摘要
本文研究了Co(Ⅱ)-5-Br-PADNm络合物的极谱行为.在0.15mol/l NaOH溶液中,当有0.5％盐酸羟胺存在时,Co(Ⅱ)-5-Br-PADNm络合物在-0.90V呈现一灵敏络合物吸附波,利用此波可测定低至5.0×10^(-9)mol/l的钴.用均匀设计-单纯形法选择了最佳底液条件,应用电毛细曲线、直流极谱、脉冲极谱,i-t曲线、交流阻抗和循环伏安等多种电化学技术研究了Co(Ⅱ)-5-Br-PADNm的电极反应机理;提出了用5-Br-PADNm借示波极谱法测定痕量钴的方法,用于茶叶中钴的测定得到满意结果.
The polarographic and other electroanalytical behavior of cobalt(II) complex with 4-(2-(5-bromo-pyridyl)azo)-l,3-dihydioxynaphlhalene (5-Br-PADNm) have been, studied. In 0.15mol/L sodium hydroxide solution containing 0.5% hydroxyl-atnine hydrochloride the Co( II )-5-Br-PADNm complex gives a sensitive pola-rographic wave (P3) at -0.90V, which was used for the determination of the trace amount of cobalt down to 5.0 × 10-9mol/L. The composition of background eleclrol te solution was optimized by using homogeneity-design simplex procedures. D.C polarography and cyclic voltammetry showed that the polarographic wave of Co(II)-5-Br-PADNm complex is reversible. The fact that the limit current of P3 was proportional to the height of mercury volumn indicated that the Co( II )-5-Br-PADNm complex was adsorbed at mercury electrode. This was further confirmed by the electrocapillary curves. The AC impedance behavior has also been studied. A single-sweep polarographic procedure for determination of trace amount of cobalt using 5-Br-PADNm has been worked out.
出处
《环境化学》
CAS
CSCD
北大核心
1990年第4期49-54,共6页
Environmental Chemistry
