论文部分内容阅读
提出一种利用纳米铜粒子吸附光度法定量检测微量三聚氰胺含量的方法。以DMF为还原剂,合成了粒径为3nm的纳米铜粒子;将合成所得的纳米铜与三聚氰胺均匀分散在乙二醇溶剂中,配制成不同浓度的三聚氰胺-纳米铜混合液,采用紫外-可见分光光度计检测其吸光度值,建立吸光度-三聚氰胺浓度之间的定量关系,探究纳米铜浓度及反应时间对体系的影响。结果表明:纳米铜对三聚氰胺具有很强的吸附,这种吸附作用通过化学络合作用使其溶解度提高;在UV-Vis吸收光谱中表现为:纳米铜的特征吸收峰位没有发生变化,但吸光度显著下降;其吸附作用时间需18 min以上。在三聚氰胺浓度较小时,吸光度与浓度呈现良好的线性关系,这种线性范围随着纳米铜溶胶的浓度增加而扩大,当纳米铜溶胶浓度为0.005 mol/L时,A-c线性范围为0~1.00 ppm;当纳米铜溶胶浓度为0.008 mol/L时,A-c线性范围扩大到6.00 ppm;经计算,该方法的检出限为0.015 ppm,回收率达到97%~99%,表明这种方法能够准确检测微量三聚氰胺的含量。
A method for the quantitative determination of trace melamine by nano-copper particle adsorption spectrophotometry was proposed. Nano-copper particles with a particle size of 3nm were synthesized by using DMF as reductant. The synthesized copper nanoparticles and melamine were uniformly dispersed in ethylene glycol solvent to prepare different concentrations of melamine-nano-copper mixed solution. UV- Spectrophotometer detection of absorbance values, the establishment of quantitative relationship between absorbance - melamine concentration, to explore the effect of nano-copper concentration and reaction time on the system. The results show that: nano-copper has a strong adsorption of melamine, this adsorption through the chemical complex to make its solubility; in the UV-Vis absorption spectra showed: nano-copper absorption peaks did not change, but the absorbance Significantly decreased; the adsorption time required for 18 min or more. When the concentration of melamine is small, the absorbance shows a good linear relationship with the concentration. This linear range expands with the concentration of nano-copper sol. When the concentration of nano-copper sol is 0.005 mol / L, the linear range of Ac is 0 ~ 1.00 ppm ; When the concentration of nano-copper sol is 0.008 mol / L, the linear range of Ac is expanded to 6.00 ppm. The detection limit of this method is 0.015 ppm and the recovery rate is 97% -99%, which shows that this method can accurately detect Trace amount of melamine.