When using UniVer® 3 and the sample has copper and iron concerns, are there additional steps that can be attempted to minimize interference?

Document ID

Document ID TE294

Version

Version 2.0

Status

Status Published

Published Date

Published Date 27/05/2017
Question
When using UniVer® 3 and the sample has copper and iron concerns, are there additional steps that can be attempted to minimize interference?
Summary
Steps to minimize copper and iron interference when using UniVer® 3
Answer
In kits containing UniVer® 3, copper is an interference which some customers might run into. Make sure to add 3 drops of titrant when using 100 mls of sample, or 1 drop of titrant when using 5.83 mls of sample, before beginning the test. This should result in a slow endpoint when copper is present.
If the sample has iron interference when using UniVer® 3, try titrating very quickly after adding the indicator, or add two UniVer® 3 powder pillows and then titrate fast. The iron destroys the indicator. Additionally, try adding a drop or two of the titrant before adding the UniVer and then titrate, count the pre-drops into the final results.