Hi everyone!
Just a quickie. The lab I am in measures the quantity of acetic acid and propionic acid in samples by G.C.
At the moment we are trying to accurately pipette the quantities using glass pipettes and fillers, which I hate, and find to be almost impossible to get spot on everytime. When I queried this, I was told we can't use mechanical pipettes because the chemicals we use 'screw them up'.
We use;
acetic acid
propionic acid
valeric acid
all diluted in a stock mixture of orthophosphate:diethyl-ether. Do I HAVE to use glass pipettes?
Also, the stock solutions we make up are kept in the fridge for 1 month, which I think is a bit too long with stuff like diethyl. Any thoughts on this?
Thanks for any help!!
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6 replies to this topic
#2
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Why does a science forum not have pictures of mice and rats?
Posted 05 July 2010 - 12:48 PM
Scoob00,
What about a repeater with a syringe? The acid will never touch the pipetter itself.
regards,
lab rat
What about a repeater with a syringe? The acid will never touch the pipetter itself.
regards,
lab rat
42..."An immutable fixed-precision number of unlimited magnitude." <a href="http://en.wikipedia.org/wiki/Python_(programming_language)" target="_blank">http://en.wikipedia.org/wiki/Python_(programming_language)</a>, accessed 25June2009.
#3
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Enthusiast
Posted 08 July 2010 - 04:31 AM
Hiya,
Thanks for your reply! Sorry to sound dense, but whats a repeater with a syringe?
Cheers!
Thanks for your reply! Sorry to sound dense, but whats a repeater with a syringe?
Cheers!
#4
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Why does a science forum not have pictures of mice and rats?
Posted 28 July 2010 - 12:41 PM
scoob00, on 08 July 2010 - 04:31 AM, said:
Hiya,
Thanks for your reply! Sorry to sound dense, but whats a repeater with a syringe?
Cheers!
Thanks for your reply! Sorry to sound dense, but whats a repeater with a syringe?
Cheers!
Sorry, I haven't been around in a while. Here's a link (I'm not endorsing either the brand or the vendor.)
http://www.thomassci...-Plus-Pipettor/
Edited by lab rat, 28 July 2010 - 12:41 PM.
42..."An immutable fixed-precision number of unlimited magnitude." <a href="http://en.wikipedia.org/wiki/Python_(programming_language)" target="_blank">http://en.wikipedia.org/wiki/Python_(programming_language)</a>, accessed 25June2009.
#5
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Somewhere I belong
Posted 28 July 2010 - 01:16 PM
LaRa is right. I think you could use any positive displacement pipette (the repeater is basically a positive disp) in which the piston is in the tip, so the liquid is never in contact with any permanent part of the pipette.
This one is from Gilson, they have some good explanation on their working
http://www.gilson.co...esourceTypeId=1
This one is from Gilson, they have some good explanation on their working
http://www.gilson.co...esourceTypeId=1
#6
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Hmmm, I think it's working
Posted 29 July 2010 - 01:56 PM
Actually, part of the problem is gases evaporating off the surface of the acid, which then corrode any metal parts and deplastinate the plastics.
If you are worried about small volumes, use a small glass plunger hamilton syringe, or make up a bigger volume.
If you are worried about small volumes, use a small glass plunger hamilton syringe, or make up a bigger volume.
#7
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Somewhere I belong
Posted 03 August 2010 - 06:32 AM
Hi Scoob00, Just saw this new kind of tips in a box of free test samples that I got last day and thought of your needs!
They are called Solvent safe carbon filter pipet tips...never used them myself...they claim its meant for acids, organic solvents etc
http://www.mbpinc.co...?query_TipId=85
yeah, the vapours would still be a trouble no matter whatever you use!
They are called Solvent safe carbon filter pipet tips...never used them myself...they claim its meant for acids, organic solvents etc
http://www.mbpinc.co...?query_TipId=85
Quote
Actually, part of the problem is gases evaporating off the surface of the acid, which then corrode any metal parts and deplastinate the plastics.
yeah, the vapours would still be a trouble no matter whatever you use!
