I tested 1 or 2 drops of diluted acidic Lugol's iodine (1 drop in 10 ml seawater) and 0.5 % formalin solution on 500 ul of Akashiwo sanguinea on slides. The cells sometime fixed, sometime not. Cell also burst frequently after staining.
So I'm trying to prepare a basic version of Lugol's iodine using sodium acetate CH3COONa. However, my lab does not has the anhydrous version but only CH3COONa.3H2O.
I attempted to dry it using oven at 80' c for 1 hour, however, the drying was incomplete, powder still appear moist and tend to stick together. I extended the drying time for another 12 hours at the same temperature.
Do you think this will completely remove the water (.3H2O) from it?
Plus, as part of the preparation work, I weighted KI and Iodine resublimed on Aluminum foil. Of course, a small portion of I2 reacted with the Al foil and change to liquid. I transferred the remaining solid to a crucible and placed it in a desiccator. Do you think I can still re-use the I2 later?
Thanks.
Dear Chee Ping Tan,
There are two methods to convert sodium acetate trihydrate to anhydrous sodium acetate:
1-By melting; the melting point of sodium acetate trihydrate is about 122 C and that of the anhydrous 324 C. Therefore, heating the sodium acetate trihydrate between 122 -324 C results in the evaporation of the water contained in the trihydrate. The resulting powder should be kept in a desiccator having drying agent.
2-By drying under CaCl2; place sodium acetate trihydrate in a desiccator having CaCl2 for 48 hours.
Other drying agents can be used such as Molecular sieve, anhydrous sodium or magnesium sulfate.
Regarding the I2, you can still use it as it.
Hoping this will be helpful,
Rafik
Thank you for your answers. Will proceed as you suggested.
One more question, is it possible in the future to use "hydrated chemical" as "anhydrous form" by simply using a higher amount of hydrated chemical till it equal to that concentration of its anhydrous form?
Dear Chee,
The answer is yes if the drying procedure is conducted as described in my first answer.
Good luck,
Rafik
Yes, I made the solution. The cell A. sanguinea can finally be fixed with a much lower cell distortion. However, for others, do take care to largely dilute the Lugol's iodine before use, cell will still lyse if too much is used.
Thanks Mr. Karaman.
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