Hi all!
I am planning to dry some organic samples (calcium carbonate + unkonwn amount of organics ~20mg) in order to remove the water content before gravimetrich analysis.
So I was wondering if there is a standard way of drying in a controlled way small amounts of powder, to 1) remove the water content and 2) don't burn off any organics within the sample.
I was thinking to dry them in a convexion oven at just 45°C fro 48h but I am not sure if it would be ok.
Thank you so much!
Freeze-drying works wonderfully, if you have freeze-dryer on hand. Weigh your sample prior to freezing and transfer the frozen samples with a loose cover (to avoid splattering) to the freeze-dryer. Let dry for 48 hours and re-weigh.
Luca, I have used 60°C for 24h for drying stomach content and it worked good for me: water removed and small copepods were not found burned.
Drying in a convection oven at 20 degrees C would be best. Weigh the samples every 12 hours and continue the drying until weight loss is at an acceptable level. Sixty degrees would probably work, but you need to try different temperatures to determine the best method for your samples. .Air drying is used in Calgary, but the relative humidity is quite low here.
Stuart.
The normal protocol I would use is drying in a convection oven, at 60 degrees C until the samples reach constant weight, So check the samples every 12 - 24 hours and continue drying until there is no longer a change in mass over 2 - 3 intervals. This is the standard method used for dry mass of fauna, algae and sediments
Freeze-drying works wonderfully, if you have freeze-dryer on hand. Weigh your sample prior to freezing and transfer the frozen samples with a loose cover (to avoid splattering) to the freeze-dryer. Let dry for 48 hours and re-weigh.
Cryodesiccation is the better choice. The sediments can be freeze-dried in 2 days or long which is decided by the water content in your samples.
Hi all,
I used the drying oven to dry the river sediment with 105oC in 24h to remove water. After that, the sediment was heated by Furnace at 400oC in 4h to remove organic matter. Then, I use the sediment for heavy metal adsorption. Is it correct?
Thank you very much for all your help.
Kien Nguyen
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