【摘要】 聚2-丙烯胺缩3－（4-甲酰基苯偶氮）-4，5-二羟基-2，7-萘二磺酸（PA-FPNS）在pH11．5的磷酸盐介质中．与镁（Ⅱ）形成一蓝色络合物，其最大吸收位于604nm，表观摩尔吸光系数ε=5．7×104L·mol-1·cm-1，线性范围为0．01～0．35mg／L，至少稳定12h。考察了30多种共存离子的影响，在所测样品中它们不干扰，无需掩蔽或分离即可直接测得其中的镁。更多还原

【Abstract】 PA-FPNS, a condensed product of polyallylamine (PA) and 3-(4-formylpheny-lazo)-4, 5-dihydroxy-naphthalene-2, 7-disulfonic acid (FPNS), reacts with magnesium selectively in alkaline media to form a water-soluble blue complex. The molar absorptivity (ε) of the compIex is 5. 7×104L mol -l· cm-1 at 604 nm, and Beer’s law is obeyed over the range of 0.01~0.35 mg/L for magnesium. A fast and simple spectrophotometric method for the determination of magnesium has been developed, and applied to biololgical fluids, foods, and potables samples without separation or using masking agents.更多还原