ZnONPs增敏流动注射化学发光法检测雨水中的H2O2

基于ZnO纳米颗粒(ZnO nanoparticles,ZnO NPs)增敏luminol-H_2O_2化学发光,结合流动注射技术,研究建立一种简单、快速、灵敏地测定雨水中微量H_2O_2的方法。考察pH,ZnO NPs、luminol和H_2O_2浓度对化学发光的影响。在优化条件下,H_2O_2浓度在0.06~20μmol/L范围内,H_2O_2浓度的对数(lg c)和化学发光峰面积的对数(lg A)具有良好的线性关系,检出限(LOD)为0.016μmol/L(3σ)。将此方法应用于雨水中微量H_2O_2的测定,回收率为95%~102%,RSD(n=11)为2.41%。     

高锰酸钾—鲁米诺化学发光体系测定香草醛

为了拓展流动注射化学发光法在食品检测中的应用,利用草醛能够增敏NaOH介质中高锰酸钾—鲁米诺化学发光体系的发光信号的特点,建立了化学发光测定香草醛的方法。文中考察了介质浓度、发光试剂浓度等因素对发光体系信号的影响,确定了测定香草醛的最佳条件:介质NaOH浓度为0.20 mol/L,高锰酸钾浓度为3.0×10-5mol/L,鲁米诺浓度为7.0×10-5mol/L。在优化实验条件下,体系的发光强度与香草醛浓度在5.0×10-8～3.0×10-6 g/mL内呈线性关系,标准曲线:ΔI=7.188 3×108C(g/mL)+71.767 4(r=0.994 2)。对5.0×10-7g/mL的香草醛平行测定11次,相对偏差为1.3%,其检出限为1.1×10-8g/mL。建立了测定香草醛的流动注射化学发光法新方法,并成功地测定了片剂中香草醛的含量,回收率为98%～104%。     

化学发光法测定水产品中链霉素残留

建立了水产品中链霉素残留的化学发光检测方法,最佳条件为:样品用100 g/L三氯乙酸提取后,经C18固相萃取柱净化,以0.1 mol/L NaOH调pH,5×10-4mol/L鲁米诺,5×10-4mol/L高碘酸钾,1×10-9mol/L锰离子为发光体系进行测定,在0.1~5 mg/L范围内,链霉素浓度与发光强度呈现良好的线性关系(r2=0.998 3),以三倍信噪比计算,检出限为0.05μg/g。该方法适用于测定经过前处理的水产样品(虾、鲫鱼和牙鲆)中链霉素的残留,准确度及精密度符合检测要求。     

Ru(phen)32+-SO32--Ce(Ⅳ)体系化学发光法测定葡萄酒中的亚硫酸盐总量

提出了Ru(phen)32+-SO32+-Ce(Ⅳ)体系化学发光法测定溶液中亚硫酸盐的方法.SO32-浓度与化学发光强度在1.0×10-7～1.0×10-4mol/L范围内成正比,检出限为1.97×10-7mol/L(S/N=3),1.0×10-4mol/LSO32溶液重复6次测定结果的相对标准偏差为4.9%.该方法用于测定白葡萄酒中亚硫酸盐总含量为4.006×10-5mol/L,加标回收结果令人满意.     

反相流动注射化学发光法测定姜黄素的研究

姜黄素对鲁米诺 过氧化氢 铬(Ⅲ)体系化学发光具有强烈的抑制作用,基于此首次建立了测定姜黄素的流动注射化学发光分析新方法.实验结果表明,在优化的实验条件下,化学发光信号强度ΔI与姜黄素的浓度在1.0×10-10～1.0×10-8mol/L范围内分段成良好的线性关系,方法检出限为5.0×10-11mol/L,相对标准偏差为2.8%(c=2.0×10-9mol/L,n=11).该法已应用于中药姜黄中姜黄素总量的测定.     

静态注射化学发光法测定对乙酰氨基酚及其发光机理研究

基于对乙酰氨基酚对鲁米诺-过氧化氢-辣根过氧化物酶（luminol-H2O2-HRP）体系的增强作用,建立了静态注射化学发光测定痕量对乙酰氨基酚的新方法,并对体系pH值、发光底物浓度等条件进行优化.通过对比不同混合溶液的紫外吸收光谱以及化学发光光谱,对该体系可能的发光机理进行了初步的探讨.结果发现,对乙酰氨基酚在4.0×10-4～7.5×10-3mol/L浓度范围内其增强发光值的对数与浓度呈良好的线性关系.对3.2×10-3mol/L的对乙酰氨基酚进行10次平行测定,其相对标准偏差为1.68%（n=10）;检测限为1.6×10-4mol/L;回收率为95.0%～103.0%.对乙酰氨基酚的加入改变了luminol-H2O2-HRP体系中激发态的产生速率,从而使发光信号增强.     

