By dingyuanma on Thursday, December 25, 2003 - 10:02 pm:

I learned that nonporous reversed-phase column with smaller particles(1.5um) have some advantages,such as higher recovery for protein analysis.We have a Mariner ESI-TOF and a common HP1100 HPLC systerm, I don't know if this column can work well in our instrument. I know that TFA may cause some supression,but I don't know if it can destory the instrument equiped needle tip in our ionspray sourse.I would appreciate it very much if someone could give me some advise.

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By Anonymous on Friday, December 26, 2003 - 03:14 am:

In principle no need to use TFA. Use formic, is as good. Works with porous, but do not know on nonporous.

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By dingyuan on Sunday, December 28, 2003 - 08:29 pm:

Thank you for your concern.I think porous is avaliable for peptide analysis rather than protein.Would you please give me more concrete information.

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By MG on Monday, December 29, 2003 - 06:48 am:

I've used TFA in mobile phases periodically at concentrations less than or equal to 0.2% (v/v) with LC/MS. To my knowledge, it never damaged my ion source. However, it will cause ion suppression, and will stay around as background even when you think you have flushed your system adequately.

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By dingyuan on Tuesday, December 30, 2003 - 12:33 am:

Thanks.We have destroy our tip using chloroform as solvent and think halogen may have bad effect.
That prevent me from drawing a rapid decision.

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By MG on Tuesday, December 30, 2003 - 06:06 am:

Is your ESI needle stainless steel? I would be surpised if chloroform caused damage, although you might not get much ionization.

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By dingyuan on Thursday, January 1, 2004 - 02:39 am:

Yeah, a stainless steel tip is destroyed when using chloroform as solvent. I think halogen may cause some problem.

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By Uwe Neue on Thursday, January 1, 2004 - 07:50 pm:

Symmetry C18 columns work very well with peptides and proteins with formic acid as the modifier. They are available in a 10 nm variety for peptides and a 30 nm variety for proteins. Recovery is without difficulty.

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By dingyuan on Friday, January 2, 2004 - 07:06 pm:

Is sysmmetry C18 a waters product? I obtained some information about Vydac, Jupiter, BioBasic, Discovery BIO Wide Pore.I hope someone could kindly give me some advise.

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By Basil on Wednesday, January 7, 2004 - 04:26 am:

Yes dingyuan, Symmetry is a Waters product..

I've been working with a Symmetry C8 for a developing new methods and now I'm going to buy a C-18 for an specific one.

Hope it helps

Basil

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By dingyuan on Saturday, January 10, 2004 - 01:09 am:

I went away some days. I am pleased to recieved your recomments.Thanks.

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By Anonymous on Wednesday, June 9, 2004 - 11:02 am:

no la conozco, necesito mas informacion