Hanna reagent mixing. Ok or Avoid

[Tangdora]

Hi all.

Few of the Hanna reagent come in liquid form. I’m curious is there is any risk to result accuracy by mixing the liquid bottle say when it get down to 10% and you restock in order to be able to toss the old bottle. Now I’m not talking about mixing something that like month or two out from expiration. For example I just picked new ammonia. The old bottle has about 10% left and the expiration shows 2028. The new bottle shows 2029. Even if I mixed the solution I would will be used up long before then.

Thanks.

 

[Ryan Souza]

I can only speak for the alk reagent since that's the only liquid I use, however I would not mix it as I notice the last bit of alk reagent 10 or 15% is ALWAYS off versus a fresh batch. I've seen it off by .2 to .4 dkh, which I'm not good with so I chuck it. And these are years out from expiration.

 

[Randy Holmes-Farley Verified Community Expert]

In theory, there is no issue, but as noted, if the reagent is going bad, it may skew the results of the new reagent.

 

[Dan_P]

Hi all.

Few of the Hanna reagent come in liquid form. I’m curious is there is any risk to result accuracy by mixing the liquid bottle say when it get down to 10% and you restock in order to be able to toss the old bottle. Now I’m not talking about mixing something that like month or two out from expiration. For example I just picked new ammonia. The old bottle has about 10% left and the expiration shows 2028. The new bottle shows 2029. Even if I mixed the solution I would will be used up long before then.

Thanks.

Depends on the reagent. The risk of a bad effect is not the same for all reagents. Avoid mixing titration reagents.

Which reagents are you interested in mixing?

 

[KrisReef]

Reagent is supposed to be reactive to provide results in a test situation. Old reagents can give false results if they are old and partially reacted from aging in the bottle (Oxidation to environmental contamination.)

Trying to be thrifty can ruin the results that you want from the test just to save a bottle of old reagents that have lost their integrity.

If you found a bottle of champagne that was opened a week ago in the back of the fridge would you open up a new bottle and mix it with the old to make it fizzy again before you serve it to your girlfriend?

I guess it could depend on how much you like her and how much you value her opinion and friendship?

Test results have consequences, so do your best.

 

[exnisstech]

I've done this with Hanna alk reagent for years and haven't noticed any problems. I don't use expired reagent and I always test my new bottles when I open them just to compare it to the current bottle in use.

 

[Dan_P]

If you found a bottle of champagne that was opened a week ago in the back of the fridge would you open up a new bottle and mix it with the old to make it fizzy again before you serve it to your girlfriend?

Ans: Drink the old one myself, share the fizzy one

 

[KrisReef]

Ans: Drink the old one myself, share the fizzy one

This speaks well of your girlfriend!