Dear Friends
In my case, the liquid extract from microwave assisted extraction is freeze dried to remove the water content. after that, Lc-msms is used to identify type of phenolic acid and flavonoid (file attached). Can I use the FTIR to double check the type of phenolic compound inside the dry extract sample? If i'm not mistaken, phenolic range is 3600-3100 cm-1. is it each type of phenolic acid have their own wavelength respectively?
Looks like there are MANY different phenolics in your sample, FTIR will not tell you much, as there is a lot of overlap between the different phenolics: it might work to differentiate pure compounds, and maybe in simple mixtures (say 2 or 3 phenolic compounds, but even there some serious chemiometry will be needed) but not to identify different compounds in a mixture. NMR might be slightly better, but in all cases from such a complex mixture you'll get very limited information. If you really want to know what you have you'll have to purifiy and identify individually the compounds. Definitely LC-MS is the method of choice for the first screening, as you get 2 or 3-D info (even more if MSn) in a single run.