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Chemistry Forums for Students => Analytical Chemistry Forum => Topic started by: kobold on March 23, 2023, 11:16:51 AM

Title: Reference Cubette
Post by: kobold on March 23, 2023, 11:16:51 AM

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!

Title: Re: Reference Cubette
Post by: Hunter2 on March 23, 2023, 12:25:46 PM

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.