锰(Ⅱ)-纳米银体系共振散射光谱法检测痕量过氧化氢  

Determination of Trace Hydrogen Peroxide by Resonance Light Scattering Method Based on Mn(Ⅱ)-Silver Nanoparticles System

作　　者：唐宁莉[1] 陈永宁[1] 张容珲 覃温露[1] 

机构地区：[1]桂林理工大学化学与生物工程学院,广西桂林541004

出　　处：《分析测试学报》2016年第9期1094-1099,共6页Journal of Instrumental Analysis

基　　金：国家自然科学基金(21165008)

摘　　要：利用纳米银(AgNPs)作为共振散射探针,根据反应前后纳米银聚集状态改变所引起的体系的共振散射信号的变化,对H_2O_2进行定量检测。采用硼氢化钠还原法,在柠檬酸三钠保护下将银从硝酸银中还原,合成了平均粒径约为4 nm的银纳米微粒。Mn^(2+)和覆盖在纳米银表面的柠檬酸根负离子络合诱导纳米银聚集,导致体系的共振散射强度增强;当体系中存在H_2O_2时,H_2O_2和Mn^(2+)发生类Fenton反应生成Mn^(3+)和羟基自由基(·OH)。Mn^(3+)和纳米银不能形成稳定的络合物,·OH氧化蚀刻纳米银,两种反应共同导致纳米银的聚集程度减弱,体系的共振散射信号强度相应减弱,据此建立了一种检测痕量H_2O_2的共振散射光谱新方法。在最佳条件下,波长411 nm处,体系的共振散射强度变化值(ΔI)与H_2O_2浓度在7.88×10^(-8)~1.418×10^(-5)mol/L范围内呈线性关系,相关系数为0.996 7,检出限为4.04×10-8mol/L。该方法应用于湖水和雨水中H_2O_2的检测,结果满意。According to the system resonance light scattering intensity will change with the variation of AgNPs aggregation state before and after the reaction,a novel resonance light scattering（RLS） method for the quantitative determination of trace hydrogen peroxide was developed using silver nanoparticles（AgNPs） as the resonance scattering probe.The silver nanoparticle with an average particle size of 4 nm was synthesized through the reduction of silver nitrate by sodium borohydride,using trisodiumcitrate as the protecting agent.The detection of H2O2 mechanism was based on that Mn2＋ was chelated by the citrate covering on the surface of the silver nanoparticles, inducing the aggregation of AgNPs with increasing of resonance scattering intensity of the system.When H2O2 was added to the system,Mn2＋ participated in Fenton-like reaction with H2O2 producing Mn3＋ and hydroxyl radical（？OH）.The complexation reaction of citrate on the surface of the AgNPs with Mn3＋ formed unstable complexes,and ？OH oxidatively etched AgNPs.Both of the two reactions could result in non-aggregation of AgNPs as well as relatively weakening resonance scattering intensity of the system. Under the optimal conditions,the resonance light scattering intensity of system at 411 nm was decreased linearly with concentration of H2O2 over the range of 7.88×10-8-1.418×10-5 mol/L,with a correlation coefficient of 0.9967 and a detection limit of 4.04×10-8 mol/L. This method was applied in the analysis of hydrogen peroxide in the lake and rain water samples with satisfactory results.

关 键 词：过氧化氢 纳米银 共振散射 类FENTON反应 

分 类 号：O657.3[理学—分析化学] TQ123.6[理学—化学]