Study on Quenching Effect of Holmium (Ⅲ) Ion in Chemiluminescence System of Luminol H_2O_2-Cr(Ⅲ) by Flow Injection Technique

A new chemiluminescence (CL) analytical method for determination of rare earth Ho(Ⅲ) ion is reported. It is based on the quenching effect of Ho(Ⅲ) ion on CL intensity of Luminol H 2O 2 Cr(Ⅲ) system. The detection limit is 3×10 -8 mol/L, the linear range is from 1×10 -7 to 1×10 -4 mol/L; the relative standard deviation is less than 3% (for 2×10 -7 mol/L Ho, n=11). The method was applied to determination of Ho(Ⅲ) in pure samples with satisfactory results.

Flow Injection Analysis of Histidine with Enhanced Electrogenerated Chemiluminescence of Luminol

A simple and sensitive flow injection method is presented for the determination of histidine based on its enhancement of electrogenerated chemiluminescence (ECL) of luminol. After optimization of the experimental parameters, the working range for histidine was in 1.0 x 10-6 to 1.0 x 10 -3 mol/L with a detection limit (S/N = 3) of 0.56 mmol/L. The relative standard deviation was 1.6% for 11 measurements of 5 x 10 5 mol/L histidine solution. The proposed method has been successfully applied to the determination of histidine in real pharmaceutical preparation.

Determination of chlorogenic acid by flow injection irreversible biamperometry

A flow injection irreversible biamperometric method for the determination of chlorogenic acid is described. The proposed method is based on the electrochemical oxidation of chlorogenic acid at pretreated platinum electrode and the reduction of permanganate at another electrode to form an irreversible biamperometric detection system. Under the external potential difference （z^v） of 0 V, in the 0.05 mol/L sulfuric acid, chlorogenic acid can be determined over the range 0.8-120 mg/L with a sample measurement frequency of 80 samples/h. The detection limit is 0.18 mg/L. The proposed method exhibits the satisfactory reproducibility with a relative standard derivation （R.S.D.） of 2.21% for 19 successive determinations of 40 mg/L.

Chemiluminescence detection of permanganate index (COD_(Mn)) by a luminol-KMnO_4 based reaction

A novel chemiluminescence （CL） system for determination of permanganate index （CODMn） combined with flow injection analysis has been proposed in this study. On the basis of the chemiluminescent reaction of luminol-KMnO4 system, light emission caused by luminol-KMnO4 system was detected by the photomultiplier tube, and its intensity caused by the appearance of KMnO4 after sample digestion was inversely proportional to CODMn. Effects for CODMn determining such as pH, concentrations and interference were investigated in detail. A detection limit of 0.3 mg/L CODMn with a linear range of 0.3-200 mg/L for its theoretical CODMn was obtained under the optimized experimental conditions. The relative standard deviation was 4.3% for 5.0 mg/L CODMn （n = 11）. This CL flow system for determining CODMn was simple, rapid, and suitable for automatic analysis. The data obtained by the present method were fairly in good agreement with those obtained by the standard titrimetric method. It has been applied to determine real samples with satisfactory results.

Chemiluminescence Behavior of Luminol-KIO₄-Ag Nanoparticles System and Its Analytical Applications

It was found that silver nanoparticles could strongly enhance the chemiluminescence (CL) of the luminol-KIO4 system in the presence of Co2+. The most intensive CL signals were obtained with silver nanoparticles in diameter of 22 nm. The studies of UV-visible spectra and CL spectra were carried out to explore the possible CL enhancement mechanism. Moreover, the influences of 17 amino acids and 25 organic compounds on the luminol-KIO4-Co2+-Ag NPs CL system were studied by a flow injection procedure, which led to an effective method to detect these compounds.

Flow-injection Chemiluminescence Sensor for the Determination of Gallic Acid by Immobilizing Luminol and Periodate on Anion-exchange Resin

A novel chemiluminescence (CL) sensor for the determination of gallic acid combined with flow injection analysis was developed by electrostatically immobilizing luminol and periodate on anion-exchange resins respectively. Gallic acid was sensed by its enhancing effect on the weak CL reaction between luminol and periodate, which were eluted from the ion exchange column. The possible reaction mechanism of the CL system was suggested and discussed. The response of the sensor to gallic acid concentration was linear over the range of 8.0×10 -9-1.0×10 -6 mol/L with a detection limit of 6.5×10 -9 mol/L (3σ). The relative standard deviation (RSD) for 7 repetitive determinations of gallic acid (1.0×10 -7 mol/L) was 1.8%. The sensor could be used for over 400 times determination with a good reproducibility.

Flow Injection Chemiluminescence Determination of 4-methylsalicylic

As potassium bichromate can be reduced by 4-methysalicylic acid to chromium(III) which enhance the CL intensity of luminol-H2O2 system,a new chemiluminescence system for the determination of 4-methysalicylic acid has been established.The relative CL intensity was correlated with salicylic acid concentration in the range 7.0×10-9～8.0×10-6 mol/L,and the detection limit was 1.0×10-9 mol/L.The relative standard deviation(n=8) for 4.0×10-7 mol/L 4-methysalicylic acid is 2.9%.The method has been applied to the determination of 4-methysalicylic acid in the bactericidal solutions with satisfactory results.

