The present invention relates to a mycotoxin adsorbent, as well as to the process for the preparation of said adsorbent. The adsorbent of the invention is based on the combination of an organic silicate with an amorphous structure and dodecylamine, that is to say, a primary amine having an apolar, linear, aliphatic long-chain of twelve carbon atoms. The invention also relates to the use of said adsorbent in feeds for the adsorption of mycotoxins, especially for the adsorption of mycotoxins such as aflatoxins, zearalenone, ochratoxin A or fumonisin B1. Furthermore, the invention relates, on the one hand, to a feed additive comprising said adsorbent and, on the other hand, to the feeds comprising said additive.