Chromatography Forum

One of my test sample is viscous, I need 1 mL, 2 mL, 5 mL, 10 mL and 25 mL TO CONTAIN pipette, I have not found any vendor locally, do you any international brand for these pipettes?

Do you check the dispensed volume with a calibrated or class A volumetric? If so, you may be OK.
We have several prep methods that use this and QA is fine with it.
Yes, we are NELAC (TNI) certified.

Weighing a 1 mL volume of a volatile solvent (DCM or methanol) in a fume hood is not as quick as dispensing to a 1 mL vol flask.

Guess we will just clean out the re pipets and check them with water/mass quarterly!

I am ok with traceability, but I am afraid one day there will be auditors asking for the lot number of the toilet paper used to "maintain" the analysts the perform the tests.

“Oh, the jobs people work at! Out west near Hawtch-Hawtch there's a Hawtch-Hawtcher bee watcher, his job is to watch. Is to keep both his eyes on the lazy town bee, a bee that is watched will work harder you see. So he watched and he watched, but in spite of his watch that bee didn't work any harder not mawtch. So then somebody said "Our old bee-watching man just isn't bee watching as hard as he can, he ought to be watched by another Hawtch-Hawtcher! The thing that we need is a bee-watcher-watcher!". Well, the bee-watcher-watcher watched the bee-watcher. He didn't watch well so another Hawtch-Hawtcher had to come in as a watch-watcher-watcher! And now all the Hawtchers who live in Hawtch-Hawtch are watching on watch watcher watchering watch, watch watching the watcher who's watching that bee. You're not a Hawtch-Watcher you're lucky you see!”

From ― Dr. Seuss, Did I Ever Tell You How Lucky You Are?

Guess we will just clean out the re pipets and check them with water/mass quarterly!

This is what we implemented to satisfy NELAC auditors. It is a pain to flush out bottle top dispensers with water, dispense and weigh water, then switch them back to solvent, but it was the only way to avoid repeat findings It is not so bad for the Eppendorf/Rainin repeating pipettes though. For most of those we do the check daily then send them off once a year for recalibration, which to me makes no sense since they are still passing the calibration checks.

We also have to send the NIST certified weights off once a year to have them recertified so that we can continue to use them to check balance calibrations before we check the pipettor calibrations.

I am ok with traceability, but I am afraid one day there will be auditors asking for the lot number of the toilet paper used to "maintain" the analysts the perform the tests.