Alkalinity Standard

[Bryan]

Randy:

Is there a simple recipe (baking soda etc)I could use to create a alkalinity standard to test my various alkalinity test kits.

thanks

 

[Randy Holmes-Farley]

I haven 't worked out a simple standard for that, but I suppose it can be done with baking soda in RO/DI water. Let me check into it.

 

[Bryan]

Thanks Randy. I have access to a scale and a so I can be fairly precise in the weight of the baking soda.

 

[Randy Holmes-Farley]

That's good.

If you dissolve 0.084 grams of baking soda in a liter of RO/DI water (check to make sure its alkalinity is 0), then that should have an alkalinity of 1 meq/L (2.8 dKH).

To get better sensitivity from the balance and the kit, I'd use 4 times that, or 0.34 grams baking soda in 1 L (= 4 meq/L = 11 dKH).

 

[Bryan]

Thanks Randy. Does it matter if the baking soda has absorbed some moisture. Or should I bake it first. Will let you know how it turns out.

 

[Randy Holmes-Farley]

I would get a fresh box and not bake it. Absorbed moisture would be a problem, as would driven out CO2 and water. How much either of those may have happened in advance of your getting it is a limitation on the accuracy of the standard.