蛋白质的曙红Y-中性红逆向能量转移荧光法测定

在pH 2.35的B-R缓冲溶液中,酸性染料曙红Y(EY)与碱性染料中性红(NR)之间由于静电吸引能够发生有效的能量转移,使能量受体NR荧光增强,能量给体EY的荧光猝灭.在该体系中加入人血清白蛋白(HSA),由于竞争作用使得HSA的加入破坏了EY-NR间的能量转移,产生了明显的逆向反应,并且生成HSA-EY络合物,利用该络合物的荧光增加强度与HSA含量间的线性关系建立了一种测定微量血清蛋白的新方法.结果表明,血清蛋白工作曲线线性范围为0.6～12.0 mg/L;方法检出限为0.25 mg/L;6次平行测定相对标准偏差为1.94%～4.58%;回收率为96%～105%.该方法的稳定性好、选择性高,直接用于人血清试样中总蛋白含量的测定,实验结果与常用的双缩脲法基本一致.     

电解法测定微量水的研究

本文介绍电解法测定微量水的工作原理、电解池以及影响测量微量水的因素。提供了研究测量微量水的方法,以便制造性能可靠,测量准确的微量水份测定仪。     

DNA荧光探针-荧光素-中性红体系的研究

基于DNA对荧光素(FL)-中性红(NR)分子间荧光能量转移的抑制作用,以荧光素-中性红为荧光探针,考察该探针与DNA的结合反应,建立了准确测定DNA的新方法,在pH＝6.5条件下,hsDNA、ctDNA和smDNA的浓度与荧光素-中性红体系的荧光比值变化量Δ(Fd／Fa)成线性关系,响应线性范围分别为0．25-6．25μg／mL、0．10-5．00μg／mL、0．10-4．00μg／mL,0.025μg/mL和0．023μg／mL;分析测定了DNA合成样品,回收率91．3％-101．4％,相对标准偏差小于4．2％．     

A Fluorescence Polarization Immunoassay Procedure for Determining Dibutyl Phthalate in Water

Journal of Analytical Chemistry - We developed a fluorescence polarization immunoassay (FPIA) procedure for determining the dibutyl phthalate (DBP) plasticizer, a toxic technogenic environmental...     

The Energy of Interaction between Water Monolayer and Carbon Surface and the Determination of H-Bond Energy from the Isotherms of Water Desorption by Organic Molecules into an Aqueous Solution

It is proven that, when passing from a liquid into an adsorption phase on a carbon surface, the maximal number of H-bonds between water molecules decreases from four to three because of the screening of one unpaired electron of the oxygen atom of an adsorbed water molecule by aromatic rings of the carbon surface. An energy gain equal to the energy of one H-bond arises upon water desorption by organic molecules adsorbed from an aqueous solution. The ratio between the number of H-bonds of a group of water molecules, which is displaced into a solution by one organic molecule, in the solution and in the adsorption phase is independent of the number of molecules in this group and is, on the average, equal to 2.038 for all possible structures of H-bonds in both phases. The allowance for this ratio in the isotherm of water desorption into a solution and the introduction of a coefficient, which depends on the relative water content ( ) in the adsorption phase, in the form of into the equation of the desorption isotherm make it possible to determine the balance of the change in the Gibbs energy at the desorption equilibrium and the standard Gibbs energy = –1.76 kJ/mol of water desorption into a solution from a carbon surface. This value determined by an independent method is = –1.79 kJ/mol; i.e., both values are close to each other. The RTlnf energy of the additional H-bond, which is formed between water molecules upon passing from the adsorption phase into the solution, is found by the extrapolation of the isotherms of water desorption by molecules of several benzene derivatives. This energy ranges from 9.13 to 9.24 kJ/mol, thus corresponding to the energy of one H-bond, as measured by IR spectroscopy and NMR.     

荧光共振能量转移猝灭法测定片剂中莫西沙星含量

基于在pH 6.50的B-R缓冲溶液,十二烷基硫酸钠(SDS)介质中,吖啶橙(AO)-罗丹明B(RB)能够发生有效的能量转移,使RB荧光增强,而加入莫西沙星(MXFC)后使得RB的荧光猝灭,且其荧光淬灭程度与莫西沙星的质量浓度在1.00～10.0mg.L-1范围内呈线性关系,据此提出了利用AO-RB荧光共振能量转移,荧光淬灭法间接测定片剂中莫西沙星含量的方法。方法的检出限(3S/N)为0.039mg.L-1。方法用于莫西沙星片剂的分析,测定值与高效液相色谱法测定值相一致,加标平均回收率为99%,相对标准偏差(n=5)均小于0.9%。     

一种癌症早期检测的新方法——尿液的荧光光谱

比较了癌症患者尿液自体荧光光谱与健康人尿液自体荧光光谱的差异,提出了用荧光试剂与尿液中的某些组分反应生成新的发光体,用于癌症患者病情确诊的辅助手段;实验结果表明,直肠癌、鼻咽癌、结节状组织细胞淋巴瘤、肺癌及其它癌症的阳性率分别为71％、71％、67％、50％、61％,该法适于健康普查,将有利于癌症的早期发现,提高癌症的治愈率。     

