Flow Injection Analysis of Hydrazine in the Aqueous Streams of Purex Process by Liquid Chromatography System Coupled with UV-Visible Detector

Present study describes the development of a rapid, sensitive and selective flow injection analysis of hydrazine in the aqueous streams of purex process by liquid chromatography system coupled with UV-Visible detector. The method is based on the formation of yellow coloured azine complex by reaction of hydrazine with para-dimethy laminobenzaldehyde (pDMAB). The formed yellow coloured complex is stable in acidic medium and has a maximum absorption at 460 nm. The presence of uranium in hydrazine solution is not interfering in the analysis. Under optimum condition, the absorption intensity linearly increased with the concentration of hydrazine in the range from 0.05-10 mg?L–1 with a correlation coefficient of R2=0.9999 (n=7). The experimental detection limit is 0.05mgL–1. The sampling frequency is 15 samples h–1 and the relative standard deviation was 2.1% for 0.05 mg?L–1. This method is suitable for automatic and continuous analysis and successfully applied to determine the concentration of hydrazine in the aqueous stream of nuclear fuel reprocessing.

稀土与丙氨酸、咪唑三元配合物的FTIR和UV/VIS光谱

用氯化稀土 (La ,Pr ,Eu)与α 丙氨酸、咪唑固体混配体配合物以及对应稀土盐、配体α 氨基酸和咪唑进行了FTIR光谱和固体UV/VIS、水溶液UV/VIS光谱测试 ,分析了配合物的光谱特性 ,讨论了配体和Ln(Ⅲ )

固定波长UV-VIS光对大豆油品质的影响

通过设定不同温度、光强度、光波长、时间对大豆油进行脱色试验,对大豆油的过氧化值、酸价及色泽进行了测定,研究分析了大豆油过氧化值、酸价及色泽随温度、光强度、光波长及照射时间变化的基本规律。通过单因素及正交试验,VIS-450光照脱色的最优工艺条件:光通量2 400 lm,温度35℃,时间3 h,脱色率为53.2%。UV-365光照脱色的最优工艺条件:光通量2 400 lm,温度35℃,时间2 h,脱色率为42.4%。结果表明:UV-365比VIS-450对大豆油品质劣变影响较大;VIS-450比UV-365对大豆油脱色率影响较大。

磺酸基对掺杂酞菁在溶胶-凝胶复合体系中UV/Vis吸收光谱的影响

选择、设计具有代表性无取代酞菁镍(NiPc)和周环带有4个磺酸基的四磺化酞菁镍(NiTSPc),采用溶胶-凝胶湿化学将其均匀掺入SiO2凝胶基质,制备无机基质酞菁掺杂复合光功能材料并考察磺酸基的引入对掺杂酞菁在溶胶-凝胶复合体系中UV/Vis吸收光谱的影响。研究结果表明水溶性磺酸基的引入有助于改善酞菁的溶解性,进而实现其与溶胶-凝胶体系的稳定互溶,使酞菁均匀掺杂复合材料的制备成为可能。

UV/Vis光谱法研究红子色素的稳定性

本文报导从红子提取、分离天然色素及酸碱和温度等对该色素稳定性的影响。

UV-VIS分光光度法在环境监测上的应用及测定方法的选择

近三年来,国家环境保护部修订或更新了许多用UV-VIS(紫外-可见)分光光度法测定环境指标的标准方法。就UV-VIS分光光度法在环境监测领域中的应用进行分类阐述,并对环境指标的测定方法选择进行分析。

竹活性炭负载催化剂UV/VIS光降解甲醛的研究(摘要)

利用竹活性炭（BAC）的强吸附性和二氧化钛（TiO2）的光催化氧化性二者的协同作用,对水溶液中的甲醛进行处理。在综述国内外研究的基础上,采用溶胶-凝胶法制备TiO2溶胶,采用浸渍法将TiO2负载于竹活性炭的表面,研制了一种以竹活性炭为基质负载TiO2的复合紫外光催化剂（TiO2/BAC）,同时制备了铂、氮共掺杂的可见光响应型催化剂（Pt/N/TiO2/BAC）,并考察二者对水溶液中甲醛的光催化处理效果。1）BAC以及TiO2/BAC的制备以竹子为原料,通过磷酸活化法制备不同孔径和比表面积的系列BAC作为载体。

