高效液相色谱-柱后衍生和质谱联用测定大米中氨基甲酸酯类农药残留量

研究了高效液相色谱-柱后衍生荧光检测和液质联用分别测定大米中14种和16种氨基甲酸酯类农药残留量的方法.二氯甲烷和丙酮的混和溶剂提取后,用柱后衍生荧光检测法和离子阱多级质谱联用法进行测定.柱后衍生荧光检测法检出限为20～50 μg/kg,离子阱多级质谱联用法检出限为10～20 μg/kg,添加平均回收率在70%～92%之间,RSD%在6.7%～12%.     

Stable Zinc-Based Metal-Organic Framework Photocatalyst for Effective Visible-Light-Driven Hydrogen Production

Herein, a new Zn-MOF material, [Zn(L1)(L2)], 1, was built successfully through a one-pot solvothermal method. The 3D MOF structure was determined by Single X-ray diffraction analysis, IR, and elemental analysis. A series of PXRD tests of 1 after being immersed in different solvents and pH solutions demonstrated the good stability of 1. Interestingly, this material displayed high catalytic activity for the visible-light-driven hydrogen generation under the illumination of white LED in pure water or a mixture of DMF and H₂O without additional photosensitizers and cocatalysts. Besides, the studies also showed that the catalytic activity changed constantly as well as the solvent ratio adjustment of DMF and H₂O from 4:6 to 2:8. Additionally, the catalytic activity reached the best value (743 μmol g⁻¹ h⁻¹) when the solvent ratio was 4:6. The heterogeneous nature and recyclability of the MOF catalyst, as well as several factors that affect the catalytic activity, were investigated and described in detail. Moreover, the photocatalytic mechanism for the hydrogen generation of 1 was also proposed based on the fluorescence spectra and UV-vis absorption.     

一种基于磁性纳米粒子PCR的高通量SNP分型方法

利用磁性纳米粒子PCR扩增(MNPs-PCR)和等位基因特异性双色荧光探针(Cy3, Cy5)杂交, 建立了一种单核苷酸多态性(SNP)分型的新方法. 应用该方法对9个样本MTHFR基因的C677T多态进行检测, 野生和突变型样本正错配信号比大于9.0, 杂合型正错配信号比接近1.0, 分型结果经测序验证. 此方法无须产物纯化、浓缩, 扫描分型结果快速、直观, 是一种操作简单、快速、高通量、高灵敏度的分型方法.     

多枝[1,3,4]-噁二唑衍生物的双光子吸收和光功率限幅特性

采用非线性透过率法测定了多枝[1,3,4]-噁二唑衍生物的双光子吸收性质. 测定了化合物的单光子荧光光谱和双光子荧光光谱, 在800 nm波长的激光激发下, 9-乙基-3,6-双{5-(4-叔丁基苯基)-[1,3,4] 噁二唑-2-苯乙烯基}-咔唑(3)和三-{5-(4-叔丁基苯基)-[1,3,4] 噁二唑-2-苯乙烯基-4-苯基}-胺(4)能够发出很强的蓝色和黄绿色双光子上转换荧光, 荧光峰分别位于485和547 nm. 这些多枝结构化合物的双光子吸收截面较大(数值超过104 GM), 并具有很强的光限幅效应. 多枝分子中重复单元的推拉电子结构和协同效应有效地增强了分子的双光子吸收性质.     

阴阳离子菁染料超快荧光动力学特性研究

采用飞秒荧光上转换技术,研究了阴阳离子菁染料及对应的阴离子和阳离子菁染料吸附在立方型和T型溴碘化银表面上形成J-聚集体的荧光衰减时间分辨特性,分析了几种菁染料增感体系的超快电子转移动力学过程及其对增感效率的影响.通过比较几种菁染料增感体系的荧光衰减特性,两种阴阳离子染料要明显快于阴离子染料、阳离子染料及二者的加合,说明阴阳离子染料聚集体到溴碘化银的电子注入速率较快,增感效果更好.对两种阴阳离子染料聚集体荧光衰减特性的比较,可以看出染料在T型颗粒溴碘化银上形成聚集体的荧光寿命更短,因而对T型颗粒的增感效果更好.染料Dye2的荧光衰减要快于染料Dye1,说明染料Dye2到溴碘化银的电子注入速率更快,增感效率更高.     

