Normally, the procedure for extraction of compounds from food material whether dry or wet are similar. The method for the fresh sample should be applicable to dry sample as well. Just that the dry sample may have higher concentration of the compound per gram sample compare with the fresh sample.

Obafemi Obajemihi Thank you very much for your explanation. The plant materials I used in my experiment are tree species, like jack pine and trembling aspen. These samples were already freeze dried. I will try to use lower gram of my samples to test the proline. Thank you for your help.

@yexin han, my pleasure, I use the same gram for the determination of both dry and wet, specifically 4 g in most cases like ascorbic acids or lycopene determination. Normally, for these bioactives the value after drying could be lower than fresh due to adverse effects of heat and their thermolabile nature but in most cases for some other compounds they may have higher value after drying compared to fresh due to higher concentration like I mentioned before. Either way it is not a problem as those outcomes could be understood. I will suggest you used the same grams for both fresh and dry analysis except you have some peculiarities in your research to cater for.