Flow-injection Chemiluminescence Determination of Catecholamines

A flow injection chemiluminescence (CL) method for the determination of catecholamines is described which is based on their inhibition of the intensity of CL from the luminol-hypochlorite system The hypochlorite was electrogenerated on-line by a constant current electrolysis, resulting in the elimination of the instability of the hypochlorite solution prepared from a commercial reagent of sodium hypochlorite. The detection limits are 0.6 ng/ml for dopamine, 0.8 ng/ml for adrenaline and isoprenaline. The proposed method has been successfully applied to the determination of catecholamines in pharmaceutical injections.

Luminol-K_3Fe(CN)_6 chemiluminescence system for the determination of glipizide

A rapid and sensitive flow-injection chemiluminescence（CL） method for the determination of glipizide was developed on the basis of finding that glipizide can enhance the CL intensity of the luminol-K3Fe（CN）6 system.In optimum condition,the increased CL intensity was directly proportional to the concentration of glipizide in the range from 4.0×108 g/mL to 1.0×106 g/mL and the detection limit was 1.0×108 g/mL glipizide.The relative standard deviation（RSD） of the developed method was 2.1% with 11 repeated measurements of 1.0×107 g/mL glipizide.The developed method has been successfully applied to the analysis of glipizide in its pharmaceutical preparations.

Chemiluminescence determination of 20 amino acids and the mechanism study

It was found that 20 amino acids could inhibit the intensity of the luminol-H_2O_2-CuSO_4 chemiluminescence system.Using this character,a rapid and sensitive method for the determination of 20 amino acids was developed with flow injection coupled with chemiluminescence detection.Under the optimal conditions,the detection limits of 20 amino acids were in the range of 4.5×10^（-7）- 4.3×10^（-10） mol/L,and the relative standard deviations were less than 3.2%.The proposed method was successfully applied to drug analysis.The possible mechanism was also discussed.

A Novel Enhancer for Fe^(2+)-Catalyzed Light Emission Reaction of Luminol and Dissolved Oxygen

EDTA was used as an enhancer for Fe 2+ catalyzed light emission from luminol oxidation by dissolved oxygen. As a result, the limit of detection for ferrous ion with flow injection analysis was improved by a factor of 160 by addition of EDTA to the luminol solution. Fe 2+ and Fe 3+ were determined simultaneously with a novel copper-coated zinc reductor minicolumn installed in one of the shunt after sample splitting in the manifold. The reductor minicolumn can be used for 3000 determinations at least. The dynamic range of determination was 1×10 -9 ～1×10 -5 mol·L -1 , with the limit of detection of 2.7×10 10 and 3.5×10 10 mol·L 1 ,for Fe 2+ and Fe 3+ , respectively. The preci sion for determination of 2×10 7 mol·L 1 of Fe 2+ and Fe 3+ was 2.3% and 4.0% (n=8), respectively, at a sampling rate of 60 h -1 . Cr 3+ and Co 2+ interfere. Fe 2+ and Fe 3+ in mixture were determined with satisfactory results. Samples of Fe 2+ and Fe 3+ were determined simultaneously and the results in good agreement with the standard spectrophotometric method. Indications were shown that EDTA functions as an enhancer, Fe 2+ as a catalyst, and oxygen is the oxidant of the chemiluminescent reaction, and the mechanism of the reaction was discussed.

Determination of Lanthanu m in Lu minol- H_2 O_2- Cr( Ⅲ) Syste m by Flow Injection Chemilu minescence

A novel method of flow injection chemiluminescence (CL) analysis for the determination of rare earth La(Ⅲ) ion is prensented. It is based on the quenching effect of La(Ⅲ) ion in the CL system of Luminol H 2O 2 Cr(Ⅲ). The CL emission intensity is linear with La(Ⅲ) concentration in the range 1×10 -7 ～1×10 -4 mol/L; the detection limit is 4×10 -8 mol/L, the relative standard deviation is less than 3% (for 2×10 -7 mol/L La, n =11).

流动注射-鲁米诺-KMnO_(4)化学发光抑制法测定鸡蛋中氟苯尼考残留含量

在碱性条件下,基于氟苯尼考会抑制鲁米诺-KMnO4化学发光,并且随着氟苯尼考浓度的增加,其抑制化学发光强度随之增强,从而建立流动注射-鲁米诺-KMnO4化学发光体系检测氟苯尼考的方法。分别探讨试剂用量、蠕动泵流速等参数条件对该发光强度的影响。优化条件下,在1.0×10^(-6)℃~1.0×10^(-4)g·mL^(-1)质量浓度范围内,氟苯尼考质量浓度与相对化学发光强度呈良好的线性关系,方法检出限(3σ)3.0×10^(-7)g·mL^(-1);对质量浓度8.0×10^(-5)g·mL^(-1)的氟苯尼考平行测定11次,RSD为4.88%。结果表明,建立的流动注射-化学发光分析方法简单快速,并将该方法应用于动物源性食品鸡蛋样中兽药氟苯尼考残留的分析,方法灵敏、准确、可靠,结果令人满意。

