By Anonymous on Tuesday, April 13, 2004 - 12:13 pm:

Hi

I just want to know if anyone knows a HPLC method to separate and quantify preservatives in cosmetics (sorbic acid, benzoic acid, phenoxethanol and methyl-ethyl-propyl-butyl-isobutylparaben) if possible an isocratic condition?

Thank you for your answer

David

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By Durk on Tuesday, April 13, 2004 - 11:20 pm:

Hi David,

We have a method for the components you mention. We described the method in Dutch, but the most important parameters will be no problem I think. I can mail you this method. Please let me know.

Durk

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By David Vilbert on Tuesday, April 13, 2004 - 11:39 pm:

Dear Durk

I really would appreciate your method even in Deutch !!!
You can send it to david.vilbert@orange.fr

Have a nice day

David

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By carmen on Tuesday, June 8, 2004 - 09:55 am:

Friends, I need your help.
I need detect benzoic acid and sorbic by HPLC, and I use, MeOH/phosphate buffer pH=7, 10/90. The column is C-18, and UV-230 nm. My problem is that I have two peaks not very good separeted at 4 minuts, (1 mL/min). I don't know wich peak is good.
Please, help

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By Durk on Wednesday, June 9, 2004 - 01:22 am:

Carmen,

Try Acetonitrile/acetate buffer pH 4.5 (20/80). Prepare the acetate buffer by 2.3 gram sodiumacetate per litre. Benzoic acid will migrate at 4.5 minutes and sorbic acid at 6.5 minutes with a flow of 1 ml/min at a C18 column.

Durk