共查询到20条相似文献,搜索用时 0 毫秒
1.
2.
无外加过氧化氢时氯化血红素催化性能的研究 总被引:1,自引:0,他引:1
研究了在十二烷基苯磺酸钠胶束介质中,氯化血红素对溶解氧氧化水杨基荧光酮的催化性能,发现该体系满足Michaelis-Menten方程,在pH8.6的条件下,测得Km和Vmax值分别为7.94×10^-5mol/L和0.113s^-1。利用反应平衡法分光光度法可测定6.0×10^-8 ̄7.2×10^-7mol/L的Hemin。 相似文献
3.
利用卟啉(Hemin)具有模拟酶的功能,与多壁碳纳米管(MWCNTs)构建了一种新型的过氧化氢(H2O2)生物传感器。首先,利用Hemin与MWCNTs之间的π-π键作用,在超声分散下制备Hemin/MWCNTs纳米复合物;采用滴涂技术并在nafion的作用下将其固载在电极表面,制得该H2O2生物传感器(nafion/Hemin/MWCNTs/GCE)。采用紫外-可见分光光度法(UV-Vis)对合成的纳米复合物进行了分析;采用扫描电镜(SEM)对电极的表面形貌进行了表征;采用循环伏安法和计时电流法考察了该修饰电极的电化学行为;并对传感器的行为进行了详细的研究。在最优条件下,此修饰电极对H2O2具有明显的催化作用,电流与H2O2的浓度在6.0×10-7~1.8×10-3 mol/L范围内呈现良好的线性关系,检出限达2.0×10-7 mol/L。此传感器制作简单,具有较高的灵敏度和良好的稳定性及重现性。 相似文献
4.
In an ammonium buffer medium at pH 8.9–9.5, hemin exhibits mimetic peroxidase activity, and has a catalytic effect on the oxidative decoloration of bromopyrogallol red (BPR) with hydrogen peroxide. On this basis and in presence of ethanol as an effect-enhancing agent, a spectrophotometric determination of hydrogen peroxide is described with an apparent molar absorptivity of 4.00×104?l?mol?1?cm?1 and a linear range from 3.2×10?7 to 3.2×10?5?mol?l?1. BPR has advantages over some of widely used chromogenic substrates in aspects of sensitivity, simplicity and detection wavelength, while hemin has better stability than peroxidase. The system can be easily coupled with a glucose oxidase-catalyzed reaction, and glucose in the concentration range of 6.0×10?7? 3.2×10?5?mol?l?1 is spectrophotometrically determined. The method has been applied to the analyses of synthetic water and human serum samples. The Michaelis parameters and the mechanism of the mimetic peroxidase reaction are also investigated. 相似文献
5.
1 引 言过氧化氢的测定在医学和环境科学中都具有很重要的意义。目前已有许多测定过氧化氢的方法 ,如光度法、荧光法、电分析法及化学发光法等。四磺基锰酞菁 (MnTSPc)是一种与金属卟啉有着类似母体结构的金属酞菁类化合物 ,它具有过氧化物模拟酶的性质。继前文用对羟基苯乙酸和L 酪氨酸两种经典荧光底物成功实现对过氧化氢进行荧光分析测定后 ,我们又发现 ,用邻苯二胺 (OPD)做底物 ,以MnTSPc催化其与过氧化氢反应 ,也可实现对过氧化氢的高灵敏测定。本文研究了此催化荧光反应的最佳条件 ,建立了测定过氧化氢的催化荧光分析新方法 … 相似文献
6.
7.
氯化血红素模拟过氧化物酶高效液相色谱柱后衍生法测定过氧化氢和水溶性有机过氧化物 总被引:4,自引:0,他引:4
研究了氯化血红素(Hemin)模拟辣根过氧化物酶(HRP),对羟基苯乙酸(PHPAA)作 底物,高效液相色谱(HPLC)柱后衍生荧光法测定H2O2和水溶性有机过氧化物的方法。采用 Hemin作催化剂柱后衍生反应的最佳pH值约为11,与荧光检测pH值一致,使得以往HPLC 柱后衍生方法所需的高压泵从3台减少到2台,而一些不能作为HRP底物的羟烷基过氧化 物在pH值≥10的溶液中迅速水解为H2O2从而得到测定。优化了测定H2O2和甲基过氧化 氢(CH3 OOH, MHP)的条件。最佳条件下 Hemin方法测定 H2O2的检测限为 9.0 × 10-9 mol/L, 测定 MHP的检测限为 2.0 × 10-7 mol/L。 相似文献
8.
