[lawrencek]

I have some gasoline that I have been processing. I need to check if it has water IN it - it has been rinsed with water and then dried.

I was going to try Cobalt Chloride paper but thought this would only with ionic solutions.
I tried mixing a little Na0H in and then trying Universal Indicator Paper and the water would be alkaline - no result.

I was going to try a water soluble dye and that might show.

My next try would be CuS04 anhydrous which would turn blue if water was there.

Any ideas?

Lawrence

[Hunter2]

CuSO₄ will also not work with the same argument CoCl₂ doesn't work. NaOH is not soluble in gasoline., So no reaction. If a reaction takes place then the gasoline is wet and also theother two should react.

[lawrencek]

I've got that right then, and about the CuS04.

I was going to try and measure the resistance, but probably that will only work if the water molecules are touching.

I was wondering if a water soluble dye would show up. I know there are test kits but I wanted to do it myself!

[lawrencek]

I am processing gasoline which has water in it. (I removed the alcohol with water first).

1: I wanted to dry the gasoline. I am using silica gel.
2: I want to test the gasoline for water in suspension.

These are my results for the water tests.

I tried to see if the SG was different if wet and natural gasoline. Could not use a beer Hydrometer as gasoline is not dense enough.

Tried to see if the dielectric constant was different - make it part of a tuned circuit immersed in the samples. A little different but need a multiplate capacitor in the sample.

If I put 30 cc on a metal tray and swill it too and fro, blowing on it or in a breeze, the gasoline evaporates and goes milky. The tray appears to show globules of water which slowly collect in streams.

The dried gasoline shows this effect much less showing that I am on the right track. Incidentally native gasoline also shows this effect showing that it contains water. This is easy to demonstrate.

I was going to test by shaking the wet gasoline with NaOH, decanting and then mixing with water (which would then mix with the NaoH already in solution) and then test with indicator paper.

Have I make the right conclusions?

Thanks

[lawrencek]

I confirm that the milky effect is indeed water.  Using the wet gasoline (having settled it) if i leave the gasoline to evaporate by swilling it around the creamy liquid moves like water does, and does not burn even when a match is dropped in it.

So it appears that although waser does not dissolve much in petrol I suppose, it can be held in suspension. And then it can.

[Arkcon]

The Solubility of Water in Gasoline and in Certain Other Organic Liquids, Determined by the Calcium Chloride Method.

http://pubs.acs.org/doi/abs/10.1021/ie50139a019

[Fakes]

If you add water to gasoline yoy'll see that gasoline does not mix with water. Water will go down. Contrary to diesel which "holds" water. For this reason there is a limit and a method for water in diesel and at the same time doesn't exist for gasoline in water.

[lawrencek]

I agree, but the wetted gasoline (mix with water settle and decant) still contains water in suspension according to my "milk test".

There is quite a bit there, so it may not be dissolved but is in suspension.

I could not burn the liquid that settled out.

I am going to try the Beilsteins test - mix some dry salt with the gasoline and leave to settle. Then the salt will dissolve in the water in the gasoline and do the test.

I am sure that the liquid that settles out is indeed water.

What do you think?

Lawrence

[Intanjir]

Centrifuge?