基于碳纳米管修饰电极的甲醛生物传感器

利用甲醛脱氢酶和羧基化多壁碳纳米管修饰的丝网印刷电极,制备了基于还原型辅酶Ⅰ检测的甲醛生物传感器,并优化了传感器的检测条件.结果表明,此传感器对甲醛有较好的电催化氧化作用,显著降低了甲醛的氧化峰电位.在0.001～11nmol/L范围内,响应电流与甲醛的浓度线性相关,其线性回归方程为z(μA)=0.944c(mmol/L,) +0.0623,相关系数为0.9934,响应时间约为20 s,检出限为0.2 μmol/L( S/ N=3).     

银离子交换的沸石修饰电极的循环伏安新特性

银离子交换沸石Y修饰电极(Ag⁺-沸石Y)的循环伏安(CV)行为, 不同于溶液中的银离子在固体银电极表面上的CV行为. Ag⁺-沸石电极中银离子还原电位明显受沸石体内银簇影响. 依据Ag⁺-沸石修饰电极在含有能够与银离子形成难溶盐的电解质中的CV行为, 本文发现了沸石对溶液中阴离子具有尺寸选择效应, 并解释了银离子交换沸石修饰电极的循环伏安反应特性.     

电聚合β-环糊精修饰电极的制备及其对铜离子的检测

采用循环伏安法(CV),由β-环糊精(β-CD)单体在玻碳电极(GCE)表面电聚合制得聚β-CD膜修饰电极(β-CD/GCE)。实验表明,β-CD/GCE对Cu2+具有明显的电催化作用,在pH=5.85的磷酸盐缓冲溶液(PBS)中,Cu2+浓度与其峰电流在4.01×10-4～1.05×10-7 mol·L-1范围内呈良好的线性关系,线性方程为:ip=-1.975c-1.336×10-4(i:A,c:mol·L-1),相关系数R=0.9981,检出限(S/N=3)为5.03×10-8mol·L-1。方法应用于实际样品测定,回收率在98.0%～103%之间。     

Syntheses,Crystal Structures and Theoretical Studies of Three Novel Salts of Vortioxetine and the Investigation of Their Solubility

Three new vortioxexine(VOT) salts with salicylic acid(SA), 5-fluorouracil(FU) and(p-nitrophenyl)-acetic acid(PA) have been synthesized and characterized in detail. In VOT-SA(1:1), the protonated VOT and deprotonated salicylic anion form a tetrameric unit with the R4 4(12) synthon via N(1)–H(1)···O(1)a(a: x–1, y, z) and N(1)–H(2)···O(2)b(b: –x, –y, –z+1) hydrogen bonds. However, in VOT–FU(1:2), the protonated VOT and deprotonated 5-fluorouracil anion feature an R4 4(16) ring motif via N(1)–H(1)···O(2)c(c: –x+1, –y+1, –z+1) and N(1)– H(2)···O(1)d(d: x, y–1, z) hydrogen bonds. The neutral FU extends the R4 4(16) ring to form a two-dimensional structure through R2 2(8) N–H···O and N(6)–H(4)···N(4)e(e: –x+1, y–1/2, –z+1/2) hydrogen bonds. In VOT-PA(1:1), PA molecules are linked through N(1)–H(1)···O(1)f(f: –x+1, y+1/2, –z+1) and N(1)–H(2)···O(2), which forms a right-handed helical structure. Furthermore, components of the crystalline phase have also been investigated in terms of their corresponding Hirshfeld surface, and the salification improves the equilibrium solubilities and dissolution rates of VOT in three salts at 25 ℃ in water.     

STRUCTURE OF DIAQUO（N—p—METHYLPHENYL）IMINODIAC—ETATO COPPER（Ⅱ）

<正> Diaquo (N - p-methylphenyl) iminodiacetato Copper (Ⅱ) Cu-CH3C6H4N(CH2COO)2](H2O)2, Mr = 320. 79, orthorhombic,Pcab (No. 62 non-stamdard setting, symmetry code: x,y,z; 1/2 + x ,y , 1/2 + z; x; , 1/2 -y , 1/2 -z; y,z),a = 7. 612(2), b = 12.938(1), c=26.574(3)(?) , V = 2616. 9(2) A3, Z = 8, Dc=1. 628 Mg.m-3, Do = 1.63 Mg.m-3, μ(CuKα) = 2. 62mm-1, F(000) = 1320, T =298K, final R = 0. 049 for 1136 observed reflections. In the molecule, the Cu (1) atom is bonded to two carboxyl oxygen atoms O(1), O(2), and two oxygen atoms O(10), O(20) from two water molecules and an imino N(1) atom to form a distorted square pyramid, in which the O(20) atom occupies an axial position and bond length of Cu(1)- O(20) 2.315(?) shows Jahn-Teller effect.     

