By Carlo on Tuesday, November 12, 2002 - 06:30 am:
Dear Friends;
I am having problems with the tailing of peaks relatives to Acetylsalicylic Acid.
I use the method of the USP-24. Do you know other method more efficient for this product?
Tank you.
By Gerhard Kratz on Wednesday, November 13, 2002 - 08:03 am:
Dear Carlo, what kind of RP-column are you using. With a high purity silica based RP-column you should not have such problems. Which column is recommended in the USP-24 method? And what matrix do you have? Please specify. Gerhard
By dm on Wednesday, November 13, 2002 - 05:48 pm:
I agree, any newer, high purity silica-based RP column should provide excellent peak shapes for this suite of compounds. If you are using some older silica (e.g., Hypersil) you'll see tailing for salicylate and related compounds.
Try Waters Symmetry or SymmetryShield, Keystone BetaBasic8, etc.
By Carlo on Thursday, November 14, 2002 - 05:42 am:
Dear Friends,
Tank yoy for your helps.
I am using a Hypersil Column c-18, and the peaks are assymetric (peaks relatives to Acetylsalycilic and Salycilic Acids), and I do not want it.
Do you have poor assymmetries with your columns?
By Anonymous on Thursday, November 14, 2002 - 08:56 am:
I'm using an X-Terra RP18 15 cm 3.9 mm, no problemo. Very symetric peaks
By Carlo on Thursday, November 14, 2002 - 11:51 am:
Hi Anonymous 08:56,
Do you invite a copy of your chromatogram with symetric peak relative to Acetylsalicic Acid?
Tanks
By Carlo on Thursday, November 14, 2002 - 11:52 am:
Hi Anonnymous 08:56;
Maybe you invite-me a coy of your chromatogram with symetric peak relative to Acetylsalycilic Acid?
Tanks
By deST on Thursday, November 14, 2002 - 11:56 am:
Hi Carlo;
Use a C-8 column to improve your symmetry.
By Anonymous on Friday, November 15, 2002 - 08:05 am:
Hi Carlo,
please put a message here with your e-mail adress, so I can send it to you with e-mail.
By Carlo on Monday, November 18, 2002 - 06:40 am:
Sorry Anom 0805,
Send your chromatogram to teixeiracs@yahoo.com
Tank you
By Anonymous on Monday, November 18, 2002 - 05:55 pm:
A C8 column will not improve peak symmetry. Salicylate (and acetyl salicylate) will tail horribly on Hypersil. I spent a year developing this method and Hypersil ODS was far and away the worst column for tailing.
A newer, higher purity silica column will work wonderfully for these compounds. Save yourself the aggrevation and put the Hypersil column in the drawer.