The invention relates to methods of separating Trolox isomers (R)-Trolox and (S)-Trolox, comprising: (a) contacting a mixture of (R) and (S)-Trolox with a resolving agent selected from the group consisting of (1S,2S)-(+)-Pseudoephedrine, (R)-(+)-2-Amino-3-phenyl-1-propanol, (1R,2R)-(−)-Pseudoephedrine, and (S)-(−)-2-Amino-3-phenyl-1-propanol, wherein the resolving agent forms a solid salt with one of (R)-Trolox and (S)-Trolox, and substantially does not form a solid salt with the other and (b) separating the solid salt from the Trolox isomer that did not form the solid salt with the resolving agent.