摘要
研究了溴化十六烷基三甲基铵(CTMAB)和正丁醇、正庚烷、水4组分构成的微乳液对铬天青S与铜(Ⅱ)显色反应的增敏作用,建立了测定大米中痕量铜(Ⅱ)的分光光度新方法。结果表明,在pH=6.00的NaH2PO4-NaAc缓冲溶液介质中,铜(Ⅱ)与铬天青S形成蓝绿色配合物,λmax=604nm,表观摩尔吸光系数为6.608×104L.mol-1.cm-1,在0—1.2mg/L范围内吸光度与Cu2+浓度呈良好的线形关系,线性回归方程为:A=-0.01475+0.39036V,相关系数为r=0.9996。应用该方法对大米中的铜进行测定,相对标准偏差RSD=2.8%,加标回收率为97%—104%。结果表明,该方法具有较高的灵敏度、准确度与精密度,适合大米中痕量铜的测定。
A new method to determine the trace copper in rice was established based on the sensitizing action of microemulsion（cetytrimethayl ammonium bromide,butanol,heptanol and water）in the chromogenic reaction of CAS with copper（Ⅱ）.Cu^2＋ reacts with CAS to form a cyan complex in the NaAc-NaH2PO4 buffer solution of pH6.00 with excess amount of microemulsion with a apparent molar absorption coefficient 6.608×10^4L·mol^-1·cm^-1 at 604nm.A linear range is from 0 to 1.2mg/L with the regression equation of A=-0.01475＋0.39036V,and correlation coefficient of 0.9996.The method is highly sensitive,accurate,and precise,and was applied to the determination of copper in rice with standard addition recoveries of 97%—104% and RSD=2.8%.
出处
《光谱实验室》
CAS
CSCD
2007年第6期1017-1021,共5页
Chinese Journal of Spectroscopy Laboratory
基金
新乡市科技发展计划项目(06G106)
河南科技学院青年骨干教师资助计划(200610415)