块状碳/氧化镍复合物的合成及电容特征

应用离子交换法将N i2+离子引入酚醛凝胶并碳化,制备出块状的碳/氧化镍(C/N iO)复合物材料.原子吸收光谱(AAS)、X射线衍射(XRD)和循环伏安测试(CV)表明,样品中引入的N i含量可以达到5.9%(by m ass),其存在形式主要是N iO,伴有少量未被氧化的金属N i,比电容和电容性能以N i含量为4.4%的表现最佳.     

Syntheses and Structures of Rare Earth Nitrate Complexes with 2.6-Diacetylpyridinebis(Semicarbazone)

Six rare earth nitrate complexes of 2, 6-diacetylpyridinebis (semicarbazone) (DAPSC) were synthesized and characterized by elemental analysis, IR spectra and electrical conductance. Molecular and crystal structures of complex [Sm(DAPSC)(NO3)2(EtOH)]NO3 were determined by X-ray diffraction method. C13H21N10O12 Sm crystallized in the monoclinic apace group C2/c with the following unit-cell constants, a=16.674(2)A, b = 10. 715(2)A, c = 25.242(4)A . β = 100.077(11)°; z=8, the final R factor is 0.025. The coordination number of Sm3+ is ten.     

长链氨羧络合剂萃取稀土饵

研究了长链氨羧络合剂N,N′-二(十二烷基)乙二胺二乙酸钠(Na2R2Y)的氯仿溶液萃取稀土饵的行为;考察了溶液酸度、络合剂浓度、相比和温度对萃取率的影响.用摩尔比法测定了Na2R2Y与Er3+的络合摩尔比为1∶1;结果表明,Na2R2Y的氯仿溶液对饵的萃取率随络合剂浓度的增大而增大,随温度的升高而降低.     

铁氰化锰修饰玻碳电极的制备及其电化学行为

采用循环伏安法成功制备了铁氰化锰 (MnHCF)膜修饰玻碳 (GC)电极。探讨了影响膜电沉积的各种因素 ,通过扫描电位范围对膜电沉积的影响 ,确定MnHCF膜的组成为Mn3 + Fe3 + (CN) 6[普鲁士黄类似物Fe3 + Fe3 + (CN) 6]。首次发现在整个膜电沉积过程中存在 3个阶段 ,最后阶段对制备均匀、致密的MnHCF/GC电极至关重要。阴离子的种类对MnHCF/GC电极的伏安特性及电催化活性有显著的影响 ,只有当支持电解质中含有HPO2 -4离子时 ,MnHCF膜修饰电极对H2 O2 的电氧化才表现出良好的电催化作用。在 0 .10mol/LNa2 HPO4溶液中 ,催化电流Δipa与过氧化氢浓度 (CH2 O2 )的线性关系为 :Δipa(μA) =2 .84 32 +2 .2 2 89× 10 4CH2 O2 (mol/L) (R =0 .994 4 ,n =9) ;线性范围为 1.4× 10 -5～ 1.8× 10 -3 mol/L ;检出限为 3.6× 10 -6mol/L (S/k =3)。     

R_3GeVO_9(R=Y,La)∶Eu~(3+)(或Dy~(3+))的合成及其发光性质

采用高温固相法合成了稀土复合钒锗酸盐R3GeVO9(R =Y ,La)体系 ,并以此为基质研究了Eu3+和Dy3+在其中的发光性质 ,以Eu3+为结构探针探讨了Eu3+在R3GeVO9(R =Y ,La)中的格位情况。同时 ,还研究了被取代离子R3+的Z/r对Eu3+的红橙比和Dy3+的黄蓝比的影响以及浓度、温度和Bi3+对它们发光强度的影响。     

