Reagent Alcohol and methanol: Danger?

[Beejis60]

!!

*Grabs popcorn and anxiously waits for his response*

I lol'd. Is it still hot?

I think Beej is an organic chemistry grad student, Catchol. Take it easy on him.

Not only a grad student, but one with 6 years of synthetic organic experience doing his own **** (3 years undergrad, 2 years MS, 1 year Ph.D.)

You're clearly *NOT* a chemist. Have you never heard of a molecular sieve?

Go sell some supplements...

Nope, no chemist here. I've never heard of or seen or used mole sieves either. Nor do I know how to activate them with a vacuum oven. And I did not know that they can be reused either.

We have 99% ethanol -- it's for high-precision (GCMS/FTIR) analytical work. Then again, we're an organic chemistry lab, not bio...

GCMS doesn't need high-purity solvents just as long as the chemical company didn't get any high-boiling impurities in there like those cock suckers did with my petroleum ether and DCM Usually diethyl ether is used the most because it's virtually 100% clean in its "lowest grade" directly from the company.
And who uses IR nowadays anyway? I only have to do it when I make a new compound because it's required when publishing. But more importantly, why do you need solvents for IR? Preferrentially, the sample should be placed neat on the salt plate then scanned to rectify the the gass(es) that's dissolved into the solvent such as CO2 and, sometimes, CO. Moreover, using EtOH can cover up any absorbances shown for alkene and alkyne stretching above the 3000 wavenumber mark; something like diethyl ether on the other hand will only have the CH stretches around 2800 or 2900 wavenumbers, I believe.

Let me clarify then...

In our lab (pharmaceutical research in an academic setting), we produce our own analytical-grade ethanol by passing CaO-dried (>95%) EtOH through a column of 3A zeolite molecular sieves. We have found this to be the most cost-effective way to obtain uncontaminated absolute ethanol for our frequent (daily) analytical (GCMS/FTIR) work and animal experiments.

Alright, couple problems here; one, CaO needs to be freshly ignited, but can hit up to 99.95% dry after distillation, if you're the ****. Two, no need to pass this EtOH through a mole sieve column because it's already dried and would cause more problems than benefits, however I would distill it over Ar and collect over mole sieves in case you store it in a simple RBF or 100mL container of sorts. You can also use CaH2 for distillation purposes as it's easier to work with than CaO (which is what I've used for drying deuterated methanol and ethanol).

The assertion that only one process exists for the production of absolute ethanol, or that absolute ethanol is ubiquitously contaminated with benzene, is exceptionally sophomoric.

Since everyone was talking about buying the ****, that's why I stated what I did because the chemical companies do to make absolute ethanol and through the reiteration of your post, you never mentioned making your own. The assertion of you assuming that I only assert that one process exists for PRODUCTION of absolute ethanol is actually true; most, if not all, chemical companies do manufature (or produce) their absolute ethanol through azeotroping with benzene. However, the assertion of you assuming that I only assert that one process exists of PURIFICATION for anything is completely false, hence the reason for me saying it's "made"..... This is also the reason why I own Purification of Laboratory Chemicals by Armarego and Perrin.

[Bioteknik]

That stuff is still "made" by azeotroping with benzene to remove the water.

I'll take what the Cof A states over a random poster on bb.com.

[alaska21]

I lol'd. Is it still hot?



Not only a grad student, but one with 6 years of synthetic organic experience doing his own **** (3 years undergrad, 2 years MS, 1 year Ph.D.)



Nope, no chemist here. I've never heard of or seen or used mole sieves either. Nor do I know how to activate them with a vacuum oven. And I did not know that they can be reused either.



GCMS doesn't need high-purity solvents just as long as the chemical company didn't get any high-boiling impurities in there like those cock suckers did with my petroleum ether and DCM Usually diethyl ether is used the most because it's virtually 100% clean in its "lowest grade" directly from the company.
And who uses IR nowadays anyway? I only have to do it when I make a new compound because it's required when publishing. But more importantly, why do you need solvents for IR? Preferrentially, the sample should be placed neat on the salt plate then scanned to rectify the the gass(es) that's dissolved into the solvent such as CO2 and, sometimes, CO. Moreover, using EtOH can cover up any absorbances shown for alkene and alkyne stretching above the 3000 wavenumber mark; something like diethyl ether on the other hand will only have the CH stretches around 2800 or 2900 wavenumbers, I believe.



Alright, couple problems here; one, CaO needs to be freshly ignited, but can hit up to 99.95% dry after distillation, if you're the ****. Two, no need to pass this EtOH through a mole sieve column because it's already dried and would cause more problems than benefits, however I would distill it over Ar and collect over mole sieves in case you store it in a simple RBF or 100mL container of sorts. You can also use CaH2 for distillation purposes as it's easier to work with than CaO (which is what I've used for drying deuterated methanol and ethanol).



