# Determining Palladium Solution Concentration



## kadriver (Aug 11, 2012)

I wanted to know how much dissolved palladium solution I had as measure in grams per liter.

I had a solution of palladium that I dissolved out of some mixed (Pt, Rh, Pd) black powder recovered from catalytic converters.

The process I used to get this palladium solution can be viewed here:

http://goldrefiningforum.com/phpBB3/viewtopic.php?f=51&t=14881

Fisrt, I had a known concentration of Pd solution that I made by dissolving .1 grams of palladium in 100ml of liquid - Standard Palladium Test Solution.

You can make your own Standard Test Solutions of gold, platinum, and palladium - see Hoke's book, "Refining Precious Metal Wastes" on page 93.

Hoke's book is available as a free download on this forum.

To begin, I added 9 drops of distilled water to the 4 top wells of a spot plate.

I then added 1 drop of the unknown palladium solution to the 9 drops of distilled water in the first well of the spot plate.

To mix this first well properly, I drew the mixture of 1 drop of unknown palladium solution and 9 drops of distilled water from the first well into the empty pipette and expelled it back into the first well.

I then drew 1 drop from this same well (number 1) and added it to the 9 drops of water in the second well, thus reducing the concentration by a factor of 10.

Again, I drew the contents of the second well (after adding 1 drop from the first well) into my empty pipette and expelled it back into the second well.

I repeated this process with the remaining two wells so that I had a reduction in concentration across the top row of wells from left to right.

 Edit one time to correct error in photo wording


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## kadriver (Aug 11, 2012)

I placed 1 drop of stannous chloride test solution in each of the 4 wells across the top of the spot plate.

The center row is a few drops from my Standard Palladium Test Solution.


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## kadriver (Aug 11, 2012)

Row A of the photo below contains the unknown sample being tested.

Row B is the sample of known test solution (known solution = 1 gram per liter).

To give a good comparison, I placed 10 drops of my known Standard Palladium Test Solution in the first well of the bottom row on the spot plate - B1.

Then I placed 9 drops of distilled water in the remaining 3 wells - B2, B3, and B4.

I took 1 drop from B1 (known test solution of 1g/Liter) and added it to the 9 drops of distilled water in B2.

After mixing B2, I took 1 drop from B2 and added it to the 9 drops of distilled water in B3 and so on.

I then added 1 drop of stannous chloride to each of the wells on the bottom row.

I looks like my unknown solution is about twice as strong as the known test soluiton.

I would conclude that the concentration of the unknown sample to be about 2 grams per liter.

As always - comments and critique is welcomed.

kadriver


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