[LiAl_2(OH)_6]Cl·yH_2O was prepared by co-precipitation. The competitive intercalation of geometric isomers of hydroxybenzoic acid into the interlayer of layered double hydroxides (LDHs) was studied by the reaction of [LiAl_2(OH)_6]Cl·yH_2O with various mixtures of o-hydroxybenzoic acid, m-hydroxybenzoic acid and p-hydroxybenzoic acid. Powder X-ray diffraction (XRD) results confirmed the intercalation of the isomers, and high performance liquid chromatography (HPLC) was used for the quantitative study. The order of the preferential intercalation of the three isomers was found to be: o-hydroxybenzoic acid (1,2-C_7H_6O_3)》 p-hydroxybenzoic acid (1,4-C_7H_6O_3) > m-hydroxybenzoic acid (1,3-C_7H_6O_3).
