Sciencemadness Discussion Board

Cleaning brand new glass, is it necessary?

idk - 30-7-2018 at 04:13

If you buy new glass that is "opened" as e.g. beakers I assume you would want to clean the glassware first before any reaction.

Assuming you want to store Analytical Grade reagents in containers as Amber Glass bottles that are capped from the start is it obligatory to clean it too, or the seller cleans them for you?
If cleaning before use is needed then are detergents sufficient or it should be soaked in base and acid baths?

weilawei - 30-7-2018 at 05:08

Some sellers sell them pre-cleaned, and this is often expensive. Mostly, unless it's something with a certificate that it was cleaned (like my Nalgene FEP bottle came with one), I'll clean it quickly. For anything I'm worried about purity, I'll clean it and do a final set of rinses with the expected solvent or a cleanly evaporating one (often just distilled water).

diddi - 30-7-2018 at 15:16

i clean every item i use. every time. before use and again after use. always.
if it is appropriate to wash with reagent also, then i do so.
old school analytical training is hard to shake off

Sulaiman - 31-7-2018 at 01:37

For 'analytical grade' reagents you should clean the bottles
to at least the cleanliness expected of your analytical glassware.
Generally speaking, if water forms droplets on the glass rather than sheeting off,
then your glassware is not clean enough.

I believe that amateurs should use dirty glassware
as we are not likely to discover anything new using pure reactants and clean equipment :P



If you have 'analytical grade' chemicals I assume that they were supplied in a suitable container,
why do you want to use a different container/bottle ?

Herr Haber - 31-7-2018 at 04:37

Quote: Originally posted by Sulaiman  

If you have 'analytical grade' chemicals I assume that they were supplied in a suitable container,
why do you want to use a different container/bottle ?


Let's say... if I bought DCM from APC Pure it would come in HDPE.
Experience tells me if I leave it in HDPE it'll be gone when I need it.
I cant relate to analytical grade reagents though.

Also, I'm super cautious about gas evolution in my storage bottles and thoroughly clean everything to avoid unwanted reactions.
I'd need an endoscope to take a clear picture but I once had something *grow* from one wall to the other inside a nitric acid bottle.

lowtech - 1-8-2018 at 14:55

this matters only if you are performing a sensitive reactions first, but for regular reaction on a gram scale, it does not matter. it is obvious to see when glass isnt clean. from my experiences, there isnt much dirt on new glassware, but i give it a water wash, then some ethanol squirt to be sure, but i think it isnt necessary :)