磷钼杂多酸光度法测定吲哚乙酸

研究了吲哚乙酸与磷钼杂多酸在浓度为 0 .0 3 mol/L的硫酸介质中发生氧化还原反应 ,形成的还原产物 (钼蓝 )在 NH3-NH4Cl缓冲溶液 (p H8.4)中最大吸收波长为 314 nm,表观摩尔吸光系数 ε值为 3.5 4× 10 4L· mol-1·cm-1 ,吲哚乙酸含量在 5 .0× 10 -7～ 5 .0× 10 -5 mol/L范围内符合比尔定律 ,检出限为 1.0× 10 -7mol/L,对 2 .0 0× 10 -5 mol/L吲哚乙酸测定 10次的相对标准偏差为 6 .42 % ,加标回收率为 94.2 %～ 10 0 .1%     

硅钼杂多酸示波极谱法测定抗坏血酸

本文研究了硅钼杂多酸与抗坏血酸的反应,发现其产物在示波极谱上于～1.12V(vs.SCE)产生灵敏吸附波,导数波高与抗坏血酸浓度在1×10~(-7)mol/L～4×10~(-5)mol/L有线性关系。检测限为5×10~(-8)mol/L。本法应用于针剂,片剂及柑桔中抗坏血酸的测定,得到满意结果。     

三维荧光光谱法连续测定苯胺、二苯胺和N-甲基苯胺

本文比较了苯胺、二苯胺、N-甲基苯胺的二维荧光光谱和三维荧光光谱。提出了同时测定苯胺,二苯胺和N甲基苯胺的分析方法,它们的浓度分别在2.0×10~(-7)～5.0×10~(-6)mol/L,9.0×10~(-8)～7.4×10~(-6)mol/L,1.3×10~(-7)～2.0×10~(-8)mol/L范围内有良好的线性关系,检出限为1.0×10~(-7)mol/L,8.0×10~(-9)mol/L,1.0×10~(-7)mol/L.相对标准偏差分别为5％,7％,7％.此方法用于混合样品和工业废水的分析,获得较满意的结果.     

海洛因对别洛索夫-扎鲍京斯基振荡化学反应的影响及其分析应用

研究了海洛因对Belousov Zhabotinsky(B Z)振荡反应的影响 ,结果表明 :海洛因的加入明显地改变了振荡体系的周期和振幅 ,即对振荡体系产生扰动 ,扰动的浓度范围为 1.8× 10 -8～ 2 .1× 10 -3 mol/L ,且海洛因的浓度分别在 3.8× 10 -6～ 2 .8× 10 -5mol/L和 0 .9× 10 -6～ 2 .9× 10 -5mol/L范围内与振荡周期改变值ΔT和振幅改变值ΔA均呈现良好的线性关系 ,相关系数分别为 0 .9931和 0 .974 6。据此 ,建立了测定海洛因的新方法。     

同一体系中铜(Ⅱ)、铅(Ⅱ)、镉(Ⅱ)、镍(Ⅱ)和钴(Ⅱ)的络合物吸附波及其分析应用

研究了丁二酮肟 氨 氯化铵 柠檬酸钠 明胶 抗坏血酸体系中Cu(Ⅱ )、Pb(Ⅱ )、Cd(Ⅱ )、Ni(Ⅱ )和Co(Ⅱ )的络合物吸附波 ,建立了同时测定水溶液中痕量相应元素的新方法。上述金属络合物分别在 -0 .44、-0 60、-0 .76、-1.0 7和 -1.2 4V左右产生灵敏的极谱波。信噪比为 3时 ,检出限分别为 1.0× 10 - 8、2 .3×10 - 8、1.3× 10 - 8、2 .9× 10 - 1 0 和 3 .6× 10 - 1 1 mol/L。铜、铅、镉、镍和钴的浓度分别为 2 .0× 10 - 8～ 2 .0× 10 - 5,4.8× 10 - 8～ 4.8× 10 - 5,3 .0× 10 - 8～ 3 .0× 10 - 5,5 .4× 10 - 1 0 ～ 5 .4× 10 - 7和 6.8× 10 - 1 1 ～ 6.8× 10 - 8mol/L时 ,与相应峰电流线性关系良好。方法用于同时快速测定实际样品中这些金属离子 ,获得满意结果     

