huge solid piece of alloy, so, I propose, there is a possibility for AR to dissolve gold even if there are a lot of silver present.