When adding deionized (DI) water to phosphorous reagent vials the turn blue even in the absence of phosphorous. Is this normal?

Document ID

Document ID TE1065

Published Date

Published Date 27/05/2017
Question
When adding deionized (DI) water to phosphorous reagent vials the turn blue even in the absence of phosphorous. Is this normal?
Summary
Phosphorous vials turn blue
Answer
When running phosphorous, for best results, measure the reagent blank for each new lot of reagent. In method 8190 and 8048 there are procedures for performing a reagent blank to correct for the blue color caused by the reagents mixing together.