血红蛋白模拟过氧化物酶催化反应体系的极谱分析

用极谱分析法研究了血红蛋白催化H2O2氧化邻苯二胺(OPD)的反应体系.血红蛋白具有类似过氧化物酶的功能,它能够催化OPD-H2O2的反应生成一种具有电化学活性的产物,该产物在滴汞电极上-0.64V(vs.SCE)产生一个峰形良好的极谱还原峰.优化了血红蛋白的催化反应条件和催化反应产物的极谱测定条件 在最佳条件下,该体系可用于血红蛋白含量的测定,线性范围为2.0×10-9～2.0×10-7mol/L,检测限为1.0×10-9mol/L;也可用于痕量H2O2的测定,线性范围为1.0×10-6～2.0×10-4mol/L,检测限为1.0×10-6mol/L.     

钒-络蓝黑R络合物在碳糊电极上的阳极吸附伏安法研究及痕量钒的测定

研究了钒-络蓝黑R(EBBR)络合物在碳糊电极上的吸附伏安行为。在pH4.7的0.2mol.L-1HOAc-NaOAc缓冲溶液,于0.4V富集,从0.4~1.4V以300mV.s-1的速率线性扫描。在1.17V(vs.SCE)的二次导数氧化峰电流与钒的浓度在9.0×10-10~6.0×10-8mol.L-1(1.2×10-6mol.L-1EBBR)和6.0×10-8~6×10-7mol.L-1(3.0×10-6mol.L-1EBBR)范围内呈线性关系,富集450s,检出限为4.0×10-10mol.L-1(S/N=3)。该法用于花生仁和自来水样中钒的测定,结果满意。     

悬汞电极1.5次微分吸附溶出法测定痕量雌激素

雌激素与亚硝酸钠在一定条件下反应,其硝基衍生物具有良好的电活性,能在汞电极上吸附还原.在0.01 mol/L的硼砂介质中,还原电流大小与雌激素的浓度在1×10~(-6)～1×10~(-9)mol/L范围内有较好的线性关系.用1.5次微分溶出法可测定2×10~(-10)mol/L的雌激素.此法已应用于孕妇尿中雌三醇的测定,结果良好.     

氨基黑10B褪色光度法测定两种阳离子表面活性剂及其作用机理

在弱酸性的乙酸盐介质中,阳离子表面活性剂(CS)与氨基黑10B(AB)染料反应,形成离子缔合物,溶液颜色发生明显褪色,最大吸收在616 nm,CS的浓度在0~2.17×10-5mol.L-1(CPB)、0~2.09×10-5mol.L-1(CTMAB)范围内遵守比耳定律,表观摩尔吸光系数为2.16×104L.mol-1.cm-1(CPB)、1.93×104L.mol-1.cm-1)(CTMAB),检出限为7.64×10-7mol.L-1(CPB)、1.31×10-6mol.L-1(CTMAB)。用于水样中CS的测定,还用密度泛函理论对反应机理进行了探讨,结果与试验事实相符合。     

胶束增敏荧光光度法测定土霉素的研究

提出了表面活性剂增敏的酸性降解荧光法测定土霉素的新方法。土霉素与浓H2SO4反应,生成强荧光降解物一脱水土霉素,在pH10.0的NH3 NH4Cl缓冲溶液中,CTMAB的存在对脱水土霉素的荧光有较强的增敏和增稳作用,土霉素含量在1.21×10-8mol/L～4.83×10-6mol/L范围内与荧光强度成正比,方法的检出限为6 66×10-9mol/L。应用本法测定片剂中的土霉素,平均回收率为99.6%(n=5)。     

铁锌柱撑膨润土催化剂的制备及其对甲基橙废水的光催化降解性能

采用微波辐照促进的溶胶浸渍法制备了铁锌柱撑膨润土催化剂;用制备的催化剂对甲基橙溶液在可见光照射下进行降解,探讨了铁负载量、H2O2质量浓度、溶液初始pH、反应时间和催化剂投加量对甲基橙降解率的影响,并考察了催化剂的重复利用性能.结果表明,在pH为3、H2O2质量浓度100mg/L、催化剂投加量1.5g/L、反应时间为2h条件下,甲基橙降解率可达97%.     

