[RASMB] Aluminum SV Cell Corrosion

Fri Nov 16 14:39:26 PST 2007

James, we have a centerpiece chemical compatibility table on the web:

http://uslims.uthscsa.edu/cauma/cell.php

It shows unsatisfactory resistance of anodized aluminum against NaCl.
Since you have a high concentration of it, you would be better off not
to use it in alu centerpieces, especially not for extended times.

You could use either titanium centerpieces (60 krpm, inert) available
from Kristian Schilling at Nanolytics (nanolytics.de), or you could
run the epon centerpieces (even up to 60 krpm as long as you don't
have any leaks in either channel and keep the two channels closely 
balanced to avoid differential hydrostatic pressure, BUT: THIS VOIDS
BECKMAN WARRANTY!). If you are unsure, check your buffer first on a 
cheap plate of anodized aluminum before ruining an expensive centerpiece.
I don't know how to fix corroded centerpieces, maybe Tom Laue can comment
on this.

Regards, -Borries

> 
> Dear Colleagues,
> 
> Recently, I used aluminum centerpieces for the first time and found  
> what appears to be corrosion on both the centerpiece as well as the  
> cell housing.  The cell was allowed to sit for about 1 week after the  
> run was complete before cleaning.  I did not notice substantial  
> leaking (the sample and reference channels were not noticeably  
> depleted), but clearly some leaking must have taken place.  My buffer  
> is 10 mM phosphate, 200 mM NaCl, pH 7.2.
> If anyone has any advice regarding 1) cleaning off the corrosion, 2)  
> whether this cell is still usable, or 3) how to prevent this in the  
> future, I would appreciate it.
> 
> Thank you,
> James
> 
> ------------------------------------------------------------------------ 
> -------------------
> E. James Petersson                     email: e.james.petersson at yale.edu
> Department of Chemistry            Lab:   203-432-8940
> Yale University                             Cell:  626-644-1091
> 225 Prospect St.                           Fax:   203-432-3486
> New Haven, CT 06511
> 
> 
> 
> 
> --Apple-Mail-1-36824926
> Content-Transfer-Encoding: quoted-printable
> Content-Type: text/html;
> 	charset=ISO-8859-1
> 
> <HTML><BODY style=3D"word-wrap: break-word; -khtml-nbsp-mode: space; =
> -khtml-line-break: after-white-space; ">Dear Colleagues,<DIV><BR =
> class=3D"khtml-block-placeholder"></DIV><DIV>Recently, I used aluminum =
> centerpieces for the first time and found what appears to be corrosion =
> on both the centerpiece as well as the cell housing.=A0 The cell was =
> allowed to sit for about 1 week after the run was complete before =
> cleaning.=A0 I did not notice substantial leaking (the sample and =
> reference channels were not noticeably depleted), but clearly some =
> leaking must have taken place.=A0 My buffer is 10 mM phosphate, 200 mM =
> NaCl, pH 7.2.</DIV><DIV>If anyone has any advice regarding 1) cleaning =
> off the corrosion, 2) whether this cell is still usable, or 3) how to =
> prevent this in the future, I would appreciate it.</DIV><DIV><BR =
> class=3D"khtml-block-placeholder"></DIV><DIV>Thank =
> you,</DIV><DIV>James</DIV><DIV><BR><DIV> <SPAN class=3D"Apple-style-span" =
> style=3D"border-collapse: separate; border-spacing: 0px 0px; color: =
> rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: =
> normal; font-variant: normal; font-weight: normal; letter-spacing: =
> normal; line-height: normal; text-align: auto; =
> -khtml-text-decorations-in-effect: none; text-indent: 0px; =
> -apple-text-size-adjust: auto; text-transform: none; orphans: 2; =
> white-space: normal; widows: 2; word-spacing: 0px; "><DIV =
> style=3D"margin-top: 0px; margin-right: 0px; margin-bottom: 0px; =
> margin-left: 0px; =
> ">------------------------------------------------------------------------=
> -------------------</DIV><DIV style=3D"margin-top: 0px; margin-right: =
> 0px; margin-bottom: 0px; margin-left: 0px; ">E. James Petersson=A0 =A0=A0 =
> =A0=A0 =A0=A0 =A0=A0 =A0=A0 =A0=A0 =A0email:<SPAN =
> class=3D"Apple-converted-space">=A0</SPAN><A =
> href=3D"mailto:e.james.petersson at yale.edu"><FONT =
> class=3D"Apple-style-span" color=3D"#0020DE"><SPAN =
> class=3D"Apple-style-span" style=3D"color: rgb(0, 32, 222); =
> -khtml-text-decorations-in-effect: underline; =
> ">e.james.petersson at yale.edu</SPAN></FONT></A></DIV><DIV =
> style=3D"margin-top: 0px; margin-right: 0px; margin-bottom: 0px; =
> margin-left: 0px; ">Department of Chemistry=A0 =A0 =A0 =A0 =A0 =A0 =
> Lab:=A0=A0 203-432-8940</DIV><DIV style=3D"margin-top: 0px; =
> margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">Yale =
> University=A0 =A0 =A0=A0 =A0=A0 =A0=A0 =A0=A0 =A0=A0 =A0=A0 =A0=A0 =A0=A0 =
> =A0Cell:=A0 626-644-1091</DIV><DIV style=3D"margin-top: 0px; =
> margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">225 Prospect =
> St.=A0 =A0=A0 =A0=A0 =A0=A0 =A0=A0 =A0=A0 =A0=A0 =A0=A0 =A0=A0 =A0Fax:=A0=A0=
>  203-432-3486</DIV><DIV style=3D"margin-top: 0px; margin-right: 0px; =
> margin-bottom: 0px; margin-left: 0px; ">New Haven, CT 06511</DIV><DIV =
> style=3D"margin-top: 0px; margin-right: 0px; margin-bottom: 0px; =
> margin-left: 0px; "><BR class=3D"khtml-block-placeholder"></DIV><BR =
> class=3D"Apple-interchange-newline"></SPAN> =
> </DIV><BR></DIV></BODY></HTML>=
> 
> --Apple-Mail-1-36824926--
> 
> --===============1283623639==
> Content-Type: text/plain; charset="us-ascii"
> MIME-Version: 1.0
> Content-Transfer-Encoding: 7bit
> Content-Disposition: inline
> 
> _______________________________________________
> RASMB mailing list
> RASMB at rasmb.bbri.org
> http://rasmb.bbri.org/mailman/listinfo/rasmb
> 
> --===============1283623639==--
> 