Piranha is my favourite for stubborn organic residues but it needs to be made and used fresh. I think the difference between the base baths you mentioned is negligible and largely dependant on what you're trying to remove.

https://www.youtube.com/watch?v=mk72x1NYQXU

There's probably much more dissolved hydroxide (and alkoxide) when using ethanol, so I would not be surprised if it were more efficient.  If your contaminants are very hydrophobic, however, you might find that isopropanol is still superior. As Phillip notes, it depends on what you're trying to remove.

(In the bad old days, we all had chromic acid jars by the sink - we liked that it didn't etch the glass, but I shudder to think of how much chromium we sent down the drains!)

EtOH / NaOH

EtOH / NaOH

Under certain circumstances the EtOH/NaOH is able to attack glassware, I'd rather prefer a EtOH/KOH solution, as usual, the fresher the stronger.

Well, we use iPrOH/KOH in the lab and it did a good job! In case you couldn't remove a chemical from glassware, nitric acid can be used.

Currently this one (recipe at the end of pdf):

http://bnorthrop.faculty.wesleyan.edu/files/2009/09/CleaningGlassware.pdf

Works well.

Well, but many time we uses conc. sulfuric acid with potassium dichromate .

There will  be a little/negligible difference between KOH-EtOH and NaOH-EtOH . I would rather use NaOH-EtOH.

Echoing the views of James, I would like to lament for draining so much of chromium in the drainage system in those bad old days. We cannot afford to doing the same now.

I usually soaked my glasswares in 2% Decon 90 overnight. It contain 0.5-2% KOH. And sometimes I filled my beaker with decon and sonicate them for about 30 minutes.

I usually washed my glasswares with boiling 2M NaOH and rinsed with distilled water but in the absence of the above chemical I would prefer to use 10% KOH.

I usually use a 1NaOH/IPA mixture and it has far worked well for me, especially if I leave my glassware soaked in overnight in a fume cupboard.

Dear Mr Linstadt, I think that besides alkalinity of the medium be important to remove fat, the surface tension is another relevant  factor. Ethanol has a surface tension equal to 22.1 mN m-1, while the surface tension of isopropanol is 23 mN m-1 , both measures at 20 ºC (http://www.surface-tension.de/). Hence, mixtures of bases with ethanol has major wettability. This is just a hipothesis that can explain the better efficient of NaOH/EtOH  in relation to KOH/ISPrOH. Kind regards.

I prefer IprOH/KOH

but EtOH /KOH IS more efficient than IprOH /KOH

I prefer KOH/I-PrOH.

IprOH/KOH

I prefer KOH/I-PrOH.

I personally think mixture of ethanol and KOH or NaOH is more preferrable than  ethanol and KOH  miixture since it has more wettablity,

I prefer KOH in isopropyl alcohol. But I personally use also bichromate mixture.

Sorry want to say preferable  to ethanol / i-PrOH. 

Personally, I prefer KOH with ethanol and water. Water was used to solute KOH, while the solution cooled down, ethanol was added. Hope that helps.

I prefer i-PrOH and KOH.

p

Thanks everybody for your input!

-RL

I use 10% water in EtOH as solvent and KOH (20% w/w)

Lower vapour pressure for isopropanol

It depends on what you want remove ..Ethanol/NaOH or KOH normally can be used . In certain cases nitric acid is also  effective .

Isopropanolat-Ion (CH3(CHO)CH3-) pKb=-3.1; Ethanolat-Ion (C2H5O-) pKb=-1.9

http://www.periodensystem-online.de/index.php?sel=abc&prop=pKb-Werte&show=list&el=1&id=acid

hey guys

which one is better to get rid of anions like sulfate from glasswares and sample tubes? acid bath or base bath?