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

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.