goldberg - 13-11-2018 at 08:19
Happy occasion happened and i become owner of micropipette.
I read about them and basicly know how to use them and what to avoid except one thing:
solution of which solvents apart water i can pipette with it?
I do not want to damage precious mechanism. Manufacturer did not wrote anything about it.
Ofc. highly corrosive substance are out of question. But how about alcohols like ethyl or isopropyl alcohol or acetone? Or ethyl acetate and other
common solvents?
Metacelsus - 13-11-2018 at 08:45
I've used a micropipettor with chloroform before. I expect that it could handle many solvents. I would not use it for corrosive materials (acids,
ammonia, etc).
What's the model and manufacturer?
I_love_Diethylether - 13-11-2018 at 09:19
I already used it with Diethylether, Acetone and Isopropanol. I also would recommend not to use it with aggressive fluids. Additionally note that,
when working with Air cushion micropipettes, you will get a volume error with fluids that have a different vapor pressure than water (not much but
enough when you work in µL scale)
goldberg - 13-11-2018 at 13:53
I have accumax 5ml-0.5ml and accumax pro.
I am aware of problem of evaporating sample. I am worried much more about damaging pipette itself.
Thanks for pointing out ammonia.
Someone on Internet asked about chloroform escaping from sample in pipette tip but this is not good indication about solvent compatibility.
Isopropanol does not damage most of plastics. Acetone is definetly worse but i did not found any hits if i can or can not use acetone soultions with
this pippette. And how about ethyl acetate and hydrocarbons?
VSEPR_VOID - 15-11-2018 at 15:29
If you use tips than most things are fine, especially if you use filter pipette tips. I have used those little things for 4 years and never had a
problem.
In generation dont let anything get inside them and when not in use, adjust them so nothing is under tension
phlogiston - 15-11-2018 at 21:51
I've used them occasionally with many different organic solvents (including alcohols C1-C5, acetone, acetonitrile, diethyl ether,
methyl-tert-butylether, THF, DCM, chloroform, hexane, toluene) and the set of pipettes I regularly use still seems to work fine. They get calibrated
every so often and pass the tests.
99% of the time I use them for aqueous solutions though. Only now and then I need to pipet organic solvents.
The accuracy with most organic solvents is probably not very good though. The difference in viscosity, adhesion to the tip and the vapour pressure
pushing the solvent out of the tip. So, if you need to pipette organic solvents and accuracy matters, these types of pipettes are probably not the
best solution.
What helps with the vapour pressure issue of some solvents is to fill and empty the pipette tip a couple of times with the solvent you will be
pipetting. When the air inside the pipette gets saturated with the solvent vapours, it stops dripping out of the tip anymore, and you can pipette it a
little more accurately.
[Edited on 16-11-2018 by phlogiston]
VSEPR_VOID - 16-11-2018 at 07:13
I did not know that. I will keep that in mind the next time I am working with volatile materials.
goldberg - 17-11-2018 at 01:04
Thanks for replies. I have tips without filter and they seem to be high quality polypropylene ones.
phlogiston - 17-11-2018 at 13:43
With the tips, one thing that can be annoying is that not every brand of tips perfectly fits every pipette.
Even though they may seem identical, and the tip manufacturer states their tips fit certain pipette brands, still sometimes, there is a slight
difference in dimensions or tolerances, and you'll find that you have to press the tip on much harder than should be necessary to get an air-tight
seal.
It should not require much force to put a tip on or off.
And the pipette-tip seal should be consistently air-tight.
[Edited on 17-11-2018 by phlogiston]