摘要
研究了Cu（Ⅱ）-4-（2-吡啶偶氮）-间苯二酚-OP高灵敏显色反应,结果表明,在pH=5.6的HAc-NaAc缓冲溶液中,有非离子表面活性剂OP存在时,Cu（Ⅱ）与4-（2-吡啶偶氮）-间苯二酚形成的有色络合物最大吸收波长位于512 nm处,表观摩尔吸光系数达7.27×10^4L/（mol.cm）,铜含量在0-30μg/25mL范围内服从比尔定律,络合物组成比为c（Cu（Ⅱ））∶c（PAR）=1∶2.加入抗坏血酸和柠檬酸盐等可消除Fe3＋、Co^2＋、Ni^2＋等离子的影响.该方法应用于食品、茶叶中微量铜的测定,相对标准偏差小于7%,回收率在96.8%-106%.
The high sensitive reaction of 4-（2-pyridylazo） -resorcinol with copper（ Ⅱ ） is studied. In the presence of emulsifier OP, copper （Ⅱ） reacts with 4- （2-pyridylazo） - resorcinol to form a stable complex with molax ratio of 1：2 in buffer solution of HAc-NaAc at pH 5.6. The maximum absorption of the complex is 512 nm and the apparent molar absorptivity is 7.27 × 10^4 L · mol^-1 · cm^-1. Beer＇s law is obeyed in the range of 0 -30 μg/25mL for copper. The influence of coexistent ions Fe^3＋ , Co^2＋ , Ni^2＋ and V （ V ） is avoided by adding ascorbic acid and citrate as the masking agent. The method can be applied to the determination of trace copper in the biological samples, including food and tea. The relative standard deviation is under 7%, the recorveries are 96. 8% - 106%.
出处
《桂林工学院学报》
北大核心
2007年第4期576-578,共3页
Journal of Guilin University of Technology
基金
广西自然科学基金资助项目(桂科自0679005)
