I've had that problem. We switched to biorad capless 1.5ml micro tubes cat# 223-9500 and the problem disappeared.
Amina
On Wednesday, February 03, 1999 8:21 PM, Ken Mitchelhill [SMTP:k.mitchelhill@medicine.unimelb.edu.au] wrote:
> Colleagues,
>
> we have had discussions in the past regarding leeching of "detergent like"
> polymers from tubes that swamp ESI spectra.
>
> I thought I was using relatively MS clean tubes until recently when I have
> been undertaking an exhaustive study of a protein digest by nano-ESI MS/MS
> where I have had, because of the size of the project, to store fractions
> for a few weeks at -20 degrees C.
>
> I have noticed that fractions containing more than about 25% acetonitrile
> contain these pesky polymers after about a weeks storage. The polymers are
> not present in the original solvent and their time dependent appearance
> seems also to be organic concentration dependent.
>
> Apart from the obvious solutions like doing the experiment quicker or
> removing the organic solvent by evaporation prior to storage, does anyone
> out there have other suggestions.
>
> In particular, is anyone using a tube (specific make and model required
> here) where one can store say 60% acetonitrile for weeks without extracting
> polymeric material from the plastic?
>
> Regards....Ken
>
> ********************************
>
> Ken I. Mitchelhill
> The John Holt Protein Structure Laboratory
> St. Vincent's Institute of Medical Research
> 41 Victoria Parade
> Fitzroy 3065 Victoria
> AUSTRALIA
>
> Telephone: 61-3-9288 2480
> Facsimile: 61-3-9416 2676
>
> Email: k.mitchelhill@medicine.unimelb.edu.au
>
> Laboratory: http://www.medstv.unimelb.edu.au/WWWDOCS/SVIMRdocs/JHPSL.html
> ABRF: http://www.abrf.org
>
> ***********************************
>