****************************************************************************** From: Yining Zhao Date: Sun, 17 Jan 1999 14:20:39 +0100 (MET) Subject: polysulfatedsaccharides Organization: * Hi, Gentlemen: I'm tryin to get good sensitivity of a polysulfated polysaccharide sodium salt (MW 1726)in negative ESI mode. However, it barely gave the multiple-charged signals due to its very strong sodium affinity. I've used high content of TEA, Imidazole etc. such basic addutives in my makeup liquid, but the spectrum is still unsatisfied. Will you give me your experiences with such sort of compounds ? thanks in advance ----------------------------------- ****************************************************************************** From: William Cotham Date: Tue, 19 Jan 1999 13:20:02 -0500 Subject: Re: polysulfatedsaccharides Organization: Univ. of South Carolina, Columbia A molecule that small will probably not want to hold multiple charges. I would expect the singly charged anion to be most abundant. -- William E. Cotham, Ph.D. Mass Spectrometry Laboratory Dept. of Chemistry & Biochemistry University of South Carolina Columbia, SC 29208 Phone: (803) 777-2039 FAX : (803) 777-9521 ****************************************************************************** From: Peter Jacobs +31 412 661688 Date: Wed, 20 Jan 1999 10:00:01 +0000 (GMT) Subject: RE: polysulfated saccharides Organization: * With ESI a Dionex suppressor might help (or Dowex desalting); with MALDI the addition of basic (RG)n peptides as described originally by Peter Juhasz. ASMS abstracts on these subjects: Palm Springs, 1997 p1033 (MALDI) Portland, 1996 p565 (Ionspray) For an overview of ms approaches read the article below and references therein: Application of mass spectrometry to the analysis of natural and synthetic sulfated oligosaccharides glycosaminoglycans L. Silvestro, S. Rizea Savu, P.A. van Veelen and P.L. Jacobs - In: "Non-anticoagulant Actions of Glycosaminoglycans" Ed. Prof. J. Harenberg and B. Casu, eds., Plenum Press, New York, 1996 ISBN 0-306-45299-5 Peter Jacobs E-mail: p.jacobs@organon.oss.akzonobel.nl ****************************************************************************** From: Thomas Storm Date: Wed, 20 Jan 1999 09:36:30 +0100 Subject: Re: polysulfated saccharides Organization: TU-Berlin Hello, try removing sodium by a strong cation exchanger if your analyte survives a acidic environment. Did work with a polysulfonated polymer samples I once measured in negative ESI. Best Thomas -- Thomas Storm TU-Berlin Fachgebiet Wasserreinhaltung Sekr. KF4 Strasse des 17.Juni 135 10623 Berlin Tel. ++49 (0) 30 314 25480 FAX ++49 (0) 30 314 23850 e-mail: storm@itu203.ut.tu-berlin.de ****************************************************************************** From: cody@jeol.com (Chip Cody) Subject: Re: polysulfatedsaccharides Date: Wed, 20 Jan 1999 20:41:37 GMT Organization: JEOL USA, Inc. In my experience, multiple charges are often observed for molecules in this molecular weight range. However, the degree of charging can be concentration-dependent as well as solvent-dependent. You might try a more a more dilute solution, and beware of salty solvents and glass containers. HPLC-grade purity is not a good guarantee that water is sodium-free (HPLC-grade often is only an indication that UV absorbers areabsent). Use a good quality water purification system if you have not already done so. No doubt other readers of this newsgroup will have additional suggestions to offer. Good luck! -- "For purposes of ... New Jersey Right to Know Act. Contents partially unknown." |____________ |_ Robert B. Cody, Ph.D |________________________________ Product Development Manager |__ Mass Spectrometry |________________________ JEOL USA, Inc. |_ http://www.jeol.com |__________ e-mail: cody@nojunkmail.jeol.com |_ (REMOVE 'nojunkmail' TO REPLY) ============== Do not send me spam or advertising via e-mail !! =========