对硫磷在纳米氧化铝薄膜修饰电极上的电化学行为及其测定

制备了纳米氧化铝修饰玻碳电极(nano-Al2O3/GCE/CME),用循环伏安法(CV)、线性扫描伏安法(LSV)研究了对硫磷(TP)在nano-Al2O3/GCE/CME上的电化学行为.实验表明,该修饰电极与裸电极相比能显著提高TP的氧化还原峰电流并降低其氧化峰电位.在0.1 mol/L HAc-NaAc缓冲溶液(pH =5)中,TP在该修饰电极上产生1个不可逆的还原峰( Epc1=-0.567 V)和1对可逆氧化还原峰( Epa2=0.018 V和Epc2=-0.008 V) ,氧化峰电流与TP的浓度在2.5×10-9～1.0×10-7 mol/L和1.0×10-7～1.0×10-5 mol/L范围内具有良好的线性关系,回归方程分别为: ip(μA)=0.2529+4.201C(μmol/L), r=0.9984和ip(μA)=0.6752+0.3181C(μmol/L), r=0.9946.开路富集30 s后,检出限为1.0 ×10-9 mol/L(S/N=3).在1.0×10-5 mol/L TP试液中连续测定10次,其RSD为3.8%.用此方法测定了蔬菜中TP的含量,回收率为95. 6%～100.5% ,结果满意.     

离子缔合型离子选择电极的研究 I: PVC膜铬(VI)离子选择电极的研制的和应用

A new Cr(VI)-selective electrode of PVC membrane based on triheptyl dodecyl ammonium iodide is described. The response of the electrode is Nernstian for Cr(VI) concentration down to 2X10-6M in 0.03-0.13N HF solution. Limit of detection is 5X10-7M. The plot of logarithms of selectivity coefficients vs. z/γ of various anions is essentially linear with a correlation coefficient of -- 0.88. Applications of the electrode in determination of total Cr in steels and copper alloys, and Cr(VI) in waste-water from chromium electroplating are reported.     

电喷雾电离-串联质谱法测定纺织皮革产品中4,4-二氨基二苯醚

在不需要色谱分离的前提下,应用电喷雾电离-串联质谱法(ESI-MS/MS)对纺织品中偶氮染料还原产物4,4′-二氨基二苯醚进行测定。在MS/MS中,选择电喷雾离子源,以正离子扫描,选择离子监测模式和二级选择反应监测模式对4,4′-二氨基二苯醚进行定性和定量检测。以[M+H](m/z201)为母离子,选择其二级离子中碎片离子[M+H-NH3](m/z184)和[M+H-C6H7N](m/z108)为子离子。方法的检出限(19S/N)为70 ng.L-1。以1 ng.L-14,4′-二氨基二苯醚溶液进样2μL,平行测定9次,峰面积测定值的相对标准偏差为1.7%。     

肾上腺素在预阳极化碳糊电极上的电化学行为研究

建立了预阳极化碳糊电极(PACPE)测定肾上腺素(EP)的新方法。实验表明,EP在PACPE上有很好的电化学响应,在pH 7.00的PBS缓冲溶液中,EP的氧化峰电流最大,且与其浓度在2.0×10-7~1.0×10-4mol/L范围内呈良好的线性关系,线性方程为:Ip(μA)=0.4598+0.1544c(μmol/L),相关系数R=0.9981,检出限为2.9×10-8mol/L。方法可用于注射液中EP含量的测定。     

高效液相色谱固相萃取法测定血浆及大肠癌细胞中5-Fu的含量

采用高效液相固相萃取提取和分析大肠癌细胞SW480-B7和SW480-NC及血浆中5-Fu的含量,提高了萃取效率。优化色谱条件,在流动相中添加三氟乙酸改善了峰型,提高了理论塔板数。色谱柱:Diamonsil C18柱(5μm,4.6×250 mm),流动相:0.08%磷酸水溶液(含0.15%三氟乙酸)-甲醇溶液(体积比95:5),检测波长266 nm。血浆样本线性范围0.025~25μg/m L,检出限0.02μg/m L(S/N≥3),回归方程为Y=34783X+34562(R~2=0.9991);癌细胞线性范围0.03125~12.5μg/m L,最小检测浓度0.025μg/m L(S/N≥3),回归方程为Y=37963X+36842(R2=0.9993)(SW480-B7);Y=30244X+32421(R2=0.9998)(SW480-NC);所有样品回收率在86%~102%之间,日内RSD和日间RSD分别小于5%和8%。     

铬黑T流动注射法在线测定水样中的微量Ni(Ⅱ)

