Chromatography Forum

how can I know which componenent for which peak?

Figuring this out depends on what you are doing. If you are trying to pick out the peaks in a standard mixture, the easiest is to look for a chromatogram of the mixture on the same stationary phase. Vendors will often provide them. If you do not have a chromatogram on your column, the next step is to look for a table of compounds showing relative retententin times or retention order. These are available various places, depending on whant mixtures you are using.

If you do not have access to such informaition for your mixture, another option is to make solutions of components, and inject them. looking for the peaks generated by each component.

This is assuming you are trying to locate peaks in a standard mixture. If you are trying to locate a peak for ana analyte in a sample, you need to take additional steps to confirm that you do not have some other compound coeluting. This may requie runnign the sample on two different stationary phases or other techniques.

nasss,

This may sound trivial, but if using an FID and looking at fairly large amounts, you can also sort by comparing concentration to peak height. Not the best way, but it does help. If looking for trace levels or using another detector, this idea will quickly fall apart since reactivity or differences in sensitivity will shoot you in the foot.

Best regards,

AICMM