1,5-二(2-羟基-5-氯苯)-3-氰基甲月替光度法测定茶叶中微量钴  

Spectrophotometric Determination of Tracing Cobalt in Tea with 1,5-bi(2-hydroxy-5-chlorobenzene)-3-cyanoformazane

作　　者：金文斌[1] 

机构地区：[1]南通职业大学化学与生物工程学院,江苏南通226007

出　　处：《南通职业大学学报》2016年第2期91-93,共3页Journal of Nantong Vocational University

摘　　要：研究了微量元素钴的分光度测试法。在p H值为9的氨水-氯化铵缓冲溶液中,以复合微乳液聚乙二醇辛基苯基醚-溴代十六烷基三甲胺(OP10-CTMAB)为介质,钴与1,5-二(2-羟基-5-氯苯)-3-氰基甲月替(HCPCF)形成稳定的络合物;测得最大吸收波长位于670 nm处,表观摩尔吸光率为1.1×105(L·mol^(-1)·cm^(-1));结果表明,钴(Ⅱ)含量在0~0.4 mg/L范围内符合比尔定律,线性回归方程为A=0.077 9+0.055 9ρ,相关系数为0.999 1。方法用于茶叶中微量钴的测定,相对标准偏差为1.5%~1.9%,加标回收率在97%~105%之间,达到预期效果。This paper studies the spectrophotometric method for the determination of tracing element cobalt.1,5-bi（2-hydroxy-5-chlorobenzene）-3-cyanoformazane（HCPCF） reacts with cobalt in Ammonia-ammonium chloride buffer solution of p H 9. In the presence of Microemulsion octyl polyethylene glycol phenyl ether cetyltrimethylammonium bromide（op-10-CTMAB）, Cobalt and 1, 5-bi（2- hydroxy-5- chlorophenyl）-3- cyano formazan（HCPCF） form a stable complex. Based on this, a method for determination of cobalt is established by spectrophotometry. The maximum absorption wavelength is 670 nm and molar absorptivity is1.1×105（L·mol-1·cm-1）. Beer＇s law is obeyed when the content of cobalt（II） ranges from zero to 0.4 mg/L-1.The linear regression equation is A = 0.0779 ＋ 0.0559ρ, and the correlation coefficient is 0.9991. The method is applied to the determination of cobalt in tea samples. The relative standard deviation is from1.5% to 1.9%.The recoveries are between 97% and 105%.

关 键 词：1 5-二(2-羟基-5-氯苯)-3-氰基甲月替 分光光度法 茶叶 钴 

分 类 号：O657.32[理学—分析化学]