Ru(phen)32+-SO32+-Ce(Ⅳ)体系化学发光法测定葡萄酒中的亚硫酸盐总量

提出了Ru(phen)32+-SO32+-Ce(Ⅳ)体系化学发光法测定溶液中亚硫酸盐的方法.SO32-浓度与化学发光强度在1.0×10-7～1.0×10-4mol/L范围内成正比,检出限为1.97×10-7mol/L(S/N=3),1.0×10-4mol/LSO32溶液重复6次测定结果的相对标准偏差为4.9%.该方法用于测定白葡萄酒中亚硫酸盐总含量为4.006×10-5mol/L,加标回收结果令人满意.     

化学发光法测定大气中的二氧化硫

本文提出大气中SO_2的化学发光分析法。方法以酸性K_2Cr_2O_7溶液为吸收液吸收大气中的SO_2生成Cr~(3)。通过Lumino/-H_2O_2-Cr~(3 )体系的化学发光反应间接测定SO_2的含量。工作曲线在1.0×10~(-4)～1.0×10~(-7)mol/L范围内具有良好的线性关系,检出限为2.3×10~(-8)mol/L。相对标准偏差小于2％。本方法简单、快速、灵敏度高,与盐酸副玫瑰苯胺比色法比较,结果一致。     

化学发光微流动注射芯片检测雨水中的过氧化氢

基于在聚甲基丙烯酸甲酯(PMMA)材料上利用激光雕刻微流动注射通道和控制时间进样的模式,并将分离系统(离子交换树脂)引入到微流动注射系统中,结合luminol Co2 H2O2化学发光体系,建立了化学发光微流动注射芯片在线测定过氧化氢的方法.结果表明,采用该方法测定H2O2的线性范围为1×10-4～2×10-7mol/L,检出限为9 5×10-8mol/L,相对标准偏差RSD=2 9%(c=1×10-5mol/L,n=11).与常规的流动注射化学发光分析法相比,该芯片具有简单、操作方便、灵敏度高、分析速度快、尤其是耗样量少等特点,已应用于雨水中过氧化氢的测定.     

一种基于固定化纳米MnO2的流动注射化学发光分析方法

采用电沉积法在自制的碳电极表面制备纳米MnO2,提出了一种基于固定化MnO2流动注射化学发光测量L-色氨酸的分析方法。对所制备的纳米MnO2颗粒采用超景深三维显微镜,扫描电镜以及红外光谱进行了表征。结果表明,所制备的纳米MnO2均匀致密地分布在碳电极表面。用固定化MnO2作为发光试剂,在聚二甲基硅氧烷(PDMS)自制的流通池中进行化学发光反应。选取超纯水作为载液,当含有硫酸和甲醛的L-色氨酸溶液流过流通池与MnO2接触时,即可产生化学发光。线性范围1.0×10-6~5.0×10-5mol/L,检出限8.0×10-7mol/L。通过氧化试剂的固定化,该法简化了流路和测定步骤,具有快速、简单、环境友好以及易于实现自动化控制等优点。     

Degradation of 2, 4-D acid using Mn2+ as catalyst under UV irradiation

In this paper, the oxidative degradation of 2, 4-dichlorophenoxyacetic acid (2, 4-D) using Mn²⁺/H₂O₂ reagent under UV irradiation was studied. The results show that 2, 4-D was degraded more completely in Mn²⁺/H₂O₂ solution than traditional Fenton solutions. The effects of the concentration of Mn²⁺, H₂O₂ and pH were also investigated. And under the optimal condition of 1.48×10⁻⁴ mol/L, 8.99×10⁻⁵ mol/L and pH 3.38, the formation of ·OH was the most, both the decomposition rate of H₂O₂ and the degradation rate of 2, 4-D were the fastest. In addition, the photoreaction process was monitored using spin-trapping electron paramagnetic resonance (EPR), and the results indicated that the oxidative process was predominated mainly by the hydroxyl radical (·OH) gennerated in the system. Biography: HUANG Yingping (1964–), Professor, Ph. D., research direction: pollution ecology and water pollution control.     

