# Quick question about Pt



## Chameleon 12 (Nov 6, 2022)

I've read Hoke and several others as well here almost 24/7, and thank you guys and gals for the knowledge and care for safety.
My question is am I'm correct in my assumption that tests 2&3(clockwise) are indeed positive for Pt? I believe they are and I'm reading them correctly.
They came from IC four side flat packs, denoxed with sulfamic, dropped gold with smb, decided to less than simmer down to 2/3 original volume and test again with stannous.
Gold has been recovered, what's got me puzzled is no Pt/Pd was shown before gold was dropped.
Tested stannous against known gold test solution just to double check ( the positive for gold in the pic is not the test solution, it's another solution I'm working)


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## Lino1406 (Nov 7, 2022)

Very slight chance for Pd/Pt in this conditions, any reason to expect them?
1. The test is not strong enough
2. If there were Pt/Pd in low amounts they would join gold in SMB precipitation


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## Yggdrasil (Nov 7, 2022)

Chameleon 12 said:


> I've read Hoke and several others as well here almost 24/7, and thank you guys and gals for the knowledge and care for safety.
> My question is am I'm correct in my assumption that tests 2&3(clockwise) are indeed positive for Pt? I believe they are and I'm reading them correctly.
> They came from IC four side flat packs, denoxed with sulfamic, dropped gold with smb, decided to less than simmer down to 2/3 original volume and test again with stannous.
> Gold has been recovered, what's got me puzzled is no Pt/Pd was shown before gold was dropped.
> ...


Why double post like this?
It is against forum rules because it fills up the forum unnecessarily.
And yes it do resemble Pt, but it is easier to read on an cotton bud or paper strip.

Edit to add:
Even though it resembles Pt it may not be.
As Lino says are there a reason to expect it?
What kind of IC and how was it processed?


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## eaglekeeper (Nov 7, 2022)

I personally have never, at least to this point found Pt in standard IC chips. I'm not say there isn't any out there, but I've never seen it.

I find using a spot plate/spoons to test for PM's difficult to interpret sometimes, especially if there is a mix of PM's. I tear off a piece of filter paper and put a drop of the solution on it, then a drop of stannous. The initial color shift is important, but it's also important to let it set for a little while. If there is a mix of PM's you'll see a small amount of banding of other PM's...if present.

The first picture shows the initial color shift showing strong for Pt. Then 5 minutes later it shows strong for Pd, shown in picture 2. You can start to see a small amount of banding show up in the second picture. That is the same test strip, I just had to move it around to get the green to show on the picture... I need a better cell phone.

So I've learned to wait a little while before I immediately throw the test strip into my filter storage. Now I know where my Pd is at....it was there the whole time.

You notice I only use the spot plate to put things on now.


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## Chameleon 12 (Nov 7, 2022)

Lino1406 said:


> Very slight chance for Pd/Pt in this conditions, any reason to expect them?
> 1. The test is not strong enough
> 2. If there were Pt/Pd in low amounts they would join gold in SMB precipitation


Ic's came from decommissioned military and medical equipment circa 1988, I've read "some late 80's and early 90's chips used Pt/Pd alloys" I also remade stannous and tested again to the same result.
When left 48 hours after gold drop with SMB, one of the three solutions had grey/black precipitate layered with gold.


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## Lino1406 (Nov 7, 2022)

Advise, if amounts justify it, check precipitate by XRF qualitatively


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