摘要
利用非离子表面活性剂存在下的胶束增溶、增敏作用,研究和建立了在吐温—20胶束体系中分光光度法测定微量铜的方法。在吐温—20的存在下,于pH8.5的缓冲介质中,铜(Ⅱ)与铜试剂形成棕黄色配合物,其最大吸收波长为453nm,表观摩尔吸收系数为1.35×10~4L.mol.cm^(-1);在25ml溶液中铜(Ⅱ)含量为0～60μg范围内遵守比耳定律,配合物至少可稳定48小时。方法具有良好的选择性,应用于植物中微量铜的测定,结果满意。
A spectrophotometry for the determination of trace copper has been studied in micelle medium of non-ionic surfactant Tween-20. Copper (II) reacts with sodium diethylddthi-ocarbamate in the presence of Tween-20 in a buffer solution of pH 8. 5 to form a brown yellow complex. The apparent molar absorptivity is 1. 35x104 L mol-1 cm-1 at 453nm, and it was stable for more than 48h. Beer's law is obeyed in the range of 0~ 60u g Cu(II) per 25mL. The selectivity of the reaction is improved by the addition of EDTA and ammonium citrate as masking agents. The method has been used for the determination of trace copper in plant materials with satisfactory results.
出处
《植物营养与肥料学报》
CAS
CSCD
1996年第2期175-180,共6页
Journal of Plant Nutrition and Fertilizers
关键词
铜
测定
分光光度法
铜试剂
叶温-20
植物
Copper determination Micellar solubilization spectrophotometry Sodium diethyldithiocarbamate Tween-20 Plant