DFT Investigations(Geometry Optimization, UV/Vis, FT-IR, NMR, HOMO-LUMO, FMO, MEP, NBO, Excited States) and the Syntheses of New Pyrimidine Dyes

In the present work, the molecular structures of two new synthesized dyes：（4,6-dimethylpyrimidin-2-ylamino）（5-p-tolylisoxazol-3-yl）methanol（PS-1） and N-（4,6-dimethylpyrimidin-2-yl）-5-phenylisoxazole-3-carboxamide（PS-2）, have been investigated using density functional theory（DFT） in dimethylformamide（DMF） for the first time. The electronic spectra of new dyes in a DMF solvent were carried out by time dependent density functional theory（TD-DFT） method. After quantum-chemical calculations two new dyes for the optoelectronic applications were synthesized. FT-IR spectra of the title compounds are recorded and discussed. NucleusIndependent Chemical Shifts（NICS） calculations have also been carried out for the title compounds. The computed absorption spectral data of the title compounds are in good agreement with the experimental data, thus allowing an assignment of the UV spectra. The HOMO and LUMO molecular orbitals, excitation energies and oscillator strengths for the dyes have also been calculated and presented.

Interaction of Ca^(2+) and soil humic acid characterized by a joint experimental platform of potentiometric titration, UV–visible spectroscopy, and fluorescence spectroscopy

Rocky desertification has become a major environmental issue in the karst region of southwestern China.Karst rocky desertification was more severe in regions of limestone soil than in adjacent regions of other soils,despite the relatively higher soil organic matter(SOM)content in limestone soil.The underlying mechanism remains ambiguous.We speculated that the geochemical characteristics of limestone soils in the karst region plays an essential role,especially the high calcium content of limestone soil.To test this hypothesis,we collected limestone soil samples from a limestone soil profile in the southwestern China karst region and extracted humic acid(HA)from these limestone soil samples.We investigated the interaction of Ca^(2+)and three HA samples on a joint experimental platform,which consists of an automatic potentiometric titrator,a UV–visible spectrometer,and a Fluorescence spectrometer.HA solutions were titrated by Ca^(2+)and optical spectra of the HA solutions were monitored during the titration experiments.The results indicated that:(1)the interaction of Ca^(2+)and HA is a combined process of adsorption and complexation.Adsorption dominated the overall distribution behavior of Ca^(2+),which could be fit by Langmuir and Freundlich isotherm models.Complexation was distinguished only when the concentration of Ca2+is low;(2)the changes of UV–visible spectroscopy and excitation–emission matrix fluorescencespectroscopy spectra of HA samples when they were binding with Ca^(2+)implied the apparent molecular size and structure of HA became larger and more complex;(3)the combination of Ca^(2+)and HA plays an important role in the SOM preservation of limestone soils but the stability of the Ca–HA association was relatively weak.The present study draws attention to maintaining the relatively higher Ca^(2+)concentration in limestone soils in ecologic restoration attempts in karst regions.

Synthesis, Crystal Structure, Thermal Stability and Solid UV-Vis Absorption Spectra of One New Copper(Ⅱ) Coordination Polymer

A new coordination polymer [Cu2(OH)(nbta)(tib)(H2 O)2]n(1, H3 nbta = 5-nitro-1,2,3-benzenetricarboxylic acid, tib = 1-(4 H-1,2,4-triazol-4-yl)-4-(imidazol-1-yl)benzene) constructed from dimeric Cu(Ⅱ) units has been synthesized under hydrothermal conditions and structurally characterized by single-crystal X-ray diffraction analysis. The compound crystallizes in monoclinic system, space group I2/c, with a = 17.8474(9), b = 11.7588(6), c = 21.9221(11) ?, β = 104.419(5)°, V = 4455.7(4) ?3 and Z = 8. Compound 1 is a three-dimensional structure constructed from dimeric Cu(Ⅱ) units and presents a 2-nodal(3,5)-connected net. Moreover, the thermal stability and solid UV-Vis absorption spectra have been investigated.

