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以3-巯丙基三甲氧基硅烷(MPTS)为单一硅源,十六烷基三甲基溴化铵(CTMAB)存在下,采用一步简单混合,较方便地制得均匀、小粒径的有机硅纳米颗粒。采用原子力显微镜(AFM)、透射电子显微镜(TEM)对有机硅纳米进行表征,测得粒径约为2.5 nm。通过自组装法将其固定在金电极表面,得到均匀、高巯基含量的有机硅纳米修饰电极。采用方波溶出伏安法(SWV),考察了CTMAB浓度、Bi3+浓度、支持电解质、pH值富集电位及富集时间等参数对铅溶出信号的影响。结果表明:在0.2 mol/L HAc-NaAc(pH 5.0)缓冲溶液中,-1.0V电位下富集10 min,Pb2+溶出峰电流与浓度分别在5.0～500×10-12mol/L;2.5～250×10-9 mol/L和250～1250×10-9 mol/L范围内呈线性关系,最低检出浓度为5.0×10-12mol/L。利用本方法测定了实际水样中铅的含量,并与原子荧光光谱法进行对比,结果一致。
Using 3-mercaptopropyltrimethoxysilane (MPTS) as a single source of silicon and cetyltrimethylammonium bromide (CTMAB) in the presence of one-step simple mixing, it is easier to obtain uniform, small particle size Silicone nano-particles. Silica nano-particles were characterized by atomic force microscopy (AFM) and transmission electron microscopy (TEM). The particle size was about 2.5 nm. By self-assembly method to be fixed on the surface of the gold electrode, to obtain a uniform, high content of silicone modified nano-electrode. Square wave stripping voltammetry (SWV) was used to investigate the effects of CTMAB concentration, Bi3 + concentration, supporting electrolyte, pH-enriched potential and enrichment time on lead dissolution signal. The results showed that the peak current and the concentration of Pb2 + in the solution of 0.2 mol / L HAc-NaAc (pH 5.0) were enriched at -1.0 V for 10 min, and the peak current and concentration of Pb2 + were 5.0-500 × 10-12 mol / L, × 10-9 mol / L and 250 ~ 1250 × 10-9 mol / L, the lowest detection concentration was 5.0 × 10-12mol / L. The method was used to determine the amount of lead in water sample and compared with atomic fluorescence spectrometry. The results were consistent.