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Use of formic in negative adquisition mode

Use of formic in negative adquisition mode - Mass Spectrometry Forum

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Old 01-10-2012, 02:13 PM
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Default Use of formic in negative adquisition mode



Hello. I can see some publications in which carboxylic acids (particularly bile acids and methylmalonic and succinic acids) are analyzed by HPLC/MS/MS in negative mode and 0.1% formic acid is added to the mobile phase.
However, formic acid could protonate other carboxylic acids and neutralize the negative charge needed in the negative acquisition mode, isn't it?
As well as in positive mode, why can formic acid be used in negative mode, too?
Thanks.
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Old 03-16-2012, 03:01 AM
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Default Re: Use of formic in negative adquisition mode

Hi.
Just would like to share with you (from a journal), the usage of 0.1% Formic Acid in Positive Mode will Enhance the Ionization. However if we use 0.1% Formic Acid in Negative Mode, it will suppress the Ionization.
It is recommended (in a journal) to use 0.1% ammonia if Negative Mode.
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Old 03-27-2012, 12:44 PM
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Default Re: Use of formic in negative adquisition mode

Thank you very much for your recommendations
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