Separating formate from methanesulfonate

[IC-man]

I am trying to analyze methane sulfonate ( mesylate ion); however, I discovered the formate ion has the same retention time(exactly).  I have tried to lower the KOH mM to 5 still no separation.   I see with column selection guide the AS 11 HC uses 1 mM.  I thought the AS 19 4um could separate better( this is what I am utilizing).    The fluoride acetate is really good with the 10 mM starting.   I may try to acidify the sample with h2So4 and utilize the huge PKA difference between formic and methanesulfonic acid.   Start out with 1mM for the first 5 minutes.   This is a hard separation.   Can someone help!  Thanks a million. 

[The_Ion_Lady · Accepted solution]

@IC-man , there are ways focus on IC method development. For early eluters such as fluoride, acetate, formate and methanesulfonate, it is better to use IonPac AS15 or AS18 although AS11-HC can also work. IonPac AS19 format columns are better for late eluters such as phosphate, perchlorate, iodate etc., not really for separation of early eluters.

Virtual column is a good starting point: https://appslab.thermofisher.com/VirtualColumnOnline

Other tips I have is that column temperature can sometimes change the retention times of your analyte.

Here are some method development tips: 5 tips to develop & improve your IC Method.

Watch out for the 2023 Global IC Symposium, coming soon!

I hope that helps you.👍

[IC-man]

Analytical instrumentation:

ICS6000

AS19 4um  (4mm)

DRS600 suppressor 

25uL loop

10mM 0-10min  KOH

10-45mM 10-45min KOH

1.0mL/min

conductivity

[The_Ion_Lady · Accepted solution]

@IC-man , there are ways focus on IC method development. For early eluters such as fluoride, acetate, formate and methanesulfonate, it is better to use IonPac AS15 or AS18 although AS11-HC can also work. IonPac AS19 format columns are better for late eluters such as phosphate, perchlorate, iodate etc., not really for separation of early eluters.

Virtual column is a good starting point: https://appslab.thermofisher.com/VirtualColumnOnline

Other tips I have is that column temperature can sometimes change the retention times of your analyte.

Here are some method development tips: 5 tips to develop & improve your IC Method.

Watch out for the 2023 Global IC Symposium, coming soon!

I hope that helps you.👍

[IC-man · Accepted solution]

Thanks for the help!!!!!!!!!!!  This resolved the  issue  I ordered a AS18.