Chromatography Forum

Yeah ... I'm sorry to revive this topic, but despite many topics here, some doubts still remain.

I'm using that method with FMOC-CL, Borate and Citrate buffer, but some FMOC-OH remains in the sample and appears in the chromatogram almost at the same RT of alendronate.

Some people are using glycine to separate those peaks, and here is my doubt. How do they do it? Is there a best other method to do this?

Could somebody help me, please?

Are you mixing your samples with methylene chloride and
using the supernatent?

yep, exactly like the article!

Have you tried increasing the shake time?
Or increasing the amount of methelene chloride?

Shake time, yes, but not increasing the amount of methilene chloride.

Did you separate the methylene chloride by centrifugation? If you just rely on gravity small droplets of MeCl2 could be trapped in the aqueos phase.

Did you separate the methylene chloride by centrifugation? If you just rely on gravity small droplets of MeCl2 could be trapped in the aqueos phase.

No ... I just used gravity to get a phase separation, but it seems a good separation with no visual MeCl2 in the sample.

I didn´t make any tests after last post, but I think I must try to increment MeCl2 like Bryan told me and some centrifugation too.
I will post the results when I get them.

Thanks to all for help!!!