H2O2-鲁米诺-荧光素钠-K2CO3高灵敏化学发光法测定二氧化碳

在碱性介质中, CO₃^2－对H₂O₂氧化鲁米诺化学发光反应具有重要作用, 荧光素钠对该反应具有很强的增敏作用. 据此, 建立了化学发光法测定二氧化碳的新方法. 方法的线性范围为1.0×10^－10～5.0×10^－6 mol•L^－1 CO₃^2－, 检出限为 1.2×10^－11 mol•L^－1 CO₃^2－ (相当于5.3×10^－10 g•L^－1 CO₂). 该方法用于室内外空气中二氧化碳含量的测定, 相对标准偏差1.8%～2.1% (n＝11), 加标实验回收率97.6%～101.4%. 论文还探讨了反应的发光机理, 发光反应很可能是由溶液中的CO₃^2－与H₂O₂作用而产生的活性自由基引发, 荧光素钠对发光的增敏作用为化学能量转移过程.     

Luminol-H2O2-纳米银化学发光体系测定5-磺基水杨酸

碱性条件下,5-磺基水杨酸对Luminol-H2O2-纳米银化学发光体系有较强的增敏作用,据此,结合流动注射技术,建立了测定5-磺基水杨酸的新方法。在最佳实验条件下,5-磺基水杨酸浓度在1.5×10-8～2.0×10-6mol/L范围内与相对发光强度呈线性关系,检出限(3σ)为1.0×10-9mol/L。对4.0×10-7mol/L的5-磺基水杨酸平行测定9次,相对标准偏差为2.7%。该法用于强力霉素废水中5-磺基水杨酸的测定,结果令人满意。     

CoHR--H2O2-鲁米诺化学发光体系与应用

研究了钛铁试剂（Ｈ２Ｒ２－）与Ｃｏ（Ⅱ）形成的配合物ＣｏＨＲ－,对Ｈ２Ｏ２氧化鲁米诺的增强作用,基于此建立了钴的化学发光分析新方法。新方法Ｃｏ（Ⅱ）的检出限为１．２９×１０９ｇ／Ｌ,工作曲线线性范围为５×１０８～１．０×１０５ｇ／Ｌ,检测１×１０７ｇ／ＬＣｏ（Ⅱ）离子的相对标准偏差为２．５％以内。直接用于制药厂废水中微量钴的测定,结果满意     

高碘酸钾-鲁米诺后化学发光反应的研究——流动注射-后化学发光法测定异烟肼

实验发现了异烟肼在高碘酸钾-鲁米诺化学发光反应体系中的后化学发光反应。在对这一后化学发光反应的动力学性质、化学发光光谱、荧光光谱、紫外可见吸收光谱以及一些相关问题研究的基础上,讨论了其可能的反应机理;建立了利用此后化学发光反应测定异烟肼的流动注射化学发光新方法。方法的线性范围为1.0×10-9~4.0×10-7g/mL,检出限为6×10-10g/mL,对5.0×10-8g/mL的异烟肼进行11次平行测定的相对标准偏差为1.7%。此法已用于异烟肼片剂中异烟肼含量的测定,结果与药典法测定值一致。     

利用鲁米诺-过氧化氢-铬(Ⅲ)化学发光体系测定痕量砷

本法与原子吸收法相比,检测下限由1.0×10-9g/mL降至6.0×10-12g/mL,线性范围由1.0×10-9～1.0×10-6g/mL扩大至1.0×10-10～1.0×10-5g/mL,且具有灵敏度高,选择性好,设备简单,操作简便等诸多优点,同时,在操作中不会产生ASH3这样的有毒气体,避免了分析工作人员的健康受到损害.方法目前尚未见文献报道.     

流动注射-鲁米诺-铁氰化钾反应体系化学发光法测定依诺沙星

试验发现依诺沙星对鲁米诺与铁氰化钾之间的化学发光反应具有显著的增敏作用,而且当依诺沙星浓度在2.0×10-8～2.0×10-5mol·L-1范围内,与相应的化学发光增强信号值(△I)之间呈线性关系,其检出限(3S)为5.7×10-9mol·L-1,取1.0 × 10-6mol·L-1依诺沙星按试验方法测定11次,算得其相对标准偏差为1.75%.结合应用流动注射技术,提出了流动注射-化学发光法(FI-CL)测定药片中依诺沙星的方法,应用此方法分析了3个依诺沙星片剂试样,所测得的结果与其标示值相符.按标准加入法作了回收率试验,所得结果在96.7%～103.0%之间.     

