Is the inversion step in the COD method important after the digestion is performed?

Document ID

Document ID TE226

Published Date

Published Date 27/05/2017
Question
Is the inversion step in the COD method important after the digestion is performed?
Summary
Inversion step in the COD method
Answer
The most common step in the COD method for customers to forget is the reagent vial inversion step. After the digestion and before the vial is fully cooled the vial must be inverted several times. This returns any condensation to the reacted sample. Do not invert the vial again immediately before inserting the vial into the instrument. It is necessary to allow time for un-dissolved particles to settle to the bottom and out of the lightpath of the digital instrument.