Chemiluminescence determination of tetracycline and oxytetracycline in pharmaceutical preparations using Ru (bipy)3 2+-cerium (IV) system

A new chemiluminescence (CL) method for the determination of tetracycline and oxytetracycline is developed, based on the CL reaction of tetracycline and oxytetracycline with Ru (bipy)₃ ²⁺ and Ce (IV). In sulfuric acid medium, the CL emission is generated upon continuous oxidtion of Ru(bipy)₃ ²⁺ by cerium (IV). The emission intensity is greatly enhanced when tetracycline and oxytetracycline are introduced into the reaction system after acid degradation. Under the optimum conditions, the calibration curves are linear over the range of 8.0×10⁻⁸∼4.0×10⁻⁶ mol/L for tetracycline and of 2.0×10⁻⁷∼4.0×10⁻⁵ mol/L for oxytetracycline, with the detection limits are 4.2×10⁻⁸ mol/L for tetracycline and 1.5×10⁻⁷ mol/L for oxytetracycline, respectively. The proposed method was used for the determination of tetracycline and oxytetracycline in pharmaceutical formulations with good results. Foundation item: Supported by the National Natural Science Foundation of China and the Natural Science Foundation of Hubei Province. Biography: HAH He-you (1962), male, Associate profeddor, Ph.D graduate candidate. Present address, Department of Chemistry, Huainan Teacher's College, Huainan.     

HPLC determination of ascorbic acid using luminol-Cu (II) chemiluminescence-application to the analysis of Juice beverage

The chemiluminescence (CL) of luminol-Cu (II) was applied to HPLC determination of ascorbic acid, which was separated by a C₁₈ reverse-phase column with a mobile phase of 0.25 mol/L HAc. The eluted ascorbic acid was mixed with 0.3 mmol/L luminol and 0.05 mol/L CuSO₄. The light emission from the reaction of Cu(II) oxidized ascorbic acid and luminol was detected by a modified luminometer. The detection limit was 3.6×10⁻⁶ mol/L for ascorbic acid at aS/N ratio of 3, and the linear calibration range was 2×10⁻⁴–2×10⁻³ mol/L. The relative standard deviation for 5 replicate injections of 1×10⁻³ mol/L ascorbic acid was calculated as 4.3%. The method was successfully applied to determination of ascorbic acid in juice beverage. Foundation item: National Natural Science Foundation of China (29605001) Biography: Wu Feng-wu(1963-), male, research direction: analytical chemistry.     

Determination of some carbonyl carboxylic acids using chemiluminescent reaction of Ru(bipy)3 2+−Ce(IV)

A coupled chemiluminescence method for the determination of some carboxylic acids was developed, based on their enhancement the chemiluminescence light emission of the reaction of tirs (2,2′-bipyridine) ruthenium(II) and Ce(IV) in sulfuric acid medium. The conditions for their determination were optimized. The following detection limits were obtained: oxalic acid, 2.67×10⁻⁸ mol/L; propandioic acid, 1.20×10⁻⁶ mol/L; pyruvic acid, 1.35×10⁻⁸ mol/L; citric acid, 5.10×10⁻⁸ mol/L; barbituric acid, 2.48×10⁻⁷ mol/L. The proposed method was successfully applied to determination of oxalic acid. The coupled chemiluminescent reaction mechanism and rate equation are proposed. Foundation item: Supported by the National Natural Science Foundation of China and the Natural Science Foundation of Hubei Province Biography: HAN He-you (1962-), male, Associate professor, phD, graduate candidate     

Research at channel level on the effect of LaCl3 on Radish (Raphanus satirus L.) vacuolar membrane

We recorded slow vacuolar (SV-type) channel currents of Radish vacuoles successfully for the first time by using the whole-vacuolar patch-clamp recording mode. SV- type currents would increase and threshold potentials of activation would shift towards more negative values with the increase of concentrations of cytosolic Ca²⁺. When 2.5 mmol/ L LaCl₃ and 4 mmol/L EGTA were added to bath solutions, SV-type currents were suppressed remarkably. Then adding LaCl₃ with different concentrations to pipette solutions, we found that LaCl₃ with higher concentrations (＞4 ´ 10^-7 mol/L) had a strong inhibitory effect on SV-type currents, while LaCl₃ with lower concentrations (≤4 ´ 10^-7 mol/L) promoted channel currents. This promoting effect provides an important basis at channel level for researching further the effects of rare earth on physiological activities of plants and the production-increase effects of rare earth fertilizers on crops.     