利用铬黑T(EBT)与镍(Ⅱ)发生显色反应,生成一种紫罗兰色的配合物,建立了新的在线分析镍的流动注射法。在pH为10的H2B4O7-KCl-NaOH缓冲溶液中,铬黑T用量2.5 mL,缓冲液用量2.5 mL,灵敏度最好。方法的线性范围为10～1000μg·L-1,在10～100μg·L-1浓度范围内,ΔA=0.4234C+3.4336,R2=0.9998;在100～1000μg·L-1浓度范围内,ΔA=0.3907C+12.869,R2=0.9985,线性关系良好。检出限(3S/N)为3.4μg·L-1,加标回收率在98.8%～104.2%之间,相对标准偏差(n=14)为1.82%(200μg·L-1的镍标液),结果令人满意。     

近期热点文章

High-Performance Rh2P Electrocatalyst for Efficient Water Splitting H. Duan, D. Li, Y. Tang, Y. He, S. Ji, R. Wang, H. Lv, P. P. Lopes, A. P. Paulikas, H. Li, S. X. Mao, C. Wang, N. M. Markovic, J. Li, V. R. Stamenkovic, Y. Li J. Am. Chem. Soc. DOI: 10.1021/jacs.7b01376 通过溶剂热方法合成Ru2P/C催化剂,P组分在表面富集,对氢析出反应（HER）与氧析出反应（OER）具有优异的催化活性.     

Hydrothermal synthesis, structure and property of nano-BaTiO_3based dielectric materials

A series of Ba1-xSrxTi1-yZryO3 (0≤x≤0.5, 0≤y≤0.4) and Ba1-xZnxTi1-ySnyO3 (0≤x≤0.3, 0≤y≤0.3) solid solutions were synthesized by low-temperature/low-pressure hydrothermal method below 170℃, 0.8 MPa. XRD pattern and cell parameters-composition figures of these prepared powders demonstrated that they are completely miscible solid solutions based on BaTiO3. Furthermore, TEM showed that they have a shape of uniform, substantially spherical particles with an average particle size of 70 nm in diameter. The sintered ceramics of those powders doped by Sr2+ and Zr4+ or Zn2+ and Sn4+ have dielectric constant twelve times higher than and dielectric loss 1/6 those of pure BaTiO3 phase at room temperature.     

TATP的质子转移反应的质谱研究

利用密度泛函理论(DFT), 在B3LYP/cc-pVDZ水平上, 对三过氧化三丙酮(Triacetone triperoxide, TATP)及其质子化离子[TATP+H]+进行了构型优化和质子亲和势(Proton Affinity, PA)计算, 研究结果表明, PA(TATP)=866.73 kJ/mol大于PA(H2O)=691.0 kJ/mol, TATP与H3O+可发生质子转移反应. 在自行研制的质子转移反应质谱(Proton transfer reaction mass spectrometry, PTR-MS) 装置上, 研究了TATP与H3O+反应生成的特征离子. 当漂移管中E/N=1.4×10-15 V·cm2时, 在荷质比m/z=91, 75, 74, 59, 43等处观察到了产物离子. 降低E/N至0.5×10-15 V·cm2后, 在m/z=223处观察到了质子化产物离子([TATP+H]+), 验证了计算结果; 结合[TATP+H]+的构型, 分析了TATP质子转移反应产物离子可能的归属及其形成过程. 结合PTR-MS漂移管内E/N的改变引起m/z=223, 91, 43等离子的变化特征, 可实现TATP的准确识别和快速定量检测, 检测下限达到5.0×10-10 mol/L(±50%).     

Synthesis and Crystal Structure of Complex [Pb(qina)2(DMSO)]·H2O

A novel complex [Pb(qina)2(DMSO)]·H2O was synthesized, of which qina- is the quinaldic acid radical and DMSO the dimethyl sulfoxide. Elemental analysis, IR spectra, and X-ray single-crystal diffraction were carried out to determine the composition and crystal structure. This complex belongs to monoclinic system, space group P121/n1, with a = 7.1553(17), b = 17.543(2), c = 17.306(2)(A),β = 91.671(4)°, C22H20N2O6PbS, Mr = 647.65, Z = 4, V= 2171.5(6)(A)3, Dc= 1.981g/cm3,μ = 7.908 mm-1, F(000) = 1248, -9≤h≤6, -23≤k≤ 19, -22≤l≤22, R= 0.0221 and wR =0.0488. Weak coordinate bond is formed between oxygen atom in DMSO and Pb(Ⅱ ). There are also weak interactions, such as π-π interaction, hydrogen bonds and so on, among the complex molecules.