TiO_2 Thin Film UV Detectors Deposited by DC Reactive Magnetron Sputtering

Crystalline TiO2 thin films were prepared by DC reactive magnetron sputtering on indium-tin oxide（ITO） thin film deposited on quartz substrate, the photoconductive UV detector on TiO2 thin films was based on a sandwich structure of C/ TiO2/ITO. The measurement of the I-V characteristics for these devices shows good ohmic contact. The photoresponse of TiO2 thin films was analyzed at different bias voltage. The detector shows a good photoresponse with a rise time of 2 s and a fall time of 40 s, the photocurrent is linearly increased with the bias voltage.

UV- VIS SPECTRA OF POLYANILINE DOPED WITH CAMPHOR SULFONIC ACID IN DIFFERENT ORGANIC SOLVENTS

The doping reaction of polyaniline with camphor sulfonic acid (CSAH) in different organic solvents was studied by UV Vis spectroscopy. The experimental results show that the polaron band of the species was shifted to shorter wavelength when polyaniline was doped with CSAH in N methyl 2 pyrrolidione (NMP) solvent, while the red shift of polaron band was observed when it was in N, N dimethylformamide (DMF). It indicates that the influence of different processing solvents on the doping property of polyaniline is greatly different. N methyl 2 pyrrolidione is a good solvent for polyaniline, polyaniline chain is unfolded in it. The interaction of NMP with CSAH is so strong that the resulting product is apt to dedoping, while the solubility of polyaniline in DMF is relatively low and polyaniline chain is in partly folded state. Thus the doping reaction is kinetically disadvantageous but thermodynamically advantageous.

IN SITU FTIR AND UV／VIS STUDY OF THE ADSORPTION OF CYTOCHROME C ON GOLO ELECTRODE

The adsorption behaviour has been studied using in situ FTIR and UV/Vis spectroscopy,voltammetry,AC impedance and polential step methods.The results show that cytochrome c can be irreversibly adsorbed on the gold surface in a complete monolayer and the adsorbed layer can mediate the redox reaction of cytochrome c in the solotiorr but not ail adsorbed cytochrome c molecules would play this role.

Optimization, Spectroscopic(FT-IR, Excited States, UV/Vis) Studies, FMO, ELF, LOL, QTAIM and NBO Analyses and Electronic Properties of Two New Pyrimidine Derivatives

In the given research,the molecular structures of two new compounds,4-((E)-3-(dimethylamino)styryl)-6-((E)-4-(dimethylamino)styryl)pyrimidine-2-amine(PM-1)and N-(4-((E)-3-(dimethylamino)styryl)-6-((E)-4-(dimethylamino)styryl)pyrimidine-2-yl)-4,6-dichloro 1,3,5-1,3,5-triazin-2-amine(PM-2),have been studied with the use of density functional theory(DFT/B3LYP/MidiX)in dimethylformamide(DMF)for the first time.The electronic spectra of the new compounds in a DMF solvent were carried out by temporally dependent density functional theory(TD-DFT)method.The computed absorption spectral data of the title compounds are in good agreement with the experimental data,thus allowing an assignment of the UV/Vis spectra.The equilibrium geometry,the HOMO and LUMO molecular orbitals,excitation energies,oscillator strengths and Natural Bond Orbital(NBO)analysis for the molecules have also been calculated and presented.FT-IR spectra of the title molecules are recorded and discussed.The electron location function(ELF),localized orbital locator(LOL)and quantum theory of atoms in molecules(QTAIM)analyses were also carried out.On the basis of polyvinyl alcohol(PVA)and synthesized molecules,polarizer for UV/Vis region of the spectrum has been developed.

The UV-VIS Studies of C_(60) Chemically Modified Polystyrene Film

The opticai properties of C,, chemicaiiy modified poiystyrene(C,, -PS copolymer) and the parent polystyrene (PS) films have been investigated.Addition of bulky C,, moiety, a special functional group, to the polystyrene by anovel organometallic reaction modified considerably the optical property of theparent polystyrene. The lattice periodicity of pure PS film is subject to someperturbation or distortion in varying degrees due to the covalent attachInent of bulkyC,, moiety to the polymer backbone. C,,-PS copolymer possesses a new energy ba-ndstructure with indirect forbidden band when compared with the parent PS.

