Chromatography Forum

Is it possible/advised? If yes can someone guide me? I have access to an only C18 column. LC coupled QTOF. I tried with the following method.

Sample extraction: diluted diesel sample with acetone. and diluted further with 75:25 acetonitrile:water. Buffer A=75:25 acetonitrile:water and buffer B=acetone. Gradient program from 100% A to 100% B in 30 minutes. But I am not getting sharp peaks.

I am aware that I should not expect hydrocarbons since it is an ESI source. Is there any derivatization methods to detect them?

What are your target analytes?
Why derivatize hydrocarbons? That is what GC/FID is made for.

Hi Steve. Thanks for your response. My goal is to create fatty acids profile in biodiesel. I know it’s much easier in GCMS or GCFID. However, I wanted to know if it’s possible in LCMS.

Let’s say, if I don’t have access to GC. In that case, can I use LCMS with some kind of derivatization for hydrocarbons?

However, my main query is sample preparation for fatty acids profiling.

Hi arnabroy,

what do you want to do? Analyse Diesel with LCMS - impossible. Analyse BIODIESEL with LCMS - that's possible. In Biodiesel you don't have hydrocarbons, you have FAMEs.

Hi Thomas, Thanks for your input. Yes, I am trying to detect FAMEs in biodiesel. Can you please let me know a good sample preparation for this? I am also interested to detect fatty acids in milk scum.