pH Buffer Solutions

[Tobor_8thMan]

Always good to shop around.

http://www.testequipmentdepot.com/m...storage-solution-ph-orp-electrodes-ma9015.htm
https://milwaukeeinstruments.com/milwaukee-ma9015-storage-solution-for-ph-orp-electrodes-230ml/
Milwaukee Instruments posts coupons at HBT. Test Equipment Depot had a nice sale around Thanksgiving. Prices change at both due to supply/demand.

 

[day_trippr]

So I can 'roll my own' storage solution by making a >3 mol mixture of potassium chloride and, what, distilled water? It's as simple as that?[...]

Yup. It's pretty simple. This is from the Denver Instrument Co. Pretty confident you can round to at least 22.4 grams if not 23

A 3M KCl filling solution can be easily prepared using Potassium Chloride in the crystalline form and deionized water. Please follow the steps carefully so you do not change the reference potential of your electrode.

1) Dry the Potassium Chloride carefully in an oven for 2-3 hours
2) Using an analytical balance, carefully weigh 22.368 grams of KCl.
3) Transfer the KCl to a 100 ml class A volumetric flask.
4) Fill the flask to the fill line and mix thoroughly.
5) Verify the volume of the solution after KCl is completely dissolved.
6) Transfer to original filling bottle for use in electrode.

Cheers!

 

[Tobor_8thMan]

I appreciate everyone's input and help. I used my pH meter for the first time when I brewed on December 23, 2020.

I now have a question about the rinse solution. I poured a bit of rinse solution into a beaker and reused it for the whole brewing session. Should I have used new rinse solution each "rinse" instead of reusing the same rinse solution for the whole brew session?

 

[day_trippr]

It would totally suck if that "rinse solution" is just DI water
I rinse the sensor using RO water from the el cheapo RO faucet on my brew sink.
After a good shaking it goes immediately back in its storage solution until the next check (which could be just minutes away - it's become automatic).
Every few brew days it gets a 30 minute soak in cleaning solution, then an RO rinse and back in the storage solution again.

Without knowing what a "rinse solution" actually does I can't say if it makes sense to reuse it or not...

Cheers!

 

[VikeMan]

It would totally suck if that "rinse solution" is just DI water
I rinse the sensor using RO water from the el cheapo RO faucet on my brew sink.
After a good shaking it goes immediately back in its storage solution until the next check (which could be just minutes away - it's become automatic).

Similar here.
Storage -> Distilled Rinse and Blot -> Measurement -> Distilled Rinse and Blot -> Storage

 

[Tobor_8thMan]

What's what I do, test, rinse, storage. What about changing the rinse solution during the brew day?

 

[Tom R]

Lately I have been using my distilled rinse water in one of these. I just squirt it a bit, then gently pat dry.

 

[VikeMan]

^ This. I believe this is a fairly standard lab practice.

 

[Tobor_8thMan]

I bought a few brand new, brown glass medical type bottles with screw on lids. I plan to use the brown glass bottles for storing the buffer solutions (4 pH and 7 pH) in a cold environment to prolong the life of the buffer solutions.

My question. If I wash and rinse the new brown bottles won't I contaminate them for storing the pH buffer solutions? Will this change the pH of the buffer solutions?

Or, should I wash, rinse and allow to completely dry and then there is no worry of changing/contaminating the pH when the buffer solutions are poured into the brown bottles for storage?

Thanks.

 

[VikeMan]

My question. If I wash and rinse the new brown bottles won't I contaminate them for storing the pH buffer solutions? Will this change the pH of the buffer solutions?

I rinse my (brew day) buffer containers with distilled water and let dry.

 

[Tobor_8thMan]

I'm asking more about first washing of the brown bottles. They are new and wrapped in plastic. Just a quick rinse with distilled water?

 

[VikeMan]

I'm asking more about first washing of the brown bottles. They are new and wrapped in plastic. Just a quick rinse with distilled water?

Not knowing how they were made/processed, I would probably wash them with detergent, rinse well, then final rinse with distilled water.

 

[Tobor_8thMan]

OK, thanks. That's easy.