探秘现代聚合物 应用UV／VIS光谱分析现代塑料领域中的聚合物

现代聚合物的品类日益增多，其性能也越来越多地依靠化学分析技术进行研究。除了众多常规费时费力的检测方法（如气相色谱法、液相色谱法）之外．新的UVNIS（NIR）光谱检测分析技术也得到了日益广泛的应用。

HPLC-ELSD-UV法同时测定人体胆结石中胆固醇、胆红素及各种胆酸的含量

目的:建立了人体胆结石中胆固醇、胆红素及各种胆酸的HPLC-ELSD-UV含量测定方法。方法:采用ZORBAX SB-C18(4.6mm×150 mm,5μg)色谱柱,0.1%醋酸溶液(A相)和甲醇(B相)为流动相梯度洗脱,流速:1.6 mL·min-1,紫外检测器(检测波长450 nm)和蒸发光散射检测器联用检测,柱温为室温。结果:测定了16个人体胆结石中胆固醇、胆红素及各种胆酸的含量。胆固醇在0.2204-1.653 mg·mL-1、胆红素在0.536-21.44μg·mL-1、各种胆酸在0.2-1.5 mg·mL-1范围内呈良好的线性关系;平均回收率分别为99.8%,101.5%,96.5%-101.2%,RSD分别为1.86%、1.71%、0.53%-2.14%(n=9);人体胆结石中的胆固醇、胆红素含量大多在776.3-972.5μg·mg-1和0.639-2.981μg·mg-1,各种胆酸未检出。结论:本法操作简便、快速、准确、适用范围广,可用于对人体胆结石中胆固醇、胆红素及各种胆酸的同时测定。

HPLC-UV法检测微生物降解体系中西维因含量

采用高效液相色谱-紫外检测（HPLC-UV）法测定微生物降解体系中西维因含量。根据细菌和霉菌降解体系的不同性质选用适宜前处理方式,以Sepax GP-C_（18）柱（150 mm×4.6 mm,5.0μm）为色谱柱,V（乙腈）∶V（水）=（56∶44）为流动相,流速0.5 m L/min,用紫外检测器于220 nm处检测西维因。结果表明,西维因标准品保留时间为7.922 min,在0.5~100 mg/L范围内线性关系良好,相关系数0.999 1。细菌培养液中西维因平均回收率为102.01%,RSD为0.29%;霉菌培养液中平均回收率为100.76%,RSD为1.22%;最低检测限为0.4mg/L。运用该法测得实验室保藏的细菌菌株A4和B-1在LB培养基中培养2 d对20 mg/L西维因降解率分别为35.72%、38.97%;霉菌菌株M-4和YAT在MM培养基中培养7 d对20 mg/L西维因降解率分别为38.69%、51.40%。该法简单,快速,回收率和精密度高,稳定性好。

A DFT and TD-DFT study on electronic structures and UV-spectra properties of octaethyl-porphyrin with different central metals(Ni, V, Cu, Co)

In this work,the octaethyl-porphyrins with different central metals(M-OEP,M=Ni,VO,Cu,Co)were used to investigate the ground-state molecular structure,electron distribution and UV-spectra properties on molecular level by density functional theory(DFT).The results showed that the calculation structure parameters of metalloporphyrins agreed well with the experimental value.According to the Natural Bond Orbital(NBO)analysis,the charge distribution of different metalloporphyrins was found that the charge values of the central metal M decreased with the order of VO<Ni<Co<Cu,while the bonding strength between M and the coordinating atom N was VO>Ni>Co>Cu.At the same time,the frontier molecular orbital calculations showed that the SOMO energy of VO(OEP)molecules in the open-shell system was higher than that of Co(OEP)and Cu(OEP),which means that its UV absorption characteristic peak would be red-shifted.In addition,the IEFPCM model of Time-dependent Density functional theory(TD-DFT)was further utilized to simulate the four substance in toluene solution:Co(OEP),Ni(OEP),Cu(OEP)and VO(OEP),and the Soret band peaks were calculated respectively as:382 nm,383 nm,391 nm and 401 nm.Furthermore,the quantitative simulation analysis of metalloporphyrins was combined with experimental data.It could be found that the location rules of the four kinds of metalloporphyrins calculated absorption characteristic peaks were consistent with the experimental ones,and the relative errors of each peak were within 3%.These methods used above provide a theoretical path for analyzing and identifying unknown porphyrin compounds in petroleum.