Dear Shazia,

I'm pretty sure that ethanol will evaporate during autoclaving pretty vigourously so you'll loose some samples.

Witek

I think this procedure is not appropriate

Dear Shazia , I will strongly  stop such operations , I have few live examples of Explosions of exactly  such combination of materials in the past, pl just advise the concerned  assistant   staff not to go into such operations, they are many times FATAL. Dr Abid Aziz Ajaz 

Thanks to everyone. I want to get better yield of hydrophilic and lipophilic compounds from plantsby using one solvent only. Can anyone guide me

We still dont know your final objective but I will further suggest you is to l carry out the Soxhlet Extractor in a closed distillation system  with aqueous ethanol , this will extract all of the plant hydrophilic as well as the hydrophobic metabolites   from the tissues & will give you the best yield.

Hi,

Autoclave: as every one advised, it is dangerous to  autoclave the solvents.

If your aim of the study is extract the maximum number of active compounds from plant powder, then at autoclave temperature most of the active compounds will  get degrade.

To get the best extractability of Hydrophilic molecules, use 70: 30 alcohol: water mixture at 60 to 70 degree temperature for atleast 5 times, each time 1: 4 or 1:5 volume.

for single solvent system may not yield complete hydrophilic molecules, then in this case you have to use water alone. 

For lipophilic molecules need little more specificity, methanol, Hexane, MDC, Chloroform, acetone, etc can be applied. in general methanol  or hexane preferable. temperature 50 to 60 degree. 

If you can specify the plant powder or desire active you are looking for then experts can explain thoroughly to get the expected results.

If it is research and analytical go for soxhlet extraction.

If  it is purification and separation then use flask and water bath.

All the best

Jayaram

Hi Shazia, you can start with defatting step with hexane solvent accompanied with ultrasonic to improve the yield of lipophilic metabolites. Then, extract the powder with 70% ethanol with sonication. This would help in extracting most of natural metabolitss. Moreover, you should repeat extraction process 2-3 times to ensure maximum extraction.