Magnetoelectric and converse magnetoelectric res ponses in TbxDy1-xFe2-y alloy ＆ Pb（Mg1/3Nb2/3）（1-x）TixO3 crystal laminated composites

Measured results of magnetoelectric （ME） and converse magnetoelectric （CME） effects of TbxDy1-xFe2-y/ Pb（Mg1/3Nb2/3）（1-x）TixO3/TbxDy1-xFe2-y （TD/PMNT/TD） and PMNT/TD/PMNT laminated composites are presented. ME effect was determined by measuring laminate voltage output under a Helmholtz-generated AC field biased by a DC field （0-1 kOe） （1Oe = 79.58 A/m）. The CME effect was measured by recording the voltage induced in a solenoid encompassing the ME sample while exposed to a DC bias field and PMNT layer driven by a 10 V AC source. The ME and CME responses in the two laminated structure are linear. The highest values of ME coefficients in TD/PMNT/TD and PMNT/TD/PMNT composites are 384 mV/Oe and 158 mV/Oe, respectively, while the highest values of CME coefficients in the two composites are 118 mG/V and 162 mG/V （1 G=10^-4 T）, respectively.     

钴掺杂Mn3O4作为模板制备锂离子电池正极LiMn2O4

以水热合成的钴掺杂Mn₃O₄作为模板,通过固相反应制备尖晶石LiMn₂O₄。XRD谱图和SEM照片显示制备的LiMn₂O₄具有岩石状结构并呈现良好的结晶性,同时Co的引入能够引起LiMn₂O₄晶格的收缩。作为锂离子电池正极材料,Co含量的增加能够提高循环稳定性但降低材料放电比容量,3% Co掺杂的LiMn₂O₄在0.5 C的电流密度下,经过100次循环后,剩余放电比容量达101.6 mAh·g^-1;在10 C的电流密度下,放电比容量可维持在81.0 mAh·g^-1,优于未掺杂的LiMn₂O₄。这是由于Co的引入能够稳定LiMn₂O₄晶体结构并抑制循环中的姜-泰勒扭曲。     

The concentration quenching characteristics of 5D3-7FJ and 5D4-7FJ (J=0―6) transitions of Tb3+ in YBO3:Tb3+ phosphor

The photoluminescence quenching behaviors of ^5D3-^7Fj and ^5D4-^7Fj （J = 0—6） transitions of Tb^3＋ in YBO3：Tb under 130—290 nm excitation were systematically investigated. The results revealed that the quenching concentrations of both ^5D3-^7Fj and ^5D4-^7Fj transitions of Tb^3＋ in YBO3：Tb were mainly dependent on excitation wavelength. Particularly, the quenching concentrations of ^5D4-^7Fj transitions of Tb^3＋ under 130—290 nm excitation were correlated with excitation bands of YBO3：Tb. The quenching concentrations of ^5D3-^7Fj transitions remained at low concentration （2%） under 186—290 nm excitation and then increased gradually with energy of incoming excitation photon when excited at 130—186 nm. This dependence should be involved in their excitation mechanisms and quenching pathway in particular excitation region.[第一段]     

基于植酸锆/普鲁士蓝复合膜的电催化行为研究

通过层层自组装技术,构建植酸锆/普鲁士蓝(Zr-IP_6/PB)多层结构膜.基于普鲁士蓝(PB)对双氧水(H_2O_2)有很高的电催化性能,加之5层植酸锆/普鲁士蓝膜多孔结构有利于传质过程,该H_2O_2传感器具有高灵敏度和高选择性.实验结果显示:修饰电极对H_2O_2响应的物质的量浓度范围为2.00×10~(-5)～1.76×10~(-3) mol·L~(-1),线性相关系数R=0.998 9.     

流动注射分析法测定水样中的NO2--N和NO3--N

采用流动注射技术测定水样中的NO-/2-N和NO-/3-N.以N-(1-萘基)乙烯二胺盐酸盐和对氨基苯磺酸为显色剂,在540nm下比色测定NO-/2-N的含量.水样中的NO-/3-N,在稀醋酸条件下用锌粉将其预还原成NO-/2-N后,也在上述相同的条件下测定其含量.NO-/2-N的检出限为0.005×10-/6,NO-/3-N的检出限为0.05×10-/6,分析速度为65次/小时.