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.

Study on Chemiluminescence Reactions of L ucigenin and Reductants by Flow Injection Analysis

The chemiluminescence reactions between lucigenin and reductants such as Mo(LII),V( II), U(III), W(III), Cr(II), Ti(III) and Fe( II), which were produced on-line by passing Mo(VI),V(V),U(VI), W(VI), Cr(VI,III),Ti(IV) and Fe(III) through a micro Jones column, are studied in detail. Results show that the reactions can be used directly for the determination of these substances. The mechanism of the reactions is also investigated.

SELECTIVE SULFUR DIOXIDE DETERMINATION BY GAS DIFFUSION FLOW INJECTION ANALYSIS WITH CHEMILUMINESCENT DETECTION

Sulfur dioxide has been found to decrease the chemiluminescence of luminol-iodine system.A new determination method for sulfur dioxide in atmosphere is developed by applying this reaction to a flow injection gas diffusion separation system.This permits the determination of sulfur dioxide selectively and rapidly.

Determination of ribavirin by flow injection chemiluminescence

Objective： To establish a rapid and precise continuous flow-injection chemiluminescence （CL） method to determine ribavirin. Methods： The ribavirin could restrain strongly CL reaction of luminol in sodium hydroxide （NaOH） solution with potassium chlorate （KClO3）. The different experimental parameters affecting the CL intensity were studied carefully. Results： Under optimum conditions （The concentrations of luminol, KClO3, and NaOH were at 0.1 mmol/L, 0.5μmol/L, and 0.2 mol/L, respectively）, the linear range of the working curves was 0.01-7.00μg/ml with a detection limit of 0.004μg/ml. Conclusion： The method is simple, rapid and sensitive, and successfully applied to the determination of ribavirin in pharmaceutical preparations and biological fluids.

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.

Chemiluminescent Determination of Cyromazine in Milk Samples Using Copper（III） Chelate-Triton X-100 by Flow Injection Analysis

Cyromazine（CYR） was determined in milk samples using copper（HI） chelate-Triton X-100 chemiluminescence（CL） system associated with flow-injection（FI） in KOH medium. The relative CL intensity for CYR concentration was linear over the range of 5×10^-4-10μg/mL（R2=0.9990, n=11） with injection rate of 160 h-1 and the relative standard deviation（RSD, n=4） of 1.2%-2.6%. The limit of detection（LOD） for signal-to-noise ratio of 3 was 1.5×10^4μg/mL. The influences of key chemical and physical parameters, some major fresh water ions at their maximum admissible concentrations and a number of pesticides were examined as potential interferences. The concentrations of CYR in spiked milk samples were successfully determined by the proposed method and the results were in good agreement with that of the previously reported HPLC method, having recovery range of （92% a=4%）-（106% a：2%）. The possible CL reaction mechanism for copper（m） chelate-Triton X-100-CYR was also briefly discussed.

Study on Chemiluminescence Reaction between Lucigenin and Four Rare Metal Ions

The chemiluminescence (CL) reactions between lucigenin and four rare metal reductants were studied systematically using a flow injection system.The results show that the reactions can be used for determination of rare metals.The probable mechanism of the CL reactions involves the reduction of dissolved oxygen to the superoxide radical O - 2·by the reductant,followed by the O - 2·reacting with alkaline Lu to generate CL.The pathway involves a dioxetane intermediate.

Flow Injection Chemiluminescence Method for Nalbuphine Hydrochloride in Pharmaceutical Formulations Using Tris(2,2′-bipyridyl)ruthenium(II)Chloride-diperiodatocuprate(III)Reaction