Theodosios S. Sikalos Yannis M. Arabatzis Mamas I. Prodromidis Panayotis G. Veltsistas Miltiades I. Karayannis 《Mikrochimica acta》2000,135(3-4):197-201
In this work a kinetic spectrophotometric method for the determination of trace amounts of vanadium is presented. The method
is based on the catalytic effect of the vanadium(V) on the reaction between diphenylamine (DPhA) and hydrogen peroxide in
a concentrated solution of formic acid. The formation of the deep-blue oxidation product is followed by a filter spectrophotometer,
equipped with an optical fiber assembly, on line with a PC provided with the suitable software. The measurements were taken
at 583 nm, with an immersed type cell of 1 cm light path length. The optimization of the operating conditions regarding concentrations
of the reagents, temperature and interferences are also investigated. The working curve is linear over the concentration range
0.40–4.0 μg/ml vanadium(V). The relative standard deviation for a standard solution of 0.6 μg/ml of vanadium is 0.5% (n = 5).
The proposed method proved highly sensitive, selective and relatively rapid for the assay of vanadium, at low level of 0.40 μg/ml
without any pre-concentration step. The method was applied to alloys and cosmetics samples. The results were compared to those
received with a reference method. Good agreement was attained, with a mean error of 0.5%.
Received February 25, 2000. Revision May 15, 2000. 相似文献
9.
隐性亮绿作为过氧化物酶催化测定过氧化氢底物的研究 总被引:11,自引:0,他引:11
研究了以隐性亮绿作为氢供体底物的辣根过氧化物酶-过氧化氢催化体系。该体系在PH=6.4-7.5的条件下所形成的亮绿于640nm处有最大吸收。测定过氧化氢的摩尔吸光系数为9.3×10^4L.mol^-1.cm^-1;工作曲线的线性范围为0.036mg/L。方法可应用于雨水中过氧化氢含量的测定。 相似文献
10.
以酚藏花红为指示剂催化荧光法测定痕量亚硝酸根的研究 总被引:18,自引:5,他引:18
基于稀磷酸介质中,亚硝酸根对溴酸钾氧化酚藏花红反应的催化作用,建立了催化荧光法测定痕量亚硝酸根的新方法。反应在55℃水浴中进行8min,线性范围为0.27~7.3μg/L,其回归方程为ΔF=0.40+10.93c,r=0.9994。用于水样中痕量亚硝酸根的测定,结果良好。 相似文献
11.
催化褪色光度法测定痕量铜 总被引:7,自引:0,他引:7
1 引 言催化动力学光度法是一种高灵敏度的分析方法 ,用此方法测定铜已有不少报道。但在pH =1 0的氨性溶液中 ,阳离子表面活性剂氯化十六烷基吡啶 (CPC)存在下 ,Cu2 + 催化H2 O2 对间甲酚紫 (m CP)的褪色反应尚未见报道。研究发现 ,间甲酚紫在pH =1 0的NH3 NH4Cl溶液中呈紫红色 ,再加入阳离子表面活性剂氯化十六烷基吡啶 ,溶液呈蓝紫色 ,Cu2 + 对H2 O2 氧化这种蓝紫色溶液的褪色反应有催化作用 ,从而建立了催化褪色光度法测定铜的新方法。本方法具有灵敏度高 ,操作简便、重现性好、选择性强等优点 ,直接用于人… 相似文献
12.
过氧化氢氧化二甲苯蓝AS催化光度法测定痕量钴的研究 总被引:9,自引:0,他引:9
研究了在碱性条件下,痕量钴(Ⅱ) 与三乙醇胺协同催化H2O2氧化二甲苯蓝AS指示反应的动力学行为,建立了测定痕量钴的新催化动力学分析法。质量浓度的线性范围为0~2.9 μg/25 m L,检出限为1.3×10- 7 g/L。讨论了催化反应机理,测定了茶叶、人发等样品中钴的含量。 相似文献
13.
Ashraf A. Mohamed 《Monatshefte für Chemie / Chemical Monthly》2001,56(2):919-928
A new selective, sensitive, and simple kinetic method is developed for the determination of trace amounts of iodide. The method is based on the catalytic effect of iodide on the reaction of triflupromazine (TFP) with H2O2. The reaction is followed spectrophotometrically by tracing the oxidation product at 498 nm within 1 min after addition of H2O2. The optimum reaction conditions are TFP (0.4 × 10−3 M), H2SO4 (1.0M), H3PO4 (2.0M), and H2O2 (1.6M) at 30°C. Following this procedure, iodide can be determined with a linear calibration graph up to 4.5 ng ċ cm−3 and a detection limit of 0.04 ng ċ cm−3, based on the 3 Sb criterion. The method can also be applied to the determination of iodate and periodate ions. Determination of as little as 0.2, 1.0, 2.0, and 4.0 ng ċ cm−3 of I−, IO3 -, or IO4 - in aqueous solutions gave an average recovery of 98% with relative standard deviations below 1.6% (n = 5). The method was applied to the determination of iodide in Nile river water and ground waters as well as in various food samples after alkaline ashing treatment. The method is compared with other catalytic spectrophotometric procedures for iodide determination. 相似文献
14.
