Di(mu-) hydroxyl. tetramethionine-chelated dichromium (III) as well as preparation method and application thereof

The invention discloses a di(mu-) hydroxyl. tetramethionine-chelated dichromium (III) as well as a preparation method and application thereof. Di(mu-) hydroxyl. tetramethionine-chelated dichromium (III) has the following molecular formula of C20H42N4O10S4Cr2. The preparation method comprises the following steps: (1) dissolving DL-methionine and inorganic chromium (III) salt in an aqueous solution of ethanol and carrying out reflux heating; 2) adjusting the pH and carrying out reflux reaction; and (3) cooling, crystallizing, filtering and drying to obtain di(mu-) hydroxyl. tetramethionine-chelated dichromium (III). The invention also discloses application of di(mu-) hydroxyl. tetramethionine-chelated dichromium (III) as a feed additive. Di(mu-) hydroxyl. tetramethionine-chelated dichromium (III) is a binuclear complex and is simple in preparation method, easily available in raw materials and low in cost; and the product is high in purity and stable in quality and the technology has a potential for large-scale industrial production. In addition, di(mu-) hydroxyl. tetramethionine-chelated dichromium (III) can be used as the animal feed additive and is used for supplementing chromium in animal dietary and improving growth performance and immune properties of animal body.