表面增强拉曼光谱内标法测定亚胺硫磷农残含量  

Quantitative Determination of Phosmet Pesticide Residue by Surface-enhanced Raman Scattering with Internal Standard Method

作　　者：刘江美[1] 严丽萍[1] 刘文涵[1] 滕渊洁[1] 

机构地区：[1]浙江工业大学化学工程学院,绿色化学合成技术国家重点实验室培育基地,浙江杭州310032

出　　处：《分析测试学报》2016年第5期605-608,共4页Journal of Instrumental Analysis

基　　金：浙江省公益性技术应用研究(分析测试)计划项目(2015C37068);浙江省科技计划重大科技专项(2013C1152)

摘　　要：采用柠檬酸钠还原法制备了具有表面增强拉曼散射（SERS）活性的纳米银溶胶，进而利用亚胺硫磷（Phosmet）吸附于纳米银胶表面使其产生SERS光谱，并对Phosmet的含量进行了测定。选择硫氰化钾（KSCN）为内标物，通过不同浓度亚胺硫磷的拉曼特征峰（S—P伸缩振动503cm^-1）与内标物SCN-的特征峰（2120cm^-1）峰高的相对强度比，建立线性回归方程。结果表明：Phosmet的线性范围为5．0×10^-71．2×10^-5mol·L^-1，相关系数为0．9978；按7次空白实验所对应响应值，。的3倍标准偏差，计算得检出限为2．82×10^-7mol·L^-1；回收率为88．7％～110．2％，相对标准偏差（RSD）不大于8．0％。方法测定简单、操作方便、内标物干扰小，可应用于其他农残的分析测定。A novel surface-enhanced Raman scattering（SERS） method was established for the quan- titative determination of trace phosmet via potassium thiocyanate（KSCN） serving as an internal stand- ard. The silver colloid with high SERS activity, a kind of SERS substrate, was prepared by sodium citrate reduction. The enhanced Raman signal of phosmet on silver colloid was proved through compa- ring the normal Raman spectra of silver colloid and phosmet with SERS spectrum of trace phosmet. The concentrations of phosmet could be determined with the corresponding SERS spectra produced by adsorption of phosmet on nano silver colloid surface, while KSCN was selected as the internal stand- ard. The strongest SERS signal of phosmet appeared at 503 cm^-1, and was assigned to the S--P stretching vibration, so it was considered as quantitative peak. The range linear of 5.0 × 10^ -7 - 1.2 × 10^-5 mol·L^-1 was obtained for concentrations of phosmet divided by ratio of S--P stretching vibration at 503 cm^-1 and SCN- characteristic peak at 2 120 cm^-1 The linear correlation coefficient （r） was 0. 997 8, and the detection limit（S/N =3） was 2.82 ×10^-7 mol·L^-1 Furthermore, the proposed method was applied in the detection of simulated water sample, with recoveries of 88.7% - 110. 2% and relative standard deviations（RSD） not more than 8.0%. The interference experiments were also considered by the detection of some inorganic ions and the background SERS signal of simu- lated water sample. With the advantages of simplicity, easy operation and no interference of internal standard substance, the proposed method could be extended to the determination of other pesticide molecules.

关 键 词：表面增强拉曼光谱 亚胺硫磷 内标法 银溶胶 

分 类 号：O657.3[理学—分析化学] F767.2[理学—化学]