Calcium complexing dyes and their use in analytical compositions,
申请人:Eastman Kodak Company
公开号:US04795712A1
公开(公告)日:1989-01-03
Novel chromogenic derivatives of 1,2-bis-(o-aminoaryloxy)ethane-N,N,N',N'-tetraacetic acid are useful for the determination of calcium ions in both solution and dry assays. These compounds comprise a dye moiety which is directly conjugated to the acetic acid substituted-nitrogen atom and which enables the compounds to exhibit maximum absorbance at a wavelength generally greater than 400 nm before complexation. When the compounds are complexed with calcium ions, the absorbance shifts to a shorter wavelength.