A sensitive and selective method employing chemiluminescence(CL)coupled with flow injection(FI)is reported for nalbuphine hydrochloride(NAL)assay in pharmaceutical formulations.The enhancement effect of NAL on the CL reaction between tris(2,2′-bipyridyl)ruthenium(II)chloride-diperiodatocuprate(III){Ru[(bpy)_(3)]^(2+)-Cu(III)complex}in acidic medium is used as analytical measurement.The optimal conditions of the CL reaction were sulfuric acid 1.0×10^(−3) mol/L,Ru[(bpy)s]2+7.5×10^(−5) mol/L,Cu(III)/Ag(III)complexes 4.0×10^(−4)/5.0×10^(−4) mol/L,sample loop volume of 120µL and flow rate of 2.5 mL/min.The sensitivities of the method in terms of detection(S/N=3)and quantification(S/N=10)limits are 5×10^(−4) and 0.001 ppm(1 ppm=1 mg/L),respectively.The linear response of the instrument in the form of CL intensity with respect to NAL concentration is over the range 0.001-15.0 ppm(R^(2)=0.9999)with relative standard deviation from 0.8%to 3.2%and injection throughput of 120 injection/h.The applications of the method include the quantitative analysis of NAL in pharmaceutical injection samples.Variations and the average results of the proposed method are not significantly different from the results of a reported method by applying F-and paired student t-test.The most likely CL reaction mechanism is written in accordance with spectrophotometric and CL studies.

Chemiluminescence Determination of Molybdenum by on-Line Reduction with a Flow Injection System

The chemiluminescence (CL) reaction between lucigenin (Lu) and molybdenum (III) produced by a Jones reductor was investigated using a flow injection system. On the basis of this, a novel method for the determination of trace amount of molybdenum has been established. The emission intensity was linear with molybdenum concentration in the range of 0.1-1000 ng/mL; the detection limit was 0.02 ng/mL molybdenum; the relative standard deviation was less than 2% for the determination of 0.1 ng/mL molybdenum (n=11). The method has been applied successfully to the analysis of trace molybdenum in water and steel samples.

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.

Electrogeneration of ferrate (Ⅵ) in low concentration NaOH solution for flow-injection-chemiluminescence detection

The possibility of direct analytical applications of ferrate（Ⅵ） solution,which was freshly electrogenerated in low-concentration NaOH electrolyte,was studied by a flow-injection-chemiluminescence（FI-CL） system.It was found that some inorganic ions, organic molecule and biomolecule could enhance the chemiluminescence emission caused by ferrate（Ⅵ）-luminol reaction.V（Ⅴ）, Ca（Ⅱ）,Mg（Ⅱ）,phloroglucinol,and bovine hemoglobin（Hb） chosen as samples were successfully detected by this developed method.The analytical characteristics of the system for the analytes determination including linear ranges,correlation coefficients, limits of detection combined with FI analysis were studied.

Flow Injection Determination of Tramadol Based on Its Sensitizing Effect on the Chemiluminescent Reaction of Permanganate-Sulfite

In this paper, a novel chemiluminescence (CL) method for the determination of tramadol has been developed by combining the flow injection technique and its sensitizing effect on the weak CL reaction between sulfite and acidic KMnO4. A mechanism for the CL reaction has been proposed on the basis of fluorescent and CL spectra. Under the optimized conditions, the proposed method allows the measurement of tramadol hydrochloride over the range of 0.04 - 4 ?g/mLwith a correlation coefficient of 0.9995 (n = 8) and a detection limit of 0.01 ?g/mL (3σ), and the relative standard deviation for 2.0 ?g/mL tramadol (n = 11) is 2.1%. The utility of this method was demonstrated by determining tramadol hydrochloride in tablets and injections.

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).

A Study on the Interaction of the DAS-K with Bovine Serum Albumin by On-line Ultrafiltration and Chemiluminescence

Potassium dehydroandrographolide succinate （DAS-K） has antibacterial and antiviral effects. It has been used widely for the treatment of virus pneumonia, malaria and respiratory infections. In this work, a novel flow-injection chemiluminescence （CL） method for the determination of DAS-K was proposed. The method is based on the reaction between DAS-K and hexacyanoferrate（III） in alkaline solution to give weak CL signal, which is enhanced by rhodamine B. The experimental conditions for the CL reaction were optimized and the possible reaction mechanism was discussed. Under the optimum conditions, the concentration of DAS-K is proportional to the CL intensity in the range of 0.1-80 μmol·L^-1 with a detection limit of 0.05 μmol·L^-1. The interaction of the DAS-K with bovine serum albumin by on-line ultrafiltration and flow-injection chemiluminescence was studied. The concentrations of unbound DAS-K from ultra filter tube were determined by the flow-injection CL method. The binding parameters were estimated by the Scatchard plot and Klotz plot. The proposed system proved that FIA-CL coupled with on-line ultrafiltration sampling was a fast and simple technique for the study of drug-protein interaction.