混合染料荧光选择性增强受激拉曼散射Stokes波

报道用不同混合比的罗丹明6G(R6G)和罗丹明B(RB)混合染料荧光选择性放大CCl₄和苯的受激拉曼散射不同阶次Stokes波。CCl₄二至五阶Stokes波分别被混合摩尔比为20∶2,20∶13及20∶40(R6g∶RB)的R6G和RB的混合染料荧光放大;一阶Stokes波强度被混合溶液削弱。这是由于到二至五阶Stokes波分别位于以上三种混合溶液荧光峰附近,并且都远离了R6G和RB的吸收峰,混合溶液的荧光增强作用大于吸收作用,因此这几阶Stokes被混合溶液荧光放大。而CCl₄的一阶Stokes位于RB吸收峰附近,又远离各混合溶液荧光峰,溶液的吸收作用大于荧光增强作用,导致一阶Stokes被混合溶液削弱。文章还报道了苯的一、二和三阶Stokes波分别被不同混合比的R6G和DCM的混合乙醇溶液放大,并预测了该方法应用前景。     

Study of Interaction of Berberine With Dna in the Presence of β -Cyclodextrin

In this paper, β -Cyclodextrin (β -CD) was used to study the interaction of berberine with DNA by the means of absorption spectrum and fluorescence spectrum. Experimental results showed that it was the isoquinolinic part that intercalated into the DNA double helix. And the value of the intrinsic binding constant K was 4.5 × 10³l/mol in the presence of β -CD and 1.1 × 10⁴l/mol in the absence of β -CD.     

Regioselective Arylation and Alkynylation of 2,3‐Dibromo‐1H‐inden‐1‐one by Suzuki?Miyaura and Sonogashira Cross‐Coupling Reactions

Suzuki? Miyaura reactions of 2,3‐dibromo‐1H‐inden‐1‐one afforded a wide range of arylated 1H‐inden‐1‐ones. Sonogashira cross‐coupling reactions gave alkynylated indenones. The reactions proceeded with very good regioselectivity in the less sterically hindered and more electron‐deficient position 3.     

能量色散型X射线荧光光谱法测定聚合物材料中镉和铅含量

提出了能量色散型X射线荧光光谱测定聚合物材料中镉和铅的测试分析方法及制样技巧。按照仪器分析条件测定同时含有镉和铅的6块不同浓度级别的标准物质来建立校准工作曲线,其线性范围分别在250ug·g-1、1100ug·g-1以内。镉和铅的方法检出限依次为4.7ug·g-1、4.1ug·g-1。该方法应用于测定欧洲标准物质ERM-EC680和ERM-EC681k,其镉和铅的实际测定值与标准物质证书的标称值相符,测定实际样品中的镉和铅的回收率介于90~110%。该方法测定标准物质和实际样品中镉和铅的精密度均小于10%。     

An HPLC method for the determination of selected amino acids in human embryo culture medium

A method for the determination of selected amino acids in culture medium using HPLC with fluorescence detection is described. Twenty hours after intra‐cytoplasmic sperm injection, one randomly selected zygote was transferred to the culture medium. After incubation (72 h after fertilization), the culture medium in which the embryo was incubated and blank medium was immediately stored at −80°C. Filtered medium samples were derivatized with ortho ‐phthalaldehyde (naphthalene‐2,3‐dicarboxaldehyde), forming highly fluorescent amino acids derivatives. Reverse‐phase columns (LichroCART, Purospher STAR RP_18e or Ascentis Express C₁₈) were used for the separation. The derivatives were analyzed by gradient elution with a mobile phase containing ethanol and sodium dihydrogen phosphate. The analytical performance of this method is satisfactory for all amino acids; the intra‐assay coefficients of variation were <10% and quantitative recoveries were between 95.5 and 104.4%. Changes in the levels of selected amino acids before and after human embryo cultivation were observed. After embryo incubation, the levels of all amino acids in the medium were increased, apart from aspartate and asparagine. After the cultivation of some embryos, amino acids which were not part of the medium were detected. Low amino acids turnover was observed in some embryos.