Dear All
I'm planning to use HPLC-MS in identification of type phenolic compound in my sample solution extraction. I will extract dragon fruit peel into Microwave Assisted Extraction (MAE) by using pure water as a solvent. Should I use Rotary evaporator to remove water content inside the solution extraction? I'm worried the high temperature during evaporation will degrade some of the phenolic compound. Can I just centrifuge the solution extraction to get the supernatant and directly read at hplc-ms without purification process (rotary evaporator) ?
What temperature will you reach during the microwave assisted extraction? It it is high, the rotary evaporation won't be any worse at decomposing product.
You can try freeze-drying the sample too.
Dear Dr Jack Silver
the temperature applied at Microwave Assisted Extraction is 45 °C. I believe that to remove water content (as solvent) from the solution extraction will apply 100°C at rotary evaporator (might be damage certain type of phenolic compound). if i apply freeze dryer to remove water content, for sure my solution extraction will freeze, so i need to dissolve using another solvent (e.g: ethanol/water) at my sample once again before analyzed via hplc-ms..Am I right?
Dear olga
I used freeze dryer before extraction process. it takes 4 days to completely dry my sample which is dragon fruit peel. i believe it will keep integrity of active compound in my sample. but never try apply freeze drying technique to remove solvent from solution extraction. If you have any journal/information related on this question. Let's share with us
Hi Azlan,
As for my preliminary work before, normally I use 60C (water) for rotavap ( will take hours to concentrate) and for analysis before HPLC you can dissolve in MeOH
Dear Azlan,
A number of polyphenols have previously been shown to degrade at approx 60 or higher, therefore it is best to avoid prolonged periods of heating.
If you have access to a freeze dryer I would recommend using this technique to fully dry your sample. Once you have done this resuspend your sample in methanol to get a known concentration e.g. 1 mg/ml. As this is a water extract some of the extracted material (e.g. carbohydrates) may not dissolve in the methanol. As such, be sure to either filter (PVDF filter) or centrifuge your sample before running on LCMS system.
Dear Owen
Thanks for your answer. yes this is the water extract. May i know is carbohydrate linked/attached with the phenolic compound? as i'm not detect carbohydrate compound in this study. Do you have any journal that related with degradation of phenolic compound and freeze drying technique to fully dry our sample? if you have, just share with me. thanks
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