Does Hach have information as to why the recommended storage is 7 days on Fluoride colorimetric methods 8029 & 10225?

Document ID

Document ID TE352

Published Date

Published Date 25/01/2018
Question
Does Hach have information as to why the recommended storage is 7 days on Fluoride colorimetric methods 8029 & 10225?
Summary
Fluoride sample holding times
Answer
Previous versions of these methods listed storage conditions of 'at least 7 days' in the 'Sample collection and storage' section of the method. Current versions of the methods have been amended to state that samples can be kept for up to 28 days. Currently, the EPA approves the 28 day holding time; however you should always check with your regulator if there are any questions.

Current method versions can be found at www.hach.com/wah