I ran a non-trageted HPLC, because I have no standards to compare with. Can I know the compounds in a certain retention time and wavelength? How?
Depending on the conditions of separation you can say something about the polarity of the compound and something on the basis of its UV spectra. That's all :)
Regards
G
Not really! Many classes of chemicals may have the same UV maximum (PDA/DAD scan), but the chromatographic retention time will be different for each compound. In addition, the detector response for each compound will be different so without the 'pure' (>99%) reference standard you can't say anything.
If you don't have first information about the sample there is no way you can identify the analyte in question without reference. Library data base May help to some degree. No reference no qualitative analysis in HPLC. Retention time will not suffice the need. LC-MS hyphenated technique will certainly help.
How will I be able to analyze my data ? Shall I compare peaks of same retention time?
You wasted your time! If you have an MS/MS detector you might be able to use 'collision induced daughters' (CID) for an identification. But this won't allow quantification since there is NO information on the detector response.
You will have to have an organic chemist make a ~99% pure reference standard for quantification About 500 mg will do.
Dear Aya, Multiple compound can have same retention time and UV spectra. Therefore, I suggest that if you are getting a single good peak, then subject it to mass by direct infusion. Alternatively, if you are getting multiple peak, then you should collect the peak coming out of the detector end concentrate it and subject to mass. Your last option is to subject sample for LCMS.
- Badges
- Science method