[Gray Wolf]

Originally Posted by RitualDelFuego

Sure. So we will refrain from pouring any on our morning pancakes.

I notice all isomers boil off below 170F which leads me to believe a very amount of ethanol and a diligent use of a vacuum oven might be all it takes to make it clean

the HHO i made last week seems fine , purged 48hrs in the spool then another 24 in an oven at 40C and hard vac

I try to avoid solvents identified to be a carcinogen, mutagen, or teratogen altogether, because medicating with it is a chronic exposure, and I'm uncomfortable with what that might do over time.

Attached is the FDA solvent standard list, giving the minimum levels it should be removed to as 2.9 mg/day or < 290 ppm, and placing Hexane (S) in the Class 2 group, which says:

Solvents in Class 2 (Table 2) should be limited in pharmaceutical products because of their inherent toxicity.

PDEs are given to the nearest 0.1 mg/day, and concentrations are given to the nearest 10 ppm.

The stated values do not reflect the necessary analytical precision of determination. Precision should be determined as part of the validation of the method.

We've had our best results purging n-Hexane, using ethanol and cold boiling it away under vacuum.

Hexane smells and tastes like gasoline, and most people can detect it at around 130 ppm, with trained threshold perception around 22 ppm.

If you can't smell or taste it, with average sensory perception, it is ostensibly below those levels.

[JamesFarmer]

I still have visible scars from my last chemistry class 30+ years ago....

[Old Gold]

Originally Posted by JamesFarmer

I still have visible scars from my last chemistry class 30+ years ago....

Care to explicate?
I've seen someone hand over a hot metal rod by the heated end, after removing from a Bunsen burner. So injuries are injuries, not inherent faults in the solvent/reagent use.
Scars from what? Hexane fume inhalation?

[corky1968]

I can't wait to try this Hexane stuff as I find butane and pentane too dangerous for nothing

I found a reasonably pure source of OTC N-Hexane.
I'll be cleaning it up with a separatory funnel that I
still have to buy and my glass still once I get going.

I'm even looking at getting a soxhlet extractor.
I'm going to run a second condenser on top to
really make sure no N-Hexane escapes at any time.

I'll be recycling and repurifying my N-Hexane at
each usage to avoid wasting it and cutting costs.

[Gray Wolf]

Originally Posted by corky1968

I can't wait to try this Hexane stuff as I find butane and pentane too dangerous for nothing

I found a reasonably pure source of OTC N-Hexane.
I'll be cleaning it up with a separatory funnel that I
still have to buy and my glass still once I get going.

I'm even looking at getting a soxhlet extractor.
I'm going to run a second condenser on top to
really make sure no N-Hexane escapes at any time.

I'll be recycling and repurifying my N-Hexane at
each usage to avoid wasting it and cutting costs.

Pentane is still liquid until around 36C/97F, so not in the same category as Methane, Ethane, Propane, and Butane.

Hexane is the next simple Alkane after Pentane, which sadly our livers turn into 2.5 Hexanedione.

https://en.wikipedia.org/wiki/Hexane-2,5-dione

That makes it imperative that it be purged below FDA standards for Pharmaceuticals. Note that Hexane is a Class 2 solvent, while Pentane is a Class 3 in the attached list.

[corky1968]

Originally Posted by Gray Wolf

Pentane is still liquid until around 36C/97F, so not in the same category as Methane, Ethane, Propane, and Butane.

Hexane is the next simple Alkane after Pentane, which sadly our livers turn into 2.5 Hexanedione.

https://en.wikipedia.org/wiki/Hexane-2,5-dione

That makes it imperative that it be purged below FDA standards for Pharmaceuticals. Note that Hexane is a Class 2 solvent, while Pentane is a Class 3 in the attached list.

I know about Pentane. But when the average room temperature is 20-25°C already.
It's doesn't give you much leeway before things start boiling. Also to purify it from
an OTC substance that I can get would take a lot more work.

This why I'm going with my OTC N-Hexane source.

Although, I'll probably purify some N-Pentane anyways later on to say I have some as well.

[einsteinlady]

If you are rotovaping hexane under vacuum what temperature would you set water bath to?

[Gray Wolf]

About 25C.

[G.O. Joe]

Depends on the condenser load which depends on all the other variables. And maybe your desire to keep low boilers in the extract. Both the evaporator and condenser are set for the temperature where all the condensation is in the first 2/3 of the condenser, given whatever you've got going on especially vacuum-wise. If you have a vacuum controller and enough vacuum it depends on your ability to condense.

[Gray Wolf]

Originally Posted by G.O. Joe

Depends on the condenser load which depends on all the other variables. And maybe your desire to keep low boilers in the extract. Both the evaporator and condenser are set for the temperature where all the condensation is in the first 2/3 of the condenser, given whatever you've got going on especially vacuum-wise. If you have a vacuum controller and enough vacuum it depends on your ability to condense.

Good point, all systems are not created equal,

If you max out your chiller and flow to the condenser, you can tweak the temperature up or down to keep the vapor 2/3rd up the condenser.