钒(Ⅴ)-亚铁氰化钾-鲁米诺化学发光体系测定钒

本文利用钒(Ⅴ)-亚铁氰化钾-鲁米诺化学发光体系建立了痕量钒的化学发光测定法。方法检出限是2×10~(-10)g/mL钒,线性范围是4×10~(-10)～1×10~(-7)g/mL钒,测定的相对标准偏差小于2%,考察了26种常见离子的干扰情况。方法已用于水样中痕量钒的测定。     

用鲁米诺-KIO4-Fe(1, 10-phen)32+体系的化学发光法测定痕量铁

本文利用鲁米诺-KIO₄-Fe(1,10-phen)₃²⁺配合物体系产生化学发光反应,建立了测定痕量铁的新的化学发光分析方法.该法以1,10-phen为配位体,铁的检出限为1.6×10^-7g/L,工作曲线响应浓度范围在1×10^-5-1×10^-3g/L.在测定2×10^-4g/L铁的相对标准偏差为3.5%.用于检测工业沉淀BaSO₄中痕量铁获得满意结果.     

溴酸钾-鲁米诺后化学发光法检测水中微量偏二甲肼

实验发现偏二甲肼(UDMH)在溴酸钾-鲁米诺化学发光反应体系中的后化学发光反应.在对这一后化学发光反应的动力学性质、发光条件,包括溴酸钾浓度、鲁米诺浓度、管长、流速和酸碱度条件等研究的基础上,建立了后化学发光反应法测定偏二甲肼的新方法,并讨论了其可能的反应机理.该方法的线性范围为1.0×10-7～1.0×10-5g/L...     

Continuous Flow Determination of Carbon Dioxide in Water by Membrane Separation-Chemiluminescent Detection

Abstract

Carbon dioxide has been found to enhance the chemiluminescence of a luminol system. A determination method for carbon dioxide in water was developed by applying this reaction to a continuous flow membrane-separation system. Concentrations of carbon dioxide as low as 0.04 μ g C /mL were determined. Membrane-separation effectively eliminates interferences from Co(II), Cr(III), Fe(III), and other ions which also enhance chemiluminescence. The relative standard deviation for this method was 2.8% (n=5) for 4.0 μ g C /mL and the time required for the analysis of one sample was 3.0 min.     

Kinetics of carbon dioxide sorption by the composite material K2CO3 in Al2O3

The kinetics of the CO₂ sorption by a composite sorbent K₂CO₃ in Al₂O₃ was studied in a gradientless adsorber at 295 K. The order of the sorption rate with respect to the CO₂ concentration was found to be n = 1.04 ± 0.07. The sorption rate constants were evaluated for sorbent grains of various sizes between 0.25 and 2.1 mm. It was shown that the rate constant is proportional to the grain reciprocal radius. The dynamic capacity was obtained as a function of the CO₂ concentration. The maximum sorption capacity was found to be 83 mg of CO₂ per 1 g of the sorbent. This revised version was published online in August 2006 with corrections to the Cover Date.     

超临界二氧化碳中PdCl2-CuCl2体系催化末端炔烃氧化偶联反应

研究了在超临界二氧化碳中实现PdCl₂-CuCl₂体系催化末端炔烃的氧化偶联反应, 研究结果表明: 催化剂、超临界二氧化碳及其共溶剂对反应结果有着重要的影响, 炔烃的取代基会影响末端炔烃在氧化偶联反应中的反应活性.     

Kinetics of Mn2O3 digestion in H2SO4 solutions

The kinetics of Mn₂O₃ digestion in various H₂SO₄ solutions (0.5-2.0 M) and at various temperatures (ambient to 80 °C) to form solid γ-MnO₂ and soluble Mn(II) have been examined using X-ray diffraction. Using a modified first-order Avrami expression to describe digestion kinetics, rate constants in the range 0.02-0.98 h⁻¹ were found for Mn₂O₃ disappearance, and 0.03-0.42 h⁻¹ for γ-MnO₂ formation, with higher H₂SO₄ concentrations and temperatures leading to faster conversion rates. Also, for a particular set of experimental conditions, the rate of γ-MnO₂ formation was always slower than Mn₂O₃ disappearance. This was interpreted in terms of the solubility and stability of the soluble Mn(III) intermediated formed during the digestion. Activation energies for Mn₂O₃ dissolution and γ-MnO₂ formation were also determined.     

La2O3/γ-Al2O3催化剂用于二甲醚二氧化碳重整制氢

采用等体积浸渍法制备了不同负载量的La₂O₃/γ-Al₂O₃催化剂,并考察了负载量和反应温度对催化剂用于二甲醚二氧化碳重整制氢反应的性能影响。结果表明,反应温度为550℃、La₂O₃负载量为15%时,催化剂表现出最好的性能：二甲醚的转化率为100%,二氧化碳的转化率达到85.4%,产物氢气的选择性高达93.3%,一氧化碳的选择性为76.04%,副产物甲烷的选择性仅为6.3%。550 ℃时其平均积炭速率为1.387 5 mg/（g·h）。研究还利用XRD、BET、TEM、TG等方法对催化剂进行了表征。     

