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催化动力学光度法测定水中痕量锰 总被引:7,自引:0,他引:7
报道[1,2],但以高碘酸钾氧化胭脂红作为指示反应的方法还未见报道。本文研究发现,在氨水 NH4Cl介质中,锰能强烈催化高碘酸钾氧化食用色素胭脂红的褪色反应,在510nm波长处,其反应速度lg(A0/A)与锰的浓度之间符合动力学一级反应关系式:lg(A0/A)=KCMn,由此建立了一个高灵敏、高选择性的测定痕量锰的方法。该法检出限为8×10-9g·L-1,线性范围在0~5.0μg/25ml。用于水样中的痕量锰的测定,结果满意。1 试验部分1.1 主要仪器与试剂753B型分光光度计(上海分析仪器厂)锰标准溶液:1.0mg·ml-1,使用时稀释成1 0μg·ml-1。高碘酸钾溶液:0.01mo… 相似文献
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高灵敏催化光度法测定痕量锰 总被引:12,自引:1,他引:11
刘长增 《理化检验(化学分册)》2001,37(8):369-371
研究了痕量Mn2 + 催化KIO4 氧化棉红的反应动力学 ,测定了反应级数、表观速率常数和表观活化能 ,确立了速率方程 ,探讨了反应机理 ,建立了测定痕量锰的方法 ,方法灵敏度为 7.5×10 - 9g·L- 1,线性范围为 0 .0~ 6.0× 10 - 6g·L- 1。方法选择性好 ,直接用于化学试剂、井水及蒸馏水中痕量锰的测定 ,结果满意 相似文献
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高碘酸钾-二安替比林对碘苯基甲烷体系催化光度法测定痕量钌(Ⅲ) 总被引:2,自引:0,他引:2
合成了新试剂二安替比林对碘苯基甲烷(DApIM),研究了在磷酸介质中钌(Ⅲ)催化高 碘酸钾氧化DApIM的显色反应,建立了一种测定痕量钉的催化光度分析法。方法的线性范 围为 0~6 μg/L;检测限为1.6 × 10-7g/L。该体系灵敏度高,稳定性好,用于矿样中痕量钉的 测定,其相对标准偏差为3.0%~4.1%,标准加入回收率为97%105%。 相似文献
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偶氮羧Ⅰ催化动力学光度法测定痕量铬的研究 总被引:6,自引:1,他引:6
研究了痕量铬(Ⅵ)对高碘酸钾氧化偶氮羧Ⅰ反应的催化作用,发现其在硝酸介质中具有高灵敏的反应,检出限为8.2×10-10g·ml-1,线性范围为0~0.08μg·ml-1。可用于测定水样中的铬。 相似文献
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基于肾上腺素对血红蛋白酶催化体系的抑制作用, 建立了酶催化动力学光度法测定肾上腺素的新方法. 实验研究了体系的最佳条件及动力学行为, 测定的线性范围为4.5×10-7~1.4×10-5 mol/L, 方法检出限为5.2×10-8 mol/L. 对浓度为9.0×10-6 mol/L的肾上腺素进行11次平行测定的相对标准偏差为3.5%. 此方法可用于药剂中肾上腺素含量的测定. 相似文献
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Based on catalysis of I- on the decolor reaction between potassium bromate and indigo carmine in the acid medium,and combined with flow injection analysis,a new flow-injection catalytic kinetic spectrophotometric method was found for determination of iodide in sample.The experimental results show that the determination is carried out at temperature of 80℃ and the concentration of H_2SO_4,KBrO_3,and indigo carmine is 1.2 mol/L,1.8×10~(-2) mol/L and 1.0×10~(-4) mol/L respectively,the linear range for the method is 0.50~1.8 mg/L.The detection limit is 0.0022 mg/L.The relative standard deviation is 1.92%.The proposed method was applied to the determination of iodide in troche successfully.The recovery was between 99.2% and 103.6%. 相似文献
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催化动力学测定痕量对苯二酚 总被引:2,自引:0,他引:2
研究了在pH7.3的KH2PO4 Na2HPO4缓冲介质中,痕量对苯二酚催化高碘酸钾氧化靛红褪色的新指示反应及其动力学条件,建立了动力学光度法测定痕量对苯二酚的新方法。该方法检出限为6.8×10-6g L,线性范围是0.04~0 18μg mL和0.28~0.54μg mL。可用于显影废液中对苯二酚的测定。 相似文献
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Di-cysteine substituted hypocrellin B (DCHB) is a new water-soluble photosensitizer with significantly enhanced red absorption at wavelengths longer than 600 nm over the parent compound hypocrellin B (HB). The photosensitizing properties (Type I and/or Type II mechanisms) of DCHB have been investigated in dimethylsulfoxide (DMSO) and aqueous solution (pH 7.4) using electron paramagnetic resonance (EPR) and spectrophotometric methods. In anaerobic DMSO solution, the semiquinone anion radical of DCHB (DCHB•−) is predominantly photoproduced via self-electron transfer between excited- and ground-state DCHB species. The presence of an electron donor significantly promotes the formation of the reduced form of DCHB. When a deoxygenated aqueous solution of DCHB and an electron donor are irradiated with 532 nm light, the hydroquinone of DCHB (DCHBH2) is formed via the disproportionation of the first-formed DCHB•− and second electron transfer to DCHB•− from the electron donor. When oxygen is present, singlet oxygen (1O2), superoxide anion radical (O2•−) and hydroxyl radical (•OH) are produced. The quantum yield of 1O2 generation by DCHB photosensitization is estimated to be 0.54 using Rose Bengal as a reference, a little lower than that of HB (0.76). The superoxide anion radical is also significantly enhanced by the presence of electron donors. Moreover, (O2•−) upon disproportionation generated H2O2 and ultimately the highly reactive •OH via the Haber-Weiss reaction pathway. The efficiency of (O2•−) generation by DCHB is obviously enhanced over that of HB. These findings suggest that the photodynamic actions of DCHB may proceed via Type I and Type II mechanisms and that this new photosensitizer retains photosensitizing activity after photodynamic therapy-oriented chemical modification. 相似文献