Keggin型铜取代磷钨杂多阴离子可见光催化降解罗丹明B

以Keggin型铜取代杂多阴离子PW11O39Cu(Ⅱ)(H2O)5-[PW11Cu]为可见光催化剂,有机染料罗丹明B(RhB)为模型污染物,研究了在可见光照射下PW11Cu对RhB的可见光催化降解作用,提出了PW11Cu可见光催化作用的反应机理,同时考察了RhB初始浓度、PW11Cu初始浓度和溶液pH值对RhB光催化降解速率的影响。 实验结果表明,含有15.6 μmol/L PW11Cu+10 μmol/L RhB的水溶液在可见光照射下反应80 min,RhB的降解率达100%,总有机碳去除率约33%。 RhB的可见光催化降解服从准一级动力学方程,在RhB初始浓度为20、30和40 μmol/L的情况下,其表观一级速率常数分别为3.1×10-2、2.0×10-2和1.5×10-2 min-1。     

Photoinitiation rate profiles during polymerization of a dimethacrylate-based resin photoinitiated with camphorquinone/amine. Influence of initiator photobleaching rate

The photodecomposition of camphorquinone (CQ)/amine during the photo polymerization of a dimethacrylate-based resin under continuous irradiation was investigated in thick samples. The global CQ photoconsumption was measured by monitoring the decrease in light absorption as a function of irradiation time and the kinetics were satisfactory fitted to a first order expression where the rate constant of photobleaching was proportional to the irradiation intensity. In a thick sample, the photobleaching of the photoinitiator is accompanied by a deeper penetration of the light through the underlying layers. These gradients of photoinitiator concentration, light intensity and photoinitiation rate along the path of irradiation were calculated. The photodecomposition reaction was spatially inhomogeneous and the degree of nonuniformity increased with increased initial sample absorbance. The influence of the photobleaching process on the polymerization reaction was examined. The photobleaching rate of CQ was much slower than the polymerization rate and only 20% of the initial amount of CQ was consumed before the polymerization reaction had almost ceased. Results obtained in this research highlight the inherent interlinking of light attenuation and photobleaching rate in bulk polymerizing systems.     

Research on photodegradation of formaldehyde by nanocrystalline N-TiO<Subscript>2</Subscript> powders under visible light irradiation

The photo-degradation of formaldehyde (HCHO) by nitrogen-doped nanocrystalline TiO₂ (N-TiO₂) powders under visible light irradiation has been systematically investigated. Experimental results show that the degradation ratio reached up to 42.6% after 2 h visible light irradiation when the amounts of N-TiO₂ powders were 0.5 g, the initial concentration of the HCHO was set at 0.98 mg/m³, the illumination intensity was fixed at 10,000 lux, the ambient temperature was set at 26 °C, and the relative humidity was maintained at 33 ± 5%. Further research shows that the degradation ratios were all larger than 40% in ten repeated cycles of photodegradation of HCHO by N-TiO₂ powders. The degradation ratio was as high as 82.9% after 2 h visible light irradiation when the amount of N-TiO₂ was 5 g. The degradation ratio was increased from 25.5 to 59.6% when the illumination intensity of the visible light was increased from 0 to 30,000 lux. However, the degradation ratio could not be further increased by further increasing the illumination intensity.     

浅池型TiO2/ACF光催化降解水中苯酚的研究

为了提高光催化过程的降解速率，本文以涂覆法制得的二氧化钛/活性炭纤维（TiO2/ACF）为光催化剂，300 W(365 nm)高压汞灯为光源，研究了浅池型反应器中苯酚在TiO2/ACF上的光催化降解动力学；探讨了光强度、高压汞灯滤光以及光源种类对降解反应的影响，并对光氧化，光催化和吸附过程进行了比较。结果表明：光氧化对苯酚的降解无效果，光催化降解速率常数与吸附速率常数之比为3.35/1；光强越大，光催化降解速率越快；高压汞灯不滤光时光催化降解速率明显加快，但光催化反应仍遵循准一级反应动力学方程；波长为254 nm紫外杀菌灯的降解效果高于波长为365 nm高压汞灯滤光后的降解效果。     