鲁米诺化学发光抑制法测定阿洛酮糖

建立一种流动注射化学发光测定阿洛酮糖的方法。基于碱性条件下,阿洛酮糖对鲁米诺-H_(2)O_(2)体系的发光强度具有显著的抑制作用,且发光信号的降低值(即相对发光强度)ΔI与阿洛酮糖浓度的对数在一定范围内成线性关系,建立了一种流动注射化学发光法测定阿洛酮糖的新方法。在最佳实验条件下,方法的线性范围为在0.002 mg·mL^(-1)~2.0 mg·mL^(-1)(R=0.9977),方法的检出限为4.3×10^(-4) mg·mL^(-1),对0.05 mg·mL^(-1)的阿洛酮糖连续测定11次,其相对标准偏差为3.1%。该方法用于果冻中阿洛酮糖含量的测定,与高效液相色谱法测得结果基本一致。

流动注射-Luminol/Tween 20化学发光体系测定邻苯二酚

基于邻苯二酚对luminol-Tween 20化学发光体系的强烈的抑制作用,建立了一种简单、灵敏的luminol-Tween 20化学发光体系测定邻苯二酚的新方法。在最佳实验条件下,方法的检出限为5.0×10-10mol/L,线性范围为1.0×10-9mol/L～1.0×10-7mol/L,对5.0×10-8mol/L邻苯二酚进行平行测定11次,其RSD为4.1%。该方法可应用于自来水样中邻苯二酚的测定。

基于流动注射化学发光的两种Luminol体系对重楼药材中总皂苷的分析检测研究

【目的】构建流动注射化学发光的2种Luminol体系检测重楼中总皂苷的含量.【方法】基于Luminol-H_(2)O_(2)和KMnO_(4)-Luminol-H+两种体系能产生化学发光,加入重楼皂苷后可抑制体系的发光强度.因此,构建流动注射化学发光检测重楼中总皂苷的分析方法,同时开展了方法验证和干扰试验,并对两种体系分别进行了流程及条件优化.在优化条件下,Luminol-H_(2)O_(2)和KMnO_(4)-Luminol-H+两种体系的相对发光强度分别与重楼皂苷Ⅶ浓度在一定范围内呈良好线性关系.【结果】该方法的检出限分别为0.2015μg/mL和0.1021μg/mL,平均回收率分别为99.96%和97.23%;检测样品中重楼总皂苷平均得率分别为21.138 mg/g和21.317 mg/g.【结论】所构建的两种化学发光体系,其线性检测范围宽、检出限低、精密度好,可用于重楼药材的品质分析和含量检测.

稀土Yb(Ⅲ)对Luminol-H_2_O2-Cr(Ⅲ)体系的化学发光熄灭效应

研究了稀土Ｙｂ（Ⅲ）对Ｌｕｍｉｎｏｌ－Ｈ２Ｏ２－Ｃｒ（Ⅲ）体系化学发光的熄灭效应，在此基础上建立了稀土Ｙｂ的流动注射化学发光分析法。该法灵敏度高，线性范围宽，仪器设备简单。

Luminol-Cu^(2+)体系流动注射化学发光法测定头孢拉定

在Cu(Ⅱ)存在条件下,头孢拉定与鲁米诺在碱性溶液中产生强的化学发光反应。基于此提出了一种流动注射化学发光法测定头孢拉定的新方法。在优化的实验条件下,该方法的线性范围为1.0-10-9~1.0-10-7g/mL,检出限为3-10-10 g/mL。相对标准偏差为1.0%(1.0-10-8 g/mL头孢拉定,n=11)。该方法已用于药物制剂中头孢拉定含量的测定,并探讨可能的反应机理。

Luminol-K_3[Fe(CN)_6]流动注射化学发光体系检测头孢吡肟

在碱性介质中,头孢吡肟对Luminol-K3[Fe（CN）6]化学发光体系具有明显的增强作用,基于此建立了流动注射化学发光法测定头孢吡肟的新方法。在优化实验条件下,化学发光增强强度与头孢吡肟的浓度在3.0×10-6~4.0×10-5g/m L范围内呈良好的线性关系,检出限为2.8×10-6g/m L。对2.0×10-5g/m L头孢吡肟平行测定11次,相对标准偏差（RSD）为1.5%。该方法用于头孢吡肟针剂的测定,结果满意。

luminol-H_2O_2-NaOH化学发光体系测定氯氮卓的含量

研究了氯氮卓在luminol-H2O2-NaOH体系中的化学发光行为，在选定的最佳实验条件下，测定了氯氮卓浓度与化学发光强度的关系。结果表明：在1．11×10^-11～8．35×10^-10mol／L内氯氮卓浓度与发光信号成线性关系，检出限为4．79×10^-12mol／L，重复测定11次的相对标准偏差为2．49％（Cs=3．34×10^-10mol／L）。该方法被成功用于梨汁中氯氮卓含量的分析，该方法简单、快速、灵敏度高，对法院毒物检测具有重大现实意义。