Since everyone was talking about buying the ****, that's why I stated what I did because the chemical companies do to make absolute ethanol and through the reiteration of your post, you never mentioned making your own. The assertion of you assuming that I only assert that one process exists for PRODUCTION of absolute ethanol is actually true; most, if not all, chemical companies do manufature (or produce) their absolute ethanol through azeotroping with benzene. However, the assertion of you assuming that I only assert that one process exists of PURIFICATION for anything is completely false, hence the reason for me saying it's "made"..... This is also the reason why I own Purification of Laboratory Chemicals by Armarego and Perrin.

That was actually really interesting to read! Repz

[Beejis60]

I'll take what the Cof A states over a random poster on bb.com.

Are you calling me a random poster?

[alaska21]

Are you calling me a random poster?

Lol if someone with 7 years research experience +multiple degrees is a random poster I don't even wanna think what I am since I am an undergrad LOL

[Beejis60]

Lol if someone with 7 years research experience +multiple degrees is a random poster I don't even wanna think what I am since I am an undergrad LOL

You would be a brotological NINJA MASTER!!

[alaska21]

You would be a brotological NINJA MASTER!!

Yep LOL

[Bioteknik]

Are you calling me a random poster?

sure.. aren't we all?

Since it's now been determined that you are a subject matter expert, how much benzene remains in the ethanol then?

[tilebreaker]

Well, I'm not an organic chemist (cell bio/neurosci Ph.D. +6 yrs) so I won't get into the above debate, but here's the label for our "absolute" EtOH:

Pharmaco-Aaper
Ethyl Alcohol
200 Proof, Absolute, Anhydrous
ACS/USP Grade

Cat No: E200

Methanol <0.001%
Benzene <1ppm (which, depending on your point of view could be very little or way too much).



Edit: Yes, I'm that bored on a Friday afternoon...

[Beejis60]

sure.. aren't we all?

Since it's now been determined that you are a subject matter expert, how much benzene remains in the ethanol then?

A residual amount. Since they're miscible, you cannot really seperate them except by distillation and that, itself, is tough because benzene boils at 80C (if no water is present and subsequently not forming an azeotrope) and EtOH is 78C if I remember correctly. There really is no way to tell how much is in there, though I do know that it's enough that you do not wanna drink the ****; I know you can drink the "regular" ethanol though I still wouldn't do it

[Beejis60]

Well, I'm not an organic chemist (cell bio/neurosci Ph.D. +6 yrs) so I won't get into the above debate, but here's the label for our "absolute" EtOH:

Pharmaco-Aaper
Ethyl Alcohol
200 Proof, Absolute, Anhydrous
ACS/USP Grade

Cat No: E200

Methanol <0.001%
Benzene <1ppm (which, depending on your point of view could be very little or way too much).



Edit: Yes, I'm that bored on a Friday afternoon...

That's about 1 microliter per liter which is still more than I would like to drink though I probably inhale more than that per year between random people's cigarette smoke and just evaporation..... It's going about 1mL MeOH per liter which isn't too bad either, sounds like this isn't the "normal" ACS reagent grade but the label says otherwise...

[Catchol]

GCMS doesn't need high-purity solvents just as long as the chemical company didn't get any high-boiling impurities in there

...and how much pharmaceutical work have you done? When you've applied and received NIH grant money for IND research, then you can talk to me about the importance (or lack thereof) of solvent purity in pharmaceutical research. Maybe "good enough" makes the grade in supplement R&D, but it sure as hell doesn't cut it in drug research.

And who uses IR nowadays anyway?

We do.

But more importantly, why do you need solvents for IR?

Nice try, but I'm sure as hell not going to be giving away anything to you, at least not this easily...

Preferrentially, the sample should be placed neat on the salt plate then scanned to rectify the the gass(es) that's dissolved into the solvent such as CO2 and, sometimes, CO. Moreover, using EtOH can cover up any absorbances shown for alkene and alkyne stretching above the 3000 wavenumber mark; something like diethyl ether on the other hand will only have the CH stretches around 2800 or 2900 wavenumbers, I believe.

Blah blah blah.

Alright, couple problems here; one, CaO needs to be freshly ignited, but can hit up to 99.95% dry after distillation, if you're the ****. Two, no need to pass this EtOH through a mole sieve column because it's already dried and would cause more problems than benefits, however I would distill it over Ar and collect over mole sieves in case you store it in a simple RBF or 100mL container of sorts. You can also use CaH2 for distillation purposes as it's easier to work with than CaO (which is what I've used for drying deuterated methanol and ethanol).

We do things this way for a reason. If you don't agree with it, then I invite you to never work in our lab.