一种确定反应中间态几何特征和能量的综合性方法

通过综合使用传统的过渡态优化算法、数学统计工具以及人工神经网络算法(ANN)找到一种不依赖于反应物起始构象而得到化学反应中过渡态结构和能量的方法. 在两个反应物互相接近的过程中, 每一步的几何构象都对应着一个系统能量值. 本研究的目的是尽可能地收集处在反应能量面上的这种能量点值. 通过采用几何参数作为自变量对势能面进行模拟研究, 得到了势能面上对应过渡态结构的一阶鞍点. 采用乙醛负离子和甲醛作为反应物, 对经典的醛醇缩合反应中的亲核进攻步骤进行了研究. 对内禀反应坐标(IRC)路径的计算是从反应物的三组不同起始构象出发, 最终获得了反应势能面上的96个点. 本研究中的势能面采用人工神经网络算法进行模拟研究, 并利用交叉验证方法评估得到的结果, 避免了采用人工神经网络算法时过度拟合情况的发生.     

A New Method to Remove Neutral Template in the Synthesis of HMS

The synthesis of mesoporous molecular sieves is believed to be one of the most exciting discoveries in the field of material science1. The formation of mesoporous structure relies on the template effect of the surfactant micelles2-4. Generally three kinds of interactions are involved in this process, i.e. electrostatic charge matching, hydrogen bonding and coordinative interaction5. After template-directed synthesis procedure, the after-treatment process is needed to remove the surfactant temp…     

荧光光度法直接测定环境水中苯酚和十二烷基苯磺酸钠的含量

本文研究了用荧光分光光度法直接测定环境水中苯酚和十二烷基苯磺酸钠（ＳＤＢＳ）二种水中污染物。在ｐＨ〉１１直接测定ＳＤＢＳ含量，波长为λｅｘ／λｅｍ＝２３０／２９５ｎｍ，检出限４．４ｎｇ／ｍＬ，线性范围０￣２．２μｇ／ｍｌ。在ｐＨ＝６，波长为λｅｘ／λｅｍ＝２３０／２９５ｎｍ，测得二者合量，从合量中减去ＳＤＢＳ含量即得苯酚含量，检出限４．０ｎｇ／ｍｌ，线性范围０￣０．８５μｇ／ｍＬ，回收率达９９％￣     

New Procedure for Determining the Solubility of Lypophilic Nonionic Surfactants in Water

The procedure that allows to study the kinetics of a dissolution of oleophilic nonionic surfactants in water and to determine the equilibrium values of solubility (S ^eq _w) was proposed, based on the spectrophotometry of extremely dilute, finely dispersed o/w emulsions of these substances prepared by sonication. The equilibrium values of solubility of tetraethoxylated p-nonylphenol (Neonol AF_9-4) and sorbitan monolaurate (Span-20) at 293 K in water are 3.67 × 10^–5 and 1.03 × 10^–5 M, respectively. For the tetraethoxylated p-nonylphenol, the equilibrium value of solubility in water determined by the proposed procedure agrees well with that determined by precision tensiometric measurements.     

苯羟基化为苯酚新型催化剂

首次介绍了一种以ＨＺＳＭ－５为载体，以Ｌａ２Ｏ３为促进剂，采用浸渍法制成的Ｆｅ２Ｏ３－Ｌａ２Ｏ３／ＨＺＳＭ－５新型催化剂，在常压，反应温度为３００℃条件下，以Ｈ２Ｏ２为氧化剂使苯羟基化为苯酚，取得了苯的最高转化率和苯酚的选择性分别达到４０．２％和９４．０％的结果。     

基于氧化碳球的上转换荧光传感新方法检测银离子

本文构建了以上转换纳米粒子(Upconversion Phosphors,UCPs)为供体,氧化碳球为受体的荧光共振能量转移新体系用于Ag+的检测.氧化碳球对上转换荧光供体的发射具有良好的猝灭效果,当氧化碳球的浓度达到0.038 mg/mL时,猝灭效率最大,达到78％.向该体系中加入Ag+后,在浓度为1～100 nmol/L范围内,UCPs的荧光恢复程度与Ag+的浓度呈线性关系.该方法测定Ag+的检出限为0.98 nmol/L.本实验首次尝试构建以氧化碳球为受体的荧光共振能量转移(FRET)传感器来检测Ag+,结合了UCPs的上转换发光特性和氧化碳球优良的猝灭能力以及良好的分散性,为Ag+的检测提供了一个新的方法.     