OpticalIy Pumped Chemiluminescence of Indole-3-Acetic Acid

Optically pumped chemiluminescence of indole-3-acetic acid (IAA) was observed and studied. Rose Bengal (RB) was used as a photosensitizer. Long-lived chemiluminescence (CL) appeared after irradiation of the IAA/RB reaction mixture by monochromatic light at 550 nm (the maximum of RB absorption) or by visible light. The CL spectrum had a maximum at 480 nm. The kinetics of the CL decay were single exponential. Single-exponential kinetics were characterized by two experimentally measured values: initial CL intensity and exponential lifetime of the CL decay. We studied the influence of five parameters: (1) the rate of irradiation fluence, (2) the time of irradiation, (3) RIB concentration, (4) IAA concentration and (5) buffer pH on the initial CL intensity and the CL lifetime. Initial CL intensity was proportional to the rate of irradiation fluence and the concentration of RB. Saturation was observed in dependencies of initial CL intensity on the time of irradiation, the concentration of IAA and the buffer pH. The lifetime of the CL decay decreased with increasing pH and did not depend on the other four parameters. The mechanism explaining the experimental results was suggested and detailed kinetic analysis was performed to prove the proposed mechanism. Quantum yield of the CL and five rate constants that are involved in the mechanism were determined.     

太阳光照射浮石负载二氧化钛降解氨氮废水

采用溶胶-凝胶法制备了Ti O_2,并使Ti O_2负载在浮石上制备Ti O_2/浮石光催化剂。用X射线荧光光谱(XRF)、电镜扫子显微描(SEM)和傅里叶红外光谱(FT-IR)表征浮石、Ti O_2及Ti O_2/浮石。在太阳光照射下,用Ti O_2/浮石处理模拟氨氮废水,以废水中氨氮降解率为标准,考察影响氨氮降解因素。结果表明,Ti O_2成功固定在浮石表面,负载率为3.71%;废水中氨氮降解率随太阳光照射时间、废水p H值、催化剂Ti O_2/浮石含量增加而增大。当初始氨氮浓度为500 mg/L、太阳照射180 min、废水p H=11、催化剂Ti O_2/浮石剂量为20 g/L时,氨氮降解率达82.0%,氨氮除去率86.8%,降解产物中未发现污染成分NO_2~-和NO_3~-产生。催化剂再生/催化3次,每次再生后氨氮降解率约下降10.0%。该方法快速、简单、低消耗和产生二次污染少,能有效地降解废水中的氨氮。     

Ag@AgBr光催化剂的制备及其可见光催化降解亚甲基蓝反应性能

采用沉积-沉淀及光还原法制备了Ag@AgBr等离子体光催化剂,利用X射线衍射、扫描电镜和紫外-可见漫反射光谱对其进行了表征,并考察了该等离子体光催化剂在可见光(λ420nm)下的催化性能,探讨了催化剂用量、pH值、亚甲基蓝初始浓度、H2O2添加量、循环使用及捕获剂对Ag@AgBr催化性能的影响.结果表明,当亚甲基蓝的初始浓度为10mg/L,催化剂用量为1g/L,pH=9.8时,光照12min后,亚甲基蓝的降解率高达96%,且样品经5次循环使用后活性基本保持不变;而少量H2O2的添加对光催化活性影响不大,过量的H2O2会降低光催化活性;乙二胺四乙酸捕获空穴后比异丙醇捕获·OH后的光催化活性降得更低.同时,对Ag@AgBr等离子体光催化剂可见光降解亚甲基蓝的催化机理进行了分析.     

氟铌酸钾的低温固相法合成及其对甲基橙的光催化降解性能

以草酸铌、草酸钾和氟化钾为原料,采用改进的固相法在较低温度(600℃)下合成了层状K2NbO3F;测定了其对甲基橙光催化降解的催化作用,并基于紫外-可见漫反射光谱分析和X射线衍射分析初步探讨了甲基橙在自然光照条件下的光催化反应过程及降解机理.结果表明,合成的K2NbO3F与微量H2O2作用后,在自然光照条件下几乎可以使甲基橙染料完全降解;当反应温度为45℃,催化剂投加量为1g/L,H2O2用量为0.33%(体积分数)时,2h内可将初始浓度为15mg/L的甲基橙溶液几乎完全降解.就甲基橙的光催化降解机理而言,·OH自由基在其降解过程中起重要作用.     

声化学降解染料结晶紫的研究

采用频率为20 kHz的超声波降解阳离子染料结晶紫(CV)溶液,考察了溶液初始浓度、pH值、声能强度、时间、温度等因素对染料声化学降解过程的影响.实验结果表明,溶液初始浓度为30 mg/L、pH=8.0、声强=47.5 W/cm2、超声辐照50 m in,CV的脱色率达97.8%;CV的超声降解过程以高温热解反应为主,服从动力学一级反应;当超声/H2O2、超声/镁联合作用时,二者产生协同效应,溶液中产生大量OH自由基,强化了CV的声化学脱色和降解过程.