In the spectrophotometric determination of Alumina in cement, after the acidic opening of the Teflon bomb samples, the Al 3+ ion is complexed with 8-hydroxyquinoline (oxine) and extracted in chloroform. After the distribution of the oxynates, the aluminum content is determined by Alizarin S (Alizarinsulfonic acid sodium salt), which forms a red-yellowish complex, stable at pH 4.6