纳米Li_2ZrO_3吸收剂原位移除CO_2强化水煤气变换反应制氢

采用浸渍法制备了在水煤气变换(WGS)反应中具有高催化活性的Ni/γ-Al2O3催化剂,使用柠檬酸法合成出高效CO2吸收剂Li2ZrO3纳米材料.在固定床微反应器上对WGS和吸附强化水煤气变换(SE-WGS)反应制氢过程进行了比较研究.前者只使用20%Ni/γ-Al2O3催化剂,而后者将20%Ni/γ-Al2O3催化剂与纳米Li2ZrO3吸收剂混合装填.结果表明,纳米Li2ZrO3具有比已报道的CO2吸收剂更快的吸收速率及优异的吸脱附循环稳定性,可应用于吸附强化过程,通过原位吸收WGS反应产生的CO2,使得反应超越化学平衡限制,直接制得高纯度H2.在823K,0.1MPa和H2O/CO=4的条件下,在SE-WGS过程一步制得纯度高于98%的H,验证了吸附强化反应进程制高纯氢的可行性.     

Highly Sensitive Determination of Concanavalin A Lectin Based on Silver-Enhanced Electrogenerated Chemiluminescence of Luminol

A highly sensitive bioassay based on silver-enhanced luminol electrogenerated chemiluminescence (ECL) is reported for the determination of concanavalin A lectin. A gold electrode modified with the mixed self-assembled monolayer of thiolated mannoside and mercaptohexanol was used to selectively capture a target lectin, concanavalin A, through the specific interaction between mannoside and concanavalin A. Mannoside-functionalized gold nanoparticles were further introduced to the opposite binding sites of the tetrameric concanavalin A to form a sandwich-type complex. Silver enhancement step was performed to coat the surface of mannose-stabilized gold nanoparticles with silver. The deposited silver was dissolved in an acidic solution and further neutralized. The resulting silver ions were finally detected with luminol electrogenerated chemiluminescence, in which the silver ions greatly enhanced the chemiluminescence intensity. The present electrogenerated chemiluminescence bioassay detected concanavalin A from 0.190 to 10.0?µg/mL (r²?=?0.999) with a detection limit of 0.146?µg/mL (signal to noise ratio?=?3), which is much lower compared to previously reported methods such as microgravimetry, surface plasmon resonance, and colorimetry. Furthermore, the present bioassay showed good selectivity over possible interfering lectin proteins.     

Highly Efficient Quasi-Homogeneous System for Photocatalytic H2O2 Production

<正>Hydrogen peroxide（H₂O₂） has received much attention as a promising highly efficient and environmentally benign oxidant, which is widely used in organic synthesis, wastewater treatment and energy field. Especially, H₂O₂ is completely soluble in water and easy to transport, making it an ideal energy carrier to replace H₂. To date, the traditional methods of producing H₂O₂ mainly include anthraquinone oxidation an...     

CO2 在高分散 Ni/La2O3 催化剂上的甲烷化

 以 La2O3 为载体, 采用浸渍法制备了 10%Ni/La2O3 催化剂, 考察了该催化剂的 CO2 甲烷化反应性能. 结果表明, 在较低的温度 (350 oC) 和高空速 (约 30000 h–1) 下, 甲烷时空收率可大于 3000 g/(kg•h), 无论转化率高低, 甲烷选择性始终保持在 100%. X 射线衍射和 H2-程序升温还原等表征结果表明, CO2 在 Ni/La2O3 催化剂上的加氢机理可能与 Ni/γ-Al2O3 上不同, 并且 La2O2CO3 的形成有利于提高催化剂活性.     

有序介孔氮掺杂碳负载三氧化二铁的制备及其催化氧还原性能

制备了有序介孔氮掺杂碳负载三氧化铁,有效降低了氧还原的过电势。通过扫描电子显微镜、透射电子显微镜、氮气吸附-脱附测试、粉末X射线衍射、X射线光电子能谱、拉曼光谱等技术表征了所制备的催化剂的物理化学性质。此外,用旋转圆盘电极测试了其在碱性条件下对氧还原反应的催化活性和选择性。实验结果表明:氮气热解后铁以三氧化二铁的形式负载于有序介孔氮掺杂碳中,其比表面积达到755 cm^2·g^-1。拉曼和X射线光电子能谱结果表明,加入铁前驱体后所制备的催化剂石墨化程度有所提升、阻抗降低、导电性增加。在碱性条件下,Fe2O3@NC催化剂呈现出4电子氧还原反应,其起始电位(-0.01 V vs Ag/AgCl)和半波电位(-0.13 V vs Ag/AgCl)与商用20%Pt/C相当。此外,该催化剂具有较好的抗甲醇性能且其恒电压稳定性优于商用Pt/C。Fe2O3@NC催化剂用于锌-空电池放电测试,其放电功率可以达到88 mW·cm^-2,是商用Pt/C的1.29倍。