中文摘要：

在聚乙烯吡咯烷酮（PVP）做保护剂的条件下,利用维生素C、维生素E的还原性制备纳米银。考虑反应时间、温度、NaOH浓度、PVP浓度对制备的影响,同时结合响应面方法对条件进行优化。采用扫描电子显微镜和粒度仪对纳米银的形貌和尺寸进行表征,并利用傅里叶红外光谱（FT-IR）表征和分析纳米银的形成。结果表明：维生素C（维生素E）在反应温度为55℃（80℃）、NaOH和PVP浓度分别是2.2×10（-3）mol·L（-1）（1.6×10-4mol·L（-1））和2.4×10（-5）mol·L（-1）（2.0×10-4mol·L（-1））的条件下制备出粒径较小、分散性良好的纳米银。用紫外-可见光谱监测发现,纳米银在400450nm处会产生强烈的表面等离子共振峰,吸收峰强度与维生素C或E的浓度成正比。将纳米银这一特性用于定量检测维生素C和维生素E的含量,其检出限分别是0.17和0.63mg·L（-1）,线性范围分别为0.45.0和0.99.5mg·L（-1）。

英文摘要：

Silver nanoparticles were prepared with silver nitrate and reducer ascorbic acid（ VC） or tocopherol（ VE） under the existence of protecting reagent polyvinyl pyrrolidone（ PVP）. The experimental conditions,which including reaction time,temperature,the concentrations of Na OH and PVP,were studied based on the absorption of silver nanoparticles combined with response surface methodology. The scanning electron microscope（ SEM） and partical size analyzer showed the properties such as dispersed well,smaller particle size and uniform distribution,and FT- IR further analyzed the formation of silver nanoparticles. The results indicated that the temperature of 55℃（ 80 ℃） and the concentrations of NaOH at 2. 2 × 10（-3）mol·L（-1）（ 1. 6 × 10（-4）mol·L（-1）） and PVP at 2. 4 ×10（-5）mol·L（-1）（ 2. 0 × 10（-4）mol·L（-1）） were the optimum to synthesizing the nanoparticles,which were smaller particle size and dispersed well. The silver nanoparticles showed UV- vis absorption band in the range of 400- 450 nm,and the concentration of ascorbic acid or tocopherol was proportional to the spectral intensity of silver nanoparticles. According to this characters,it could be applied to quantitatively detect the ascorbic acid or tocopherol. The detection limit were 0. 17 and 0. 63 mg·L（-1） for ascorbic acid and tocopherol,respectively,and their corresponding linear ranges were 0. 4- 5. 0 and 0. 9- 9. 5 mg·L（-1）,respectively.