[HN Gopher] How to Clean Chemistry Glassware
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How to Clean Chemistry Glassware
Author : adrian_mrd
Score : 30 points
Date : 2023-12-14 06:58 UTC (16 hours ago)
(HTM) web link (www.chem.rochester.edu)
(TXT) w3m dump (www.chem.rochester.edu)
| getwiththeprog wrote:
| Finally got the dishes done properly today, thanks Rochester!
| showerst wrote:
| It's interesting to me how concentrated HF is just universally
| acknowledged as one of the 'big bads' of chemistry labs.
|
| I've run into "Yes HF works here but SERIOUSLY DON'T" in so many
| different contexts and processes. Sounds like a lovely thing to
| keep a nice distance from!
| cgearhart wrote:
| It makes the list of Things I Won't Touch
| https://www.science.org/content/blog-post/things-i-won-t-tou...
| purpleflame1257 wrote:
| Acidic peroxide solution is also known commonly as piranha
| solution. You can clean silicon wafer by dropping them in. Any
| organic residue is toast, however.
| foobarian wrote:
| Sounds enticing for cleaning burned baking dishes! I tried with
| concentrated NaOH and that didn't work so I need more extreme
| solutions.
| cowthulhu wrote:
| That seems like a terrible idea on many levels. Will
| definitely make for some fun anecdotes though (assuming
| nothing goes wrong). Also - I don't know if I'd want to eat
| anything cooked on a baking dish exposed to so many toxic
| chemicals.
|
| I assume you're not joking, but this was a major whoosh if
| you were!
| jeffbee wrote:
| Depending on what the material is, you can potentially clean
| it by burning it harder. Set your over to 'clean' and find
| out.
| rubicks wrote:
| Ex-undergrad-assistant in a organic synthesis lab, here. I am
| extremely familiar with glass cleaning procedures, having done it
| nearly daily for one long semester.
|
| Base bath is how you clean glassware.
|
| The base bath was a _saturated_ solution of KOH (potassium
| hydroxide) in a 10-gallon PTFE (molded "teflon"). You knew it was
| saturated by the KOH precipitate at the bottom.
|
| You take your "dirties", making absolutely sure they had no
| residual acid on them, and ever so slowly, ease them into the
| bath. 24 or 36 hours later, remove them and repeat with the next
| batch.
|
| After a few dozen cycles, you have to change out the base for
| fresh stuff. For that, you needed a face shield, shoulder gloves,
| and extremely steady hands.
|
| Tedious, dangerous work.
| kragen wrote:
| why can't you siphon the base bath instead of having extremely
| steady hands
|
| i'm also sort of surprised this treatment doesn't corrode the
| glass. i guess borosilicate holds up to things that would ruin
| soda-lime glass
| jmwilson wrote:
| Using Alconox (mentioned on the page, and easily found on Amazon)
| is one my tricks when I absolutely need sparkling clean dishes or
| containers. Not the best choice for the environment, and too
| sudsy to use in a dishwasher, but amazingly effective.
| jeffrallen wrote:
| Nile Red got into a situation where some of his glassware was
| damaged by a reaction but mixed into his still good glassware. He
| decided to break it all to be sure!
|
| That's another cleaning strategy.
| gizmo686 wrote:
| https://youtu.be/tGqVMbAQhBs?si=FAve6HjtEd9rjbZv
|
| Notably, his concern was not that the glass was dirty, but that
| it was literally breaking. As in, spontaneously spill a beaker
| full of acid on the table breaking.
|
| The experiment he blames this on was using the beakers to
| contain hot plasma. The beakers came out looking fine, but
| probably suffered substantial thermal stress.
| jeffbee wrote:
| Frustratingly familiar from my college days is the vagueness of
| these instructions. "Wear appropriate gloves." Such as? It is
| easier to write "wear butyl gloves." Even the MSDS for 6M HCl
| doesn't say "wear butyl gloves" it says "Select glove material
| impermeable and resistant to the substance." Like, duh. Is there
| a PPE lobbyist who prevents people from writing down concrete
| recommendations?
| somat wrote:
| A good point, a very good point. Too many procedures or guides
| are ruined by being vague on some minor yet critical point.
| Probably obvious the the writer but not to the reader.
|
| However I will note this guide specifically points out to use
| butyl gloves twice.
| gorlilla wrote:
| Because recommendations will vary by not only currently
| accepted practices, but also geographical variances in product
| availability. It's better to look at what you have on hand and
| cross-reference with up-to-date information.
|
| Much like most people won't simply know how dangerous it is to
| mix Nitrile gloves and Nitric Acid. When things can melt your
| skin, it's always good form to verify safety info at the time
| rather than just taking somebody's word for it, no?
|
| My 2 cents that is probably obvious anyhow
| jeffbee wrote:
| Nitrile gloves are quite useless against many common
| substances, including acetone, esters, acetic acid, and
| everything else with "acet" in the name. Aside from a few
| cases where nitrile works and others don't (some
| hydrocarbons, among others), there's usually something more
| protective.
| eternityforest wrote:
| For non chemists just working with standard commercial
| stuff(Epoxy, UV resin, grocery store cleaning chemicals,
| and that's about it), various sites and ads give the
| impression nitrile is "The good default thing you should
| use"....
|
| Good to know that's not always the case?
| onecommentman wrote:
| Why isn't lab glassware, with few exemptions, a single use item?
| How can the human safety risks in cleaning, and the analysis
| risks from residual contamination be valued less than the cost of
| fresh equipment made of...glass. Really nice glass, but simply
| mass-produced objects made of silicon and oxygen. Just make some
| more.
|
| The 1970s _Muppet Show_ US television program had a recurring
| segment on "Muppet Labs" with a hapless lab assistant named
| Beaker given silly and dangerous things to do by his boss. These
| cleaning processes sound like a Beaker bit. But the Muppet Show
| was a comedy...
| gizmo686 wrote:
| If you are working in a lab that needs that level of cleaning,
| then odds are that what you do with the glass when you use it
| is also dangerous. There is a reason that the stereotypical
| chemist wears gloves, goggles, and a labcoat.
|
| Also, lab glass is more expensive than it looks. If you care
| about this level of cleanliness, then you likely also care
| about the precision of your glassware. And lab glassware comes
| in much more exotic and hard to make forms than beakers. You
| also might not be able to throw it away in the normal trash
| because it is contaminated with something hazardous.
| jmwilson wrote:
| A lot of it is not mass-produced
| (https://www.latimes.com/local/education/la-me-caltech-
| glassb...). Even if you used brand-new pieces, for analytical
| work, you'd still need to clean them according to these
| procedures to remove residues from manufacturing, storage, and
| shipping.
| montecarl wrote:
| Because laboratory glassware is very expensive and that would
| be massively wasteful? Also, most labs that I have been in make
| regular use of custom made glassware. Most chemistry
| departments employ a glassblower! Also, for very sensitive
| experiments, you would most certainly want to clean even brand
| new unused glassware.
|
| Glass is amazing for chemistry not only because it is
| chemically inert, transparent, has a high melting temperature,
| and is reasonably strong but also because it is easy to clean!
| mmaunder wrote:
| In case anyone else wanted to cut to the chase - as in, what is
| the most badass, dangerous, corrosive and potentially deadly
| cleaning method:
|
| _Hydrofluoric: Concentrated solutions of HF will remove just
| about everything from glass and will even etch the surface of the
| glass itself. It should not be used on calibrated volumetrics. HF
| causes severe, painful burns that do not heal well, and prolonged
| or intense exposure can lead to a very slow, painful death. It is
| not to be used by any students at Truman under any
| circumstances._
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