[kobold]

Hi!

I got a double beam spectrophotometer. I am using a method of phosphurus determination using Ammonium Hepta-Molybdate at 880 nm.

My question is simple: is it correct if I fill the reference cubette with distilled water (because it is the solvent I use)?
Or it would be better to use a blank (everything I use to make the samples without the sample) ?

I am kinda leaning to the opinion that it does not matter which I use but I want your opinion!

Thank you all for your attention!

[Hunter2]

The blank should be done with the same matrix. So the best is to make one with  everything in without the phosphate.
But you can compare a measurement with distilled water, how much is difference to Zero.