I am making a stock solution of Tween 80 (0.05 % w/v) and each experiment requires just 15 ml of the stock solution. Is it possible to make a large batch (about 100 ml) and store it somewhere? If so, what should I look out for when storage?

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    $\begingroup$ Please note that nonconforming units such as "% w/v" should not be used in science and technology. $\endgroup$
    – Loong
    Aug 16 at 17:16

1 Answer 1


The Sigma Aldrich/Merck product information for "TWEEN® 80 solution" states the following:


Aqueous solutions of polysorbates as well as the neat liquid will undergo autoxidation over time, with changes being catalyzed by light, increased temperature, and copper sulfate.[9]

Solutions are reasonably stable at 2 - 8 °C for short periods. For special applications, storage under argon or nitrogen may be preferred.

[9.] Donbrow, M., et al., Autoxidation of polysorbates. J. Pharm. Sci., 67, 1676-1681 (1978).

While this is not a very specific time span, it clearly indicates that TWEEN solutions are not long-term stable. If you need to store it, then in a fridge, protected from light and preferentially under an inert atmosphere for a few days max.

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    $\begingroup$ If you do this be sure to leave the date the solution was prepared on the bottle. $\endgroup$
    – Waylander
    Aug 15 at 8:59

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