meso-四(3,5-二溴-4-羟基苯基)卟啉.pdf

View Online Synthesis of meso-tetra-(3,5-dibromo-4-hydroxylphenyl)- porphyrin and its application to second-derivative spectrophotometric determination of lead in clinical samples a a a b Zaijun Li , Zhengzhong Zhu , Tang Jan and Jiaomai Pan a Department of Chemical Engineering, Wuxi University of Light Industry, Wuxi 214036, China b Department of Chemistry, East China Normal University, Shanghai 200062, China Received 10th May 1999, Accepted 24th June 1999 i 8 9 6 3 0 A new very sensitive and selective chromogenic reagent, meso-tetra-(3,5-dibromo-4-hydroxylphenyl)porphyrin 9 a / [T(DBHP)P], was synthesized and studied for the determination of trace lead in detail. In 0.10 mol l1 NaOH 9 3 0 medium, lead reacts with T(DBHP)P to form a 1 2 yellow complex, which gives a maximum absorption at 479 1 . 0 nm; 0–0.48 g ml1 Pb(ii) obeyed Beer’s law. The molar absorptivity of the complex and Sandell’s sensitivity are 1 : i 5 1 1 2 o 2.5 10 l mol cm and 0.000812 g cm , respectively. Second-derivative spectrophotometry is better than d | g conventional spectrophotometry in sensitivity and selectivity, and its limit of quantification, limit of detection and r o 1 1 c. relative standard deviation are 0.70 ng ml , 0.21 ng ml and 1.0%, respectively. Ca (3250-fold), Mg s r s. (2000-f