View Full Version : Aqua Regia - ether extraction of DSS

07-14-2009, 07:02 AM
I took 50 grams of Dead Sea salt and added aqua regia made with 3 parts HCl and 1 part HNO3, about 100 ml.
I let this sit two days.
I then decanted the aqua regia into another beaker and dilluted it with distilled water.

Then I added 30 ml diethyl ether, three times, mixing well by stirring and pipetting the ether layer off each time.
I let the ether evaporate in a sandbath at about 50C and at room temperature near the end.

I was left with a few ml of a clear liquid with a faint yellow translucent tint.

I added KOH and noticed a very small amount of white clouds-strings appearing indicating a precipitate forming
The liquid was still yellowish clear.
I added some H2O2. Nothing else preciptiated.
I added distilled white vinegar to neutralize the alkalinity somehow, and noticed the color disappeared and there appeared a milky white color.
The pH tested as about neutral (6-7).

There is a very small amount of very fine white precipitate that appeared and is settling now.

If there is m-gold in DSS there is probably very little or the extraction didn't work well.

07-15-2009, 10:40 AM
I had some of the clear-faint-light-yellow extract after the ether was evaporated off left to which I had not added KOH.

I added NH4NO3 to it. About half the total amount of the oily liquid left. It dissolved.

Then I added dropwise NH4OH. I measured the pH after each drop by dipping a glass rod into it then onto paper, and it was measuring red-acid each time. I added three times one drop, still acid. So I added two drops at a time totalling 5, and noticed blue indicating alkalinity. I should have added 4 apparently so I took very dillute HCl and added drop by drop again until I had neutral.

I noticed after adding 3 drops NH4OH, that the clear oily liquid turned a golden yellow. Really darkened in color. And after the addition of the first two drops I smelled and noticed ammonia fumes (visible ones) coming off.

The intent was to get a neutral solution, neutralizing any Cl bound to the gold into NH4Cl.

Now I wonder how come the color darkened. Metallic?

I now should have NH4Cl and NH4NO3 in the mix with probably gold.

My guess for why there were ammonia fumes coming off is that the NH4OH reacted with the gold as chloride forming HCl , NH3 that gassed off, and gold uh as something I guess diatomic metallic but it wasn't red?

07-19-2009, 08:35 AM
I did a larger batch extraction in a slightly different way.
I took 200-250 grams of Dead Sea salt and added demineralized water to dissolve it up to 800 ml, then added 100 ml aqua regia.

I let this react a day, then ether extracted three times with 100 ml ether each time.

Every time the ether got colored deep yellow, like goldchloride!

I let this evaporate over the course of two days, and now am left with almost nothing, like a few ml of clear liquid with a few yellow oily spots in it.

The goldchloride color in the ether was likely from bromine.

07-19-2009, 05:46 PM
I did however add ammonia to the clear to faint yellow liquid left. There was like 10 ml left, so I added 10 drops, then 5, then drop by drop testing the pH after each drop with the intent to neutralize it.
Every time I added a drop, especially in the beginning, a LOT of ammonia fumes were visibly coming off. I smelled them too.

When I got near neutral, the color darkened to a golden yellow, similar to the color of the ether after extraction.

Did bromine get liberated from a salt and end up as traces in the liquid giving rise to the color?

07-22-2009, 04:07 PM
I got another interesting result.

Last week I took a clear to yellow extract from DSS, and carefully neutralized to pH neutral drop by drop with NH4OH. It also turned quite piss to golden yellow at neutral, likely indicating more released bromine I guess.

I split the batch in two and added some NH4NO3 to one batch and nothing to the other, and put both in glass mason flasks in a sandbath at between 45-55C.

I let them sit only three days, and noticed in both flasks, but significantly more so in the one without NH4NO3 added, that there was a white precipitate in both, but not appearing like m-state precipitate, but more like ammonia precipitate. Somehow crystalline almost.

A little bit of the precipitate in the flask without NH4NO3 added has a slight yellow tint.

08-03-2009, 08:06 PM
I got another quite interesting result.

I had done an extraction on 100 grams of dead sea salt, with aqua regia, and ether, and upon evaporation of the ether about 5? ml of a light to forest green liquid remained.

I took it and added ammonium chloride. Quite a lot by volume actually.

I put it in a 100 ml brown glass glask and set it in a sand bath for 8 days.

I took the liquid out, leaving the remainder of ammonium chloride crystals behind that had crystallized out of solution again (and I added water to see if it they would dissolve which they did showing they were probably just the ammonium chloride), and added ammonia, a total of 15 drops, to get the pH to exactly neutral. (This can be done by sight, the first 10 drops lots of ammonia fumes come off, then drop by drop measuring pH until it's neutral.)

Right when I hit neutral, a significant amount of white precipitate appeared, so much in fact that the liquid was all white precipitate, and I was thinking: "I gotta add distilled water, so much precipitate for so little liquid"

So I add distilled water, and everything dissolved.


I added ammonia. No precipitate.
I added vinegar. No precipitate.

It appeared to have dissolved in water, but precipitate out of the water at neutral pH if the water is saturated with salt somehow.

I got a lot of precipitate, a ton more than the mere few snowflakes I saw previously as mentioned in the above post.