Pipette Replacement?

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mbleill

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Hello, I saw a post recently that referenced a device that measured small liquid volumes accurately but can't find it again. What is a device that performed liquid volume capture and measurement for testing purposes? 5ml to 25 Ml.
I do a lot of testing.
 

Rice_Guy

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I use syringes for measuring liquids as 5 or 10 ml. I have two burette but it is easier to syringe measure than set up a stand. Plastic syringes seem to come with a silicone lubricant so expect them to stick and need replacement after a month with 0.2 normal.

At 50 or 100 cc/ ml I usually use a graduated cylinder. There are 50cc syringes but I don’t feel they have accuracy for measuring.

Many repetitive starting sample volumes I actually weigh to 0.01 gm accuracy since it is easier to clean pipette tips than have twenty 25ml sample pipettes. Be aware of density and put a correction in for volume based tests.
 

BarrelMonkey

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Why do you want to replace pipettes? You can get disposable serological pipettes pretty cheaply (less than $1 each). I use them with a pipette pump (I have 10mL and 25mL versions). I think they are sufficiently accurate for most winemaking lab measurements. Although the pipettes are designed to be disposable, you can re-use them may times. It's easier to clean them if you remove the frit in the top: you can do this by using a small screw as a 'corkscrew' to pull it out.
 

mbleill

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Thanks for the replies. Very helpful.
Background: I have had a Venmetrica 300 Pro Kit for 4 years now It came with various pipettes for transferring wine and chemicals when testing. Since then I have replaced the supplied burette with (2) 10 ml burettes. Being an engineer and not a chemist nor having experience in the medical lab areas I was unfamiliar with some of the lab terminology and practices. My main hassle with testing for SO2 is with the 25 ml plastic sampling pipette. I would suck the wine to the desired level in the end of the pipette and then transfer to the titration vessel. The "frit' in the end of the pipette always gets wet or clogged and makes suction difficult if doing multiple tests. Over time the plastic pipette has gotten stained by red wine and hard to read the graduations.
When you mentioned "pipette pump" a lightbulb went off. Thanks! I searched on Amazon and I think that I found what are talking about. That looks like a perfect solution compared to using your mouth to suck liquid into a pipette. I also ordered some 3 ml disposable pipet and some additional 25 ml pipettes and a glass one that should be able to be cleaned easier. The disposable squeeze bulb 3 ml pipettes work fine and quickly for me. The 5 ml pipette for measuring TA has worked fine so far. Now that I know that they are disposable and cheap I will order some more. Here is the Pipette Pump I found on Amazon, Is this the kind that you use?
 
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If I remember correctly the exact amounts of the sample. titrant and reactants within reason isn't critical for what we do. There is a 25 ml mark on the sample vessel which I mark with a sharpie as well as having a 2 ml mark on the acid and reactant transfer pipettes. I just fill the sample to the mark and squeeze to fill to reagents to the 2 ml mark. For me this is accurate enough.
 

BarrelMonkey

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Thanks for the replies. Very helpful.
Background: Here is the Pipette Pump I found on Amazon, Is this the kind that you use?

Yes, that looks like it, I find it much easier than the squeezy bulb kind. (@Rice_Guy, give it a try, you'll never look back!)

I have the 10mL and 25mL versions; I don't have a need for 2mL. Like you, I have a burette for TA and SO2 titrations but I use these for all my reagent pipettting.
 

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