摘要
提出了一种褪色光度法测定Cr^(3+)的新方法。新的叠氮试剂3-(苯偶氮苯)-1-三氮烯苯甲酸钠(PTBAS)在NaOH-Na_2B_4O_7缓冲液中,在表面活性剂OP的存在下,与Cd^(2+)反应后形成一种橙红色的络合物。测定Cd^(2+)时,当有微量Cr^(3+)共存时,络合物吸光度值明显降低,利用这种现象可以间接测定Cr^(3+)。测得Cr^(3+)的表观摩尔吸光系数ε=1.12×10~5,线性范围为0～0.4μg·ml^(-1)。方法选择性很高,很多常见离子不干扰测定,可直接用于水样中Cr^(3+)的测定。
A new photometric method for the determination of Cr3+ has been developed based on the decolouration effect. A new azide reagent-PTBAS reacts with Cd2+ to form an orange-red complex in the precence of noninic surfactant (OP) in NaOH-Na2B4 O7 buffer solution of pH 11.4. The value of absorption reduces distinctly when trace Cr3+ exists . Cr3+ can be determined indirectly by this reaction. Beer' s law is obeyed up to 0-0. 40μg ?ml-1 of Cr3+ with an apparant molar absorptivity of 1.12 × 105. The method is of high selectivity. Many common ions do not interfere and can be used to determine Cr3+ directly in water sample.
出处
《理化检验（化学分册）》
CAS
CSCD
北大核心
1996年第2期79-81,共3页
Physical Testing and Chemical Analysis(Part B:Chemical Analysis)
基金
国家自然科学基金
国家教委博士点专项基金资助课题
关键词
叠氮试剂
PTBAS
铬
光度法
水
Azide Reagent (PTBAS) Cr3+ Decolourizing spectrophotometry
