コハク酸-ヘキサミンを緩衝剤とするフッ素のアリザリンコンプレクソン迅速光度定量  [in Japanese] A simple and rapid method for photometric determination of fluoride with alizarine complexone.  [in Japanese]

A simple and rapid method for the determination of trace fluoride was invegtigated using alizarine complexone (ALC). The rate of the color reaction of fluride with the lanthanum chelate of ALC is enhanced by the succinic acid-hexamethylenetetramine buffer. And this buffer reagent were used as the composite reagent with La-ALC. To the sample solution, 5ml of La-ALC mixed solution, 2ml of buffer solution (pH4.6) [or 5ml of 2.5% solution of composite reagent], and 5ml of acetone were added, and the mixture was diluted to 25ml with water. After 15 min, the absorbance was measured at 620nm against the reagent blank. The color was fully developed within 15 min and stable for at least 24 hours. The absorbance showed a constant value when acetone was present at concentrations from 15 to 40 percent by volume. The composite reagent was stable for at least 9 months. The preparation of the reagent solution is easy, and (1〜30) μg of fluoride can be determined rapidly.