At 11:53 AM 9/29/00 -0400, Ritter, Nadine wrote:
>In addition to having similar serious problems with Agilent sequencing
>reagents over the last several months, we are now experiencing issues with
>their sinnapinic acid for MALDI-TOF. Does anyone have recommendations for
>alternate suppliers of this reagent? Is anyone else experiencing problems
>with this?
>
>Nadine Ritter
>BioReliance
Sinapinic acid goes bad over time. We've been using Aldrich's for about a year. It's been doing well, but we recently noticed that the results for standards weren't quite as good as they had been. A friend recommended washing it with hexane, which cleans it up very well. We take 5mg of SA, vortex it with 400uL of hexane, centrifuge it about a minute, decant the hexane, and repeat. Then we add the usual solvents to get a saturated solution. You can blow off the residual hexane if you want, but it doesn't seem to cause a problem if you leave it. The sample peaks are sharper and more intense than with the unwashed SA, and the spot is more consistent.
If you notice problems with alpha (HCCA, CHCA, or whatever term you use), you can wash it quickly with a little acetone and then make the matrix as usual.
For those of you who aren't aware of it, there is a newsgroup for mass spectrometry, sci.techniques.mass-spec. More information is on our Web page at <http://www.chemistry.gatech.edu/stms/>. You're welcome to participate, and if you'd like to submit articles by e-mail, you can send them to <mass.spec@gatech.edu> as well as to the ABRF list.
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