Hi Raùl,

If you do not want to (or cannot) use HPLC, I would suggest HPTLC. It is a simple technique with which you can detect and quantify. You can reveal the plates by U.V. for your benzimidazoles compounds.With proper separation conditions, you can use commercial compounds to identify your compounds within the HPTLC plat by co-elution. If this is not sufficient for identifying your compounds, a simple HRMS after purification with a preparative plate for TLC would be more convincing, with may be additional fragmentation patterns.

Here are two papers where HPTLC is used for benzimidazoles:

- http://www.ijpsonline.com/article.asp?issn=0250-474X;year=2007;volume=69;issue=2;spage=202;epage=205;aulast=Shah

- http://chromsci.oxfordjournals.org/content/46/4/304.short

Hope this could help, cheers,

Nicolas.