在十六烷基三甲基溴化铵(CTAB)存在下,硝酸银与没食子酸丙酯在碱性介质中发生还原反应,制得纳米银;考察了反应时间、氢氧化钠浓度、反应温度以及PG/Ag+浓度比等条件对合成纳米银粒子的影响.利用扫描电子显微镜对纳米银颗粒形貌和尺寸进行了表征,结果表明获得了分散性良好的球形粒子.实验中还发现在还原银离子制备纳米银过程中会产生强烈的表面等离子共振峰,用紫外-可见光谱监测制备过程得到的纳米银紫外吸收带范围为400~450 nm,最大吸收波长为420 nm,光谱强度与抗氧化剂的浓度成正比.将纳米银的这一特性用于定量测定没食子酸丙酯(PG)、二丁基羟基甲苯(BHT)、叔丁基对羟基茴香醚(BHA)和叔丁基对苯二酚(TBHQ)等抗氧化剂,所得检出限分别为0.0752,0.1242,0.0693和0.0701 mg/L,线性范围分别为0.2~1.8,0.2~3.4,0.2~3.4和0.2~3.0 mg/L.
Silver nanoparticles were synthesized based on the chemical reduction between propyl gallate(PG) and silver nitrate in the presence of eetyltrimethylammonium bromide (CTAB). The experimental conditions, including reaction time, concentration of sodium hydroxide, temperature and concentration ratio of PG to Ag+ , were investigated. The silver nanoparticles were characterized by scanning electron microscope (SEM) , and it showed that the nanoparticles were spherical shape. The reduction of Ag+ to silver nanoparticles produced very intense surface plasmon resonance peak of silver nanoparticles. An absorbance band in the range of 400-450 nm was observed by UV-Vis spectrophotometry with a maximum absorbance wavelength of 420 nm. The plas- mon absorbanee of silver nanopartieles allows the quantitative determination of some antioxidants, such as PG, butylated hydroxytoluene ( BHT), butyl hydroxy anisole (BHA) and tertiary butyldroquinone (TBHQ). Their detection limits were 0. 0752, 0. 1242, 0. 0693 and 0. 0701 rag/L, respectively; and their corresponding linear ranges were 0. 2--1.8, 0. 2--3.4, 0.2--3.4 and 0. 2--3.0 mg/L, respectively.