Does the Hach DPD chemistry contain both the phosphate buffer and the DPD salt as detailed in Standard Methods?

Document ID

Document ID TE218

Published Date

Published Date 27/05/2017
Question
Does the Hach DPD chemistry contain both the phosphate buffer and the DPD salt as detailed in Standard Methods?
Summary
Composition of DPD Chlorine Reagents
Answer
The Hach DPD formulation will meet this Standard Methods requirement though the formulary is proprietary.  Potassium Iodide is also added to the Total Chlorine DPD chemistry.