A new spectrophotometric method for the determination of calcium has been studied,based on the discoloring reaction of calcium and picramazo-chromotropic acid in pH 11.

• 研究了苦安酸偶氮变色酸与钙的褪色反应,试验了最佳反应条件,建立了测定水中钙含量的褪色光度分析方法。