Sciencemadness Discussion Board

GL45 Caps?

thors.lab - 11-12-2020 at 21:51

This is driving me crazy! I have two or three GL45 threaded bottles without caps. Online I can only find like 12 packs of GL45 caps selling for $80 total. Would anybody be willing to sell me just two used (or new) GL45 caps? Thanks!

Also, this is a long shot, but does anybody have something that fits on a GL45 and allows me to pump small amounts of liquid out? I'd like to be able to easily & quickly pump out just 1-5mL at a time or so of solvent for TLC or other small scale analysis.

[Edited on 12-12-2020 by thors.lab]

Sulaiman - 12-12-2020 at 07:06

Whenever I use a syringe or pipette to transfer volatile solvents
some liquid is usually forced out by the evaporating solvent.
I guess that this would be the case for many liquid transfer/delivery systems.

I mostly use 3ml disposable pipettes (in bags of 100=cheap)
Negligible contamination of solvent stock,
and if I allow a little air into the pipette just as it is withdrawn from the solvent bottle
and turn the pipette upside down while transfering the pipette
Usually no solvent escapes.

Not what you wanted but may help a little.

Dr.Bob - 12-12-2020 at 11:16

I have some white LF45 caps that are teflon lined, but not listed for high temps, but they are ideal for simple storage of chemicals. I sell them for $2 each, plus postage, and even have more 1l media bottles to go with them, should you need more. I might have a pump type dispensor, not sure if for those or what type of bottle, but I will look and see what I have. I used to have several, just need to find them. Send me a u2u for more info.

thors.lab - 14-12-2020 at 16:00

Quote: Originally posted by Dr.Bob  
I have some white LF45 caps that are teflon lined, but not listed for high temps, but they are ideal for simple storage of chemicals. I sell them for $2 each, plus postage, and even have more 1l media bottles to go with them, should you need more. I might have a pump type dispensor, not sure if for those or what type of bottle, but I will look and see what I have. I used to have several, just need to find them. Send me a u2u for more info.


Thanks bob, I sent you a message. I'll get back to your email ASAP!

thors.lab - 14-12-2020 at 16:03

Quote: Originally posted by Sulaiman  
Whenever I use a syringe or pipette to transfer volatile solvents
some liquid is usually forced out by the evaporating solvent.
I guess that this would be the case for many liquid transfer/delivery systems.

I mostly use 3ml disposable pipettes (in bags of 100=cheap)
Negligible contamination of solvent stock,
and if I allow a little air into the pipette just as it is withdrawn from the solvent bottle
and turn the pipette upside down while transfering the pipette
Usually no solvent escapes.

Not what you wanted but may help a little.


Yes you're right -- I have noticed this too. Especially with ACE in wash bottles -- that stuff will just randomly squirt out of my wash bottles and it's very frustrating! But my university does have some pumps that works with volatile substances. They have very fancy ones where you can actually dial in how many mLs you want down to 0.01mL and it will pump it out. I looked those up and found out they are nearly $1000. Wow! That's where my tuition is going... I was just looking for something much more basic with much less precision.

[Edited on 15-12-2020 by thors.lab]

Endo - 21-12-2020 at 09:30

Not sure of the prices but the capillary style microdispensers work well. They have a plunger that fits inside of a calibrated glass capillary tube. With no headspace inside the capillary between the plunger and the liquid you don't deal with the vapor pressure issues. A quick online search shows a company named Drummond that makes both fixed and adjustable volume ones. here