Hi all,

As you can gather from the thread title, my 2L borosilicate erlenmeyer broke during the last pull of a dmt extraction (this was a month or two ago now, didn't get around to make a post before). Luckily, I was performing the procedure in my garage instead of my kitchen, and I had a bucket of water at the ready which I quickly dumped the leaking flask into.
A small piece of glass had popped out of the bottom, luckily the whole thing didn't shatter on me, and there was not too much cleanup work. I was also wearing safety goggles and gloves, so no harm was done.

As you can imagine I was quite taken aback how my sturdy-looking flask broke while performing its first extraction. I have to add that I do not have much free time, so the base soup had been sitting in the flask for over a month, pulls were done once every weekend. Is it possible that such prolonged exposure to highly basic liquid could have etched and weakened the glass? I was under the impression that would not be the case?
I also have to add that I used a magnetic stir bar in the initial steps, and I did not have a magnetic rod to remove it back then, so I left it in there, and have shaken the flask quite heavily multiple times before each pull (I used Cyb's Max Ion and I guess the salt did a good job preventing emulsions as it was very liquid and separated very well no matter how hard it was shaken). The stir bar is teflon coated, and I wouldn't think it could really damage the thick glass. Maybe I also did not vent pressure fast enough, and the combination of factors (prolonged exposure to highly basic liquid, the stir bar knocking against the glass and not venting pressure enough) eventually cracked the weakest point of the flask? Maybe it was solely extreme built up pressure that did it? I'm really not sure.

Now that I have a rod to remove the stir bar, I won't be leaving it in anymore, and I will also pay careful attention to release pressure far quicker.
However, I still wonder what effect the prolonged exposure to basic liquid really has on the glass. Can anyone chime in and put my mind at ease? I want to purchase a new 2L flask for a next extraction, and would like to hear about this before I proceed with further experiments. I'm afraid I have no alternatives to letting the liquid sit for a long time, I really cannot perform the procedure in just a few days.

It's a good thing that you had good personal protection and extra precautions in the formn of the bucket in place. Well done!

Room temperature lye solution, even quite concentrated, will at most etch borosilicate glass superficially. It might leave your previously shiny glassware frosted. If there is no sign of frosting, you can discount the lye as a source of failure. It is true that you can dissolve glass in molten anhydrous lye at temperatures over 300 degrees Celsius, but such conditions do not apply to extraction operations.

Hitting glass, especially repeatedly, with hard objects is asking for problems. Even though the stirbar has a teflon coating, forcefully shaking and banging it against the glass can cause cracks or exacerbate existing cracks in the glass.

Was your glassware bought new or was it acquired as a second hand item? New quality glassware should be able to withstand some abuse, but after severe local heating and heat shocking the glass may become internally stressed and would be more vulnerable to mechanical shock. Glass may be micro-cracked from mechanical impact and it can be hard to see the damage without the aid of dedicated tools.

Out of curiosity, what brand was it?

all lab glass dies badly.

that leaves only 1 question.........
did you order 3?


oh , and never trust lab glass.
ever.

stir bar.
dont do that.

Also, how vigourously were you shaking it?

I've never had problems with a 2L pyrex with basified solution and a stirbar. granted, it's a heavy-wall erl.

just don't store concentrated basic solution in glass, long-term. sodium hydroxide forms sodium silicate with glass, over time..this process is accelerated with heat.

Yes, I will not be doing that again in the future, that's for sure!




As far as I know it should be new. I got it from a brewing store (along with some beakers, measuring cylinders, etc. All seems quality material as far as I can tell). The store mentions that all their glassware is quality labware, and that it is heat-resistant borosilicate glass.



It was produced by Simax in Europe (Czech Republic to be specific). I've added some pictures to my original post to give a better idea of the thickness and quality of the flask, and the damage done.



I was alternating between tumbling the flask end over end and, swirling it in a rolling motion while holding it sideways and shaking it fairly hard. And yeah, I heard the stir bar knocking against the bottom with every shake, although I was sure it wouldn't do any damage. I guess it was most likely the combination of slight etching from long term lye exposure, the furthering of damage by shaking with the stir bar, and possibly not releasing pressure in the most timely manner while shaking.



Thanks for the explanation. Are there any alternatives for longer-term storage that you can suggest?
The only thing I could think of would be HDPE plastic (rather not), or just a disposable large, thick jar so I can wear that out slowly while storing the solution instead of the lab glass which has to be worked with..
I assume that any possible sodium silicate will not end up in the final product if one or more re-x's are done?

Why on Earth do you say that? I've worked in 3 different chem/biochem labs in my life and 1) stir bars have been very useful and never a problem and 2) the only time I've known lab glass to break is when it's mishandled.

As for the OP - as a general rule of thumb, it's not great to store things in solution for long periods of time, esp. if it's reactive. I can't say that it was exposure to the base that compromised your glass, but in general, it's good to get things into a solid phase for storage.

Blessings
~ND

35 yrs of clan labs and 12 yrs defense contracting lab, almost a decade of college,
mostly in the sciences...........

never trust glass, and, dont shake with mag stir bars.
ive seen the best of the best explode .

benz is right, some stuff slowly degrades glass.
mileage varies.

ill suggest if your glass is featured on " antique road show"
your not an alchemist.
broken glass isnt good , but it sure measures progress!

oh, and break it good before disposal.
the proles are very frightened by chemware they discover in dumpsters.

i buy everything by the case.
and expect to lose it all sooner or later...............
no love, glass is a cold blooded animal.


* note
close review the punch out from the stir bar is signature.
when i was a little girl i blew out a few the same way........

Thanks for posting this. 2L erlenmeyer has been my staple extraction vessel and I have often thought "heck, it's lab glass" and taken a few liberties.

I think I'll be more careful now and better with PPE....

not even a re-x, just filtration in a solvent the alkaloids are soluble in. long-term storage of basic solution in HDPE is fine.

know thy glass.
but
also know thy plastics............

know thy intermolecular interactions.
generally speaking: polymers (plastics) are largely nonpolar, like dissolves like...thus, nonpolars dissolve polymers (depending on the polymer and solvent).

most polar solutions do not dissolve plastics.

Which is why hydroflouric acid doesn't dissolve plastic, but can dissolve glass.


Keeping clean and maintained glassware is imperative for any lab. Always store chemicals in the proper containers. If you do store basic solution, get the sturdy HDPE containers.


This is what I use.

I've used HF, to etch fused silica.. in a PTFE vessel.