表面活性剂-膜富集-紫外可见漫反射光谱法测定水中的痕量铅

发布时间：2018-04-04 04:29

  本文选题：表面活性剂　切入点：膜富集　出处：《光谱学与光谱分析》2015年07期

【摘要】：提出了结合表面活性剂、膜富集和紫外可见漫反射光谱测定水中痕量铅的方法。在pH 8.5的氨水氯化铵缓冲溶液中,剧烈搅拌下,铅与双硫腙形成疏水性的红色络合物,该络合物能够被混合纤维素酯膜富集,并且在非离子表面活性剂聚氧乙烯月桂醚(Brij-30)的存在下,该络合物被混合纤维素酯膜富集的效率得到了很大提高,然后待膜自然干燥后直接测得膜表面的漫反射光谱。本文对表面活性剂类型、表面活性剂浓度、反应酸度、双硫腙浓度和反应时间等条件进行了优化。研究结果表明,在最佳实验条件下,最大吸收波长为485nm,在5~100μg·L-1范围内铅离子的浓度与其络合物的吸光度呈良好的线性关系,相关系数的平方R2为0.990 6,检出限为2.88μg·L-1。研究发现下列共存离子不干扰铅离子的测定:500倍的K+,Na+,Ca2+,Mg2+,NH4+,NO-3,Cl-,CH3COO-,SO2-4;10倍的Al 3+(10%的NaF进行掩蔽),Fe3+(10%的NaF和酒石酸钾钠进行掩蔽),Hg2+和Zn2+(10%的NaSCN和酒石酸钾钠进行掩蔽);同等浓度的Cd2+,Cu2+。采用本方法测定瓶装水中的痕量铅,结果与石墨炉原子吸收光谱法(GFAAS)测定的结果基本一致,加标回收率在95.4%~104.5%之间,标准偏差(SD)在0.5~1.5μg·L-1之间,说明本方法具有较好的准确性。本方法操作简单、灵敏度高,适用于瓶装水中痕量铅的测定。
[Abstract]:A method for the determination of trace lead in water with surfactant, membrane enrichment and UV-Vis diffuse reflectance spectroscopy was proposed.In pH 8.5 ammonium chloride buffer solution, lead and dithizone form a hydrophobic red complex, which can be enriched by mixed cellulose ester membrane.Moreover, in the presence of Nonionic surfactant polyoxyethylene lauryl ether (Brij-30), the enrichment efficiency of the complex by mixed cellulose ester film was greatly improved, and then the diffuse reflectance spectra of the film surface were measured directly after the film was dried naturally.The types of surfactants, the concentration of surfactants, the acidity of the reaction, the concentration of dithizone and the reaction time were optimized.The results show that under the optimum experimental conditions, the maximum absorption wavelength is 485 nm, and the concentration of lead ion has a good linear relationship with the absorbance of the complex in the range of 5 渭 g / L ~ (-1). The square R2 of the correlation coefficient is 0.990 6 and the detection limit is 2.88 渭 g / L ~ (-1).鐮旂┒鍙戠幇涓嬪垪鍏卞瓨绂诲瓙涓嶅共鎵伴搮绂诲瓙鐨勬祴瀹，

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