Sodium lauryl sulfate damage a CN column? [August 10, 2004]
Posted: Sun Aug 29, 2004 6:36 pm
By dcobice on Tuesday, August 10, 2004 - 05:35 am:
Hello! Can anyone please tell me if sodium lauryl sulfate is bound to damage a CN column? This salt is present in my sample and 20 ul of a 1% m/V solution are injected per run. Thanks a lot.
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By popeye on Wednesday, August 18, 2004 - 04:59 am:
Sodium Lauryl Sulphate IS bound to damage any column. Flush your column properly with water and then ACN.
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By Mary on Wednesday, August 18, 2004 - 09:17 am:
Why is it bound to damage any column and what are the signs of damage? Thank you.
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By tom jupille on Wednesday, August 18, 2004 - 04:01 pm:
I don't know that SLS is *bound* to damage a column, but the potential is certainly there because it is very strongly retained and so will build up on the head of the column. Since it's ionic, that means that negative charge will build on the column. SLS can be very difficult to remove from a column (even with thorough rinsing), so there is the risk of irreversible change to the column chemistry.
Symptoms are shifts in retention, especially if bases shift to longer retention relative to neutrals. The catch is that the effect on the separation can range from negligible to catastrophic.
So: if you're not seeing retention or selectivity shifts, don't worry about it (but, by the same token, don't use that column for any other method!). If you *are* seeing shifts in retention or selectivity, try washing the column as suggested by popeye. If you can't get the original selectivity back, the column is indeed dead. For the future, you can either change the sample workup to get rid of the SLS before you get to the HPLC or else use a guard cartridge to trap the SLS before your analytical column (and remember to change the guard cartridge now and then!).
Hello! Can anyone please tell me if sodium lauryl sulfate is bound to damage a CN column? This salt is present in my sample and 20 ul of a 1% m/V solution are injected per run. Thanks a lot.
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By popeye on Wednesday, August 18, 2004 - 04:59 am:
Sodium Lauryl Sulphate IS bound to damage any column. Flush your column properly with water and then ACN.
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By Mary on Wednesday, August 18, 2004 - 09:17 am:
Why is it bound to damage any column and what are the signs of damage? Thank you.
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By tom jupille on Wednesday, August 18, 2004 - 04:01 pm:
I don't know that SLS is *bound* to damage a column, but the potential is certainly there because it is very strongly retained and so will build up on the head of the column. Since it's ionic, that means that negative charge will build on the column. SLS can be very difficult to remove from a column (even with thorough rinsing), so there is the risk of irreversible change to the column chemistry.
Symptoms are shifts in retention, especially if bases shift to longer retention relative to neutrals. The catch is that the effect on the separation can range from negligible to catastrophic.
So: if you're not seeing retention or selectivity shifts, don't worry about it (but, by the same token, don't use that column for any other method!). If you *are* seeing shifts in retention or selectivity, try washing the column as suggested by popeye. If you can't get the original selectivity back, the column is indeed dead. For the future, you can either change the sample workup to get rid of the SLS before you get to the HPLC or else use a guard cartridge to trap the SLS before your analytical column (and remember to change the guard cartridge now and then!).