邻菲啰啉-H_2O_2-Sn(Ⅳ)化学发光体系的研究

测定痕量锡可采用分光光度法、荧光分析法等。目前,高灵敏度的化学发光分析法已用于多种金属离子的分析,但是,锡的化学发光分析尚未见报道。本文采用的反相流动注射化学发光分析(rFIA-CL)法是以试样作载流,定量注入试剂到试液流中的一种分析新技术。rFIA法能在一定程度上克服基线漂移,提高分析灵敏度,减少试剂消耗,且重现性好。我们观察到邻菲啰啉(phen)在碱性介质中被H_2O_2氧化时有较强的化学发光,痕量Sn(Ⅳ)

光泽精─H_2O_2─Sn（Ⅳ）化学发光体系的研究及应用

利用反相流动注射系统，对光泽精－Ｈ２Ｏ２－Ｓｎ（Ⅳ）化学发光新体系进行了研究。考察了测定锡的最佳条件，在选定条件下测定Ｓｎ（Ⅳ）的线性响应浓度为３０×１０－９～９．０×１０－６ｇ／ｍｌ，方法灵敏度较高，检测下限达２５ｎｇ／ｍｌ，对含５．５×１０－７ｇ／ｍｌＳｎ（Ⅳ），ｎ＝１１，ＲＳＤ为３．７％，本法用于沉积物标样中锡的测定，其结果与推荐值吻合。

碳点增敏的流动注射化学发光法测定食品中二氧化硫的含量

二氧化硫的检测对于食品安全保障具有重要意义。采用酸性高锰酸钾-亚硫酸盐化学发光体系,以碳点(Carbon Dots,CDs)为增敏剂,结合流动注射技术(Flow Injection Analysis,FIA)建立了一种用于检测食品中二氧化硫含量的简便方法。在优化的实验条件下,该方法的线性范围为1.0×10^(-5)–3.0×10^(-4) mol·L^(-1),检出限为7.79×10^(-6) mol·L^(-1)。该实验适合作为本科生仪器分析课程的教学实验,帮助学生掌握化学发光、流动注射分析技术的原理及应用,学习科学研究的基本方法,提高思考能力。

流动注射化学发光法测定双嘧达莫

采用流动注射技术研究了酸性条件下，双嘧达莫与高锰酸钾和过氧化氢的化学发光行为，对影响化学发光强度的诸因素进行了实验和探讨，建立了流动注射化学发光法测定双嘧达莫的新方法。方法的检出限为5．8×10-8g／mL，线性范围为2×10-7～8×10-5g／mL，对4×10-6g/mL双嘧达莫进行了11次平行测定，相对标准偏差为1．4％。方法用于药剂中双嘧达莫含量的测定，结果与药典标准法测得值一致。

用偶合反应-流动注射化学发光法测定食品和水中痕量亚硝酸根

基于在酸性介质下，ＮＯ２－与Ｉ－快速反应产生Ｉ２，和Ｉ２氧化Ｌｕｍｉｎｏｌ产生化学发光反应，建立了Ｌｕｍｉｎｏｌ－Ｉ－－ＮＯ２－偶合发光体系测定痕量 ＮＯ２－的方法。本法测定 ＮＯ２－线性范围：８．０×１０－９～１．０×１０－６ｇ／ｍＬ；检出限１．６×１０－９ｇ／ｍＬ；对１．０×１０－８ｇ／ｍＬＮＯ２连续１１次测定的相对标准偏差为１．５％。用于食品及水中亚硝酸根的测定，结果满意。

锰C-抗坏血酸甲醛-化学发光体系的研究

实验观察到锰 氧化抗坏血酸可以产生弱的化学发光 ,甲醛对这一化学发光反应有较强的增敏作用 ,据此建立了测定抗坏血酸的流动注射化学发光分析法。方法的检出限为 2× 1 0 -8mol/L抗坏血酸 ;线性响应范围为 6 .0× 1 0 -8～ 2 .0× 1 0 -5mol/L。对 1 .0× 1 0 -6mol/L的抗坏血酸进行 1 1次测定 ,相对标准偏差为 2 3%。该方法已成功应用于维生素C针剂和片剂中抗坏血酸含量的测定 。