This is my last reply. I have no interest in continuing this discussion...

[alaska21]

When you've applied and received NIH grant money for IND research, then you can talk to me about the importance (or lack thereof) of solvent purity in pharmaceutical research. .

Whats NIH grant money have to do with anything...I know of UNDERGRADS who have been fully funded by NIH for independent research..


Regardless..FUN science fights! LOL

[Beejis60]

...and how much pharmaceutical work have you done? When you've applied and received NIH grant money for IND research, then you can talk to me about the importance (or lack thereof) of solvent purity in pharmaceutical research. Maybe "good enough" makes the grade in supplement R&D, but it sure as hell doesn't cut it in drug research.

I don't do supplement R&D, I do enyne metathesis in natural products, which happens to have pharmaceutical applications, tyvm.

We do.

For what? To see if you formed a carbonyl? An alcohol? An elimination product? That's about as good as it gets for organic chemistry. The inorganic people use it all the time and it's much more useful, from what I hear, than what it is useful for in organic chemistry.

Nice try, but I'm sure as hell not going to be giving away anything to you, at least not this easily...

Lol, what? You think I'm trying to "steal" **** from you or something? That's pretty awesome

Blah blah blah.

What happened to your smartass rebuttals? Or is that because you don't have one?

We do things this way for a reason. If you don't agree with it, then I invite you to never work in our lab.

I'm posting a PDF of the purification book I have, go ahead and look it up and see what they say. I know there's more than one route to most things, I'm just curious as to why you do that; you're just doing a lot of work for something that is so rediculously hygroscopic that it will just get wet the instant it touches air even if you actually do NEED it so dry. I think the only way to keep it dry is by distillation to a stopper RBF over mole sieves and use it in a glove box which is what I do for the d4 MeOH and the d6 EtOH.
So in academic research, which is what I am doing, you work for a prof, who do you work for? I work for Steven Diver.

This is my last reply. I have no interest in continuing this discussion...

Why? No need to get all worked up over something on here, which is pretty obvious.

EDIT: the PDF is too big, so I just copied and pasted from the PDF into word.

[scottymac710]

In all actuality, they are not that bad despite the warnings. However, when you said it burned like hell when you spilled it, did you happen to spill it on your clothes or just on bare skin or on latex-type of gloves?

all of the above lol i meant it burned when you got it on your skin tho .. it would deteriorate the latex gloves so they would break apart under any pull or pressure, didnt do much to clothes that i noticed

[Bioteknik]

That's about 1 microliter per liter which is still more than I would like to drink though I probably inhale more than that per year between random people's cigarette smoke and just evaporation..... It's going about 1mL MeOH per liter which isn't too bad either, sounds like this isn't the "normal" ACS reagent grade but the label says otherwise...

That's not what those mean at all, it means that those impurities were below the limit of detection.

[Beejis60]

all of the above lol i meant it burned when you got it on your skin tho .. it would deteriorate the latex gloves so they would break apart under any pull or pressure, didnt do much to clothes that i noticed

Hmm, weird. The only thing I notice is if I get chemicals on my clothes or get DCM and/or THF on gloves but I don't think I've ever experienced chemical burns via "direct" skin contact.

That's not what those mean at all, it means that those impurities were below the limit of detection.

Yes, but simple math translates to those numbers I posted.

[alaska21]

I never imagined my simple lab question would turn into such a heated debate on who is the best chemist on BB.com LOL

[Bioteknik]

Yes, but simple math translates to those numbers I posted.

There is a possibility, but the number posted means that it was undetectable.

[Bioteknik]

I never imagined my simple lab question would turn into such a heated debate on who is the best chemist on BB.com LOL

honestly.. use IPA then..

which then brings up the topic.. why are you using something that has limited efficacy, no antiviral properties, and won't kill spores? ;-)

[Beejis60]

honestly.. use IPA then..

which then brings up the topic.. why are you using something that has limited efficacy, no antiviral properties, and won't kill spores? ;-)

India Pale Ale




(that face indicates I know what IPA is, I'm just being a smartass)

[alaska21]

honestly.. use IPA then..

which then brings up the topic.. why are you using something that has limited efficacy, no antiviral properties, and won't kill spores? ;-)

lol when you have a good aseptic technique like me you don't need something that powerful

[Bioteknik]

lol when you have a good aseptic technique like me you don't need something that powerful

That's what they all say!

Ha.. we don't even get that option in federally regulated labs.

[alaska21]

That's what they all say!

Ha.. we don't even get that option in federally regulated labs.

Yeah my lab is just a college lab so definitely different regulations and standards

[PopeGregorius]

The assertion that only one process exists for the production of absolute ethanol, or that absolute ethanol is ubiquitously contaminated with benzene, is exceptionally sophomoric.

He didn't say that.