水中微量苯胺类化合物的重氮化耦合荧光猝灭法测定

基于亚硝酸根-苯胺类化合物-2-萘酚重氮化-耦合反应体系对2-萘酚的荧光猝灭作用,建立了荧光猝灭法检测水中微量苯胺类化合物的新方法.方法的激发波长为353 nm,发射波长为418 nm.在所选定的实验条件下,测定苯胺、对硝基苯胺、邻硝基苯胺的线性范围分别为:0～640 μg/L,0～720 μg/L和0～740 μg/L,检出限分别为0.017 9、0.020 5、0.026 5 mg/L.方法用于环境水样中的苯胺类化合物的测定,回收率为98%～103%.     

高灵敏分光光度法测定全血铁

为建立一种快速、简便、灵敏的分光光度法测定全血中微量铁,在非离子型表面活性剂聚氧乙烯月桂醚(Brij-3 5 )及聚氧乙烯异辛基苯基醚(TritonX -1 0 0 )存在下,用2 (5 硝基2 吡啶偶氮) 5 [N 正丙基 N (3 磺酸丙基)氨基]苯酚二钠(简称Nitro -PAPS)作显色剂直接光度法测定全血中微量铁。结果表明,该法在pH 4 0的乙酸乙酸钠缓冲液中,以5 90nm为测定波长,可直接测定全血中微量铁,本法线性范围为0～2 2 7μg/mL ,表观摩尔吸光系数为9 97×1 0 4L/(mol·cm) ,回收率为97 5 %～1 0 1 8%。结论:该法具有操作快速、简便、结果灵敏可靠等优点,适合临床医疗、预防保健等应用,值得推广。     

水溶性荧光共轭聚合物MPS-PPV的聚合新方法及其荧光波长调控的研究

在NaOH/C2H5OH/DMF溶液中,实现了水溶性阴离子荧光共轭聚合物聚-[5-甲氧基-2-(3-磺酰化丙氧基)-1,4-苯撑乙烯](MPS-PPV)单体的快速聚合并提高了聚合产率。通过改变溶液中NaOH的浓度,实现了对聚合物荧光发射波长的调控。对聚合物进行了元素分析、红外光谱以及分子量的表征,并探讨了不同聚合条件下得到的MPS-PPV的荧光和紫外光谱变化。研究了过氧化氢对MPS-PPV荧光的影响,为基于荧光聚合物的新型传感器的研制提供了新思路。     

3,5-diBr-DMPAP选择性光度法测定乳粉中微量铁

建立了一种在表面活性剂TritonX -1 0 0存在下 ,用 2 -(3 ,5 -二溴 -2 -吡啶偶氮 ) -5 -二甲氨基酚 (简称 3 ,5 -diBr-DMPAP)作显色剂选择性测定乳粉中微量铁的新方法。结果表明 ,在pH 4 0的乙酸 -乙酸钠缓冲液中 ,以 746nm为测定波长 ,可选择性测定乳粉中微量铁 ,本法线性范围为 0～ 1 2 5 μg· (1 0mL) - 1,表观摩尔吸光系数为 2 83× 1 0 4 L·mol- 1·cm- 1,回收率为 98 1 %～ 1 0 2 4% ,批内和批间变异系数 (CV)分别为 2 5 %与 3 1 %。该法具有操作快速、简便、结果灵敏可靠等优点。     

Large-Volume Direct Injection for Determining Naphthalene Derivative Pesticides in Water Using a Restricted-Access Medium Column in RPLC-LC with Fluorescence Detection

A simple multidimensional system for direct injection of large volumes has been developed for the determination of three naphthalene-derivative pesticides [2-(1-naphthyl) acetamide (NAD), 1-naphthyl methylcarbamate (carbaryl) and 1-naphthol] in water using fluorescence detection. The capability of restricted-access medium (RAM), pre-columns for eliminating large interfering molecules, combined with an optimised, coupled-column separation procedure, large volume injection (LVI) and fluorescence detection, gave excellent sensitivity for target analytes. The maximum admissible concentration levels established by the European Union (EU) for individual pesticides and their related compounds in drinking water (0.1 μg L^?1) were easily reached. Detection limits were lower than, or equal to, 0.003 μg L^?1. Average recoveries ranged: 81–104% (n=3) with relative standard deviation (RSD) values: 2–7%. Application of the coupled-column liquid chromatography (LC-LC) method was by determining target analytes in ground water samples from five agricultural zones of Almería, (Spain) over three months.     

分散固相微萃取法测定水样中甲基紫的含量

建立了一种磁分散固相微萃取分光光度法检测水样中甲基紫含量的分析方法,主要考察了样品的p H值、吸附剂的用量、萃取与解析时间、解析剂的种类、解析剂用量以及离子强度对甲基紫萃取性能的影响。最优化条件下,线性关系在0.01~0.2?g/m L的范围内良好,线性相关系数也较高(R20.99)。经检测,日内重复性5.3%,日间重复性4.9%。检出限为0.024?g/m L,定量限为0.079?g/m L。还研究了在湖水和鱼塘水中不同加标量的回收率,其中湖水的加标回收率在94.3%~101.0%,鱼塘水的加标回收率在85.4%~90.0%。