报道了有机化合物极谱催化波的一种新类型--缔合/平行催化氢波.研究麦迪霉素-H2O2体系缔合/平行催化氢波的结果表明,质子化麦迪霉素与H2O2形成缔合物,引起峰电位负移;麦迪霉素催化氢波被H2O2还原中间产物羟基自由基进一步催化,使峰电流显著增加.求得麦迪霉素-H2O2缔合物的缔合比为1:1,表观缔合常数为7.18.在0.15 mol·L-1 KH2PO4-NaOH (pH 7.4)-0.02 mol·L-1 H2O2支持电解质中,-1.59 V (vs. SCE)处的缔合/平行催化氢波二阶导数峰峰电流与麦迪霉素浓度在2.0×10-8~1.0×10-5 mol·L-1范围内呈线性关系,检测限为6×10-9 mol·L-1.与麦迪霉素的催化氢波相比,该缔合/平行催化氢波提高分析灵敏度两个数量级. 相似文献
15.
16.
Ashraf A. Mohamed 《Monatshefte für Chemie / Chemical Monthly》2001,132(8):919-928
Summary. A new selective, sensitive, and simple kinetic method is developed for the determination of trace amounts of iodide. The
method is based on the catalytic effect of iodide on the reaction of triflupromazine (TFP) with H2O2. The reaction is followed spectrophotometrically by tracing the oxidation product at 498 nm within 1 min after addition of
H2O2. The optimum reaction conditions are TFP (0.4 × 10−3
M), H2SO4 (1.0M), H3PO4 (2.0M), and H2O2 (1.6M) at 30°C. Following this procedure, iodide can be determined with a linear calibration graph up to 4.5 ng ċ cm−3 and a detection limit of 0.04 ng ċ cm−3, based on the 3 Sb criterion. The method can also be applied to the determination of iodate and periodate ions. Determination of as little as
0.2, 1.0, 2.0, and 4.0 ng ċ cm−3 of I−, IO3
-, or IO4
- in aqueous solutions gave an average recovery of 98% with relative standard deviations below 1.6% (n = 5). The method was applied to the determination of iodide in Nile river water and ground waters as well as in various food
samples after alkaline ashing treatment. The method is compared with other catalytic spectrophotometric procedures for iodide
determination.
Received January 19, 2001. Accepted (revised) March 12, 2001 相似文献
17.
过氧化氢-偶氮胭脂红B新体系催化光度法测定痕量钼 总被引:6,自引:0,他引:6
1 引言钼的测定常用催化极谱法和硫氰酸盐比色法.基于Na_2CO_3-NaHCO_3介质中,痕量Mo(Ⅵ)对过氧化氢氧化偶氮胭脂红B的褪色反应的强烈催化作用所建立的催化光度新方法用于豆中痕量钼的测定,获得满意结果.2 实验部分2.1 主要仪器和试剂 722型分光光度计(上海第三分析仪器厂).钼标准溶液用钼酸铵配制,Mo(Ⅵ)工作浓浓度为0.1mg/L;Na_2CO_3-NaHCO_3缓冲溶液:0.5mol/L;偶氮胭脂红B:5×10~(-4)mol/L;过氧化氢:15%.所用试剂均为分析纯,实验用水为二次亚沸高纯水. 相似文献
18.
催化过氧化氢氧化铬黑T褪色光度法测定痕量锰(Ⅱ) 总被引:3,自引:0,他引:3
朱国辉 《分析测试技术与仪器》2002,8(4):226-228
在pH11.0的Na2B4O7-NaOH缓冲溶液中十二烷基磺酸钠(DBS)可增敏Mn(II)催化过氧化氢氧化铬黑T(EBT)的褪色反应,据此建立了催化褪色光度法测定痕量锰(Ⅱ)的新方法,锰(Ⅱ)浓度在5.0-12.0ug/L范围内服从比耳定律,回归方程ΔA=-0.014 0.32CMn(Ⅱ)(μg/L),r=0.9999检出限0.5ng/mL,应用该法测定人发和茶叶中的Mn(Ⅱ),测定结果满意。 相似文献
19.
20.
Various mimetic enzyme have been used as catalyst instead of peroxidase in determination of hydrogen peroxide based on the reaction. 相似文献