A simple and rapid flow injection chemiluminescence determination of cysteine with Ru(phen)3(2+)-Ce(IV) system

A new chemiluminescence system was developed for the determination of cysteine by flow injection system. This method is based on the reaction of L-cysteine with Ru(phen)3(2+) and Ce(IV) to produce chemiluminescence. The calibration curve was linear over the range 8.0x10(-7) to 4.0x10(-5) and 4.0x10(-5) to 1.0x10(-3) M with a detection limit of 7.0x10(-7) M (S/N=3). The relative standard deviation of 4.0x10(-6) M cysteine was found 3.5% (n=10). The influence of potential interfering substances was studied. The proposed method was successfully applied for the flow injection determination of cysteine in the real samples with minimum sampling rate of 90 sample/h.     

High selective determination iron(II) by its enhancement effect on the fluorescence of pyrene-tetramethylpiperidinyl (TEMPO) as a spin fluorescence probe

A novel fluorescence method determination for iron(II) with a high selectivity and sensitivity has been proposed, based on the enhancement of fluorescence signals resulting from specific redox reaction between synthesized spin fluorescence probe pyrene-tetramethylpiperidinyl (TEMPO) and iron(II). Under the experimental conditions, fluorescent probe displayed a rapid and linear response for iron(II) over the concentration range from 2.4 x 10(-7) to 3.6 x 10(-6) mol/L. The limit of detection was 4.0 x 10(-8) mol/L. The relative standard deviation of six replicate measurements was 1.90% for 3.0 x 10(-7) mol/L iron(II). Because of the specific redox reaction between developed spin fluorescence probe and iron(II), there are few interference by other ions, especially in the presence of relative high concentration iron(III). The method has been successfully applied for iron(II) determinations in two different kinds of real samples. Results determined by the proposed method agree favorably with those determined UV-vis spectrometry method with 1,10-phenanthroline.     

L-酪氨酸-高锰酸钾-硫酸化学发光体系研究

在硫酸介质中 ,L -酪氨酸与高锰酸钾反应能产生较强的化学发光 ,据此建立了测定 L -酪氨酸的分析方法。该法线性范围为 4.0× 1 0 - 6 ～ 2 .8× 1 0 - 5mol/L;检出限为 8.8× 1 0 - 7mol/L;对 1 .0× 1 0 - 5mol/L 的 L-酪氨酸进行连续1 0次平行测定 ,相对标准偏差为 2 .7%。该法已应用于测定医用氨基酸注射液中的 L-酪氨酸。     

Synthesis of a novel chemiluminescent reagent for the determination of hydrogen peroxide in snow waters

7-(4,6-Dichloro-1,3,5-triazinylamino)-4-methylcoumarin (DTMC) was synthesized as a completely new chemiluminescent reagent, and with it a novel chemiluminescence method was developed for the determination of hydrogen peroxide in the absence of any added catalyst or co-oxidant. The chemiluminescence intensity of the DTMC-H(2)O(2) system could be enhanced by the addition of cation surfactants. The chemiluminescence intensity was directly proportional to the concentration of H(2)O(2) in the range 1.0 x 10(-7)-4.0x10(-4) mol l(-1), and the detection limit was 4.0 x 10(-8) mol l(-1). The relative S.D. was 4.9% for 1.0 x 10(-6) mol l(-1) of H(2)O(2) (n=10). The selectivity of this method was high, and most of the transition metal ions have no effect on the determination. The proposed method has been applied to the determination of trace amounts of hydrogen peroxide in snow water. A possible mechanism of the chemiluminescence reaction is also discussed.     

基于纳米TiO2的化学发光法检测铁(Ⅱ)

铁(Ⅱ)能在具有催化活性的纳米TiO2表面产生化学发光辐射,表面活性剂十六烷基三甲基溴化铵(CTAB)的存在能显著增敏此发光强度。此外,纳米氧化钛也能增强Fenton反应的化学发光强度,据此,建立了纳米TiO2-CTAB-Fenton化学发光新体系检测铁(Ⅱ)的新方法。在优化条件下,亚铁离子在1.0×10-8~1.0×10-6mol/L浓度范围内与其化学发光强度呈现良好的线性关系,对1.0×10-7mol/L浓度的亚铁离子平行测定5次,相对标准偏差为3.9%,检出限为4.0×10-9mol/L。文中还对化学发光反应机理进行了初步探讨。     

Tris(2,2'-bipyridine)ruthenium(II) electrogenerated chemiluminescence of alkaloid type drugs with solid phase extraction sample preparation

An electrogenerated chemiluminescence (ECL) method for the determination of pethidine, atropine, homatropine and cocaine is described. The optimum conditions were found to be similar for all of these compounds although the ECL emission intensity for cocaine was an order of magnitude lower than for pethidine due to their different chemical structures. Linear calibrations were obtained for all the compounds at pH 10 in borate buffer (0.05 mol l-1) at 1.3 V. Limits of detection of 6.8 x 10(-8), 2.2 x 10(-7), 3.2 x 10(-7) and 6.5 x 10(-7) mol l-1, respectively, were achieved for pethidine, atropine, homatropine and cocaine in standard solutions. Solid-phase extraction was used to separate the drugs from their matrix and the method was applied to the determination of spiked urine samples. The limits of quantitation for pethidine, atropine, homatropine and cocaine in urine were 1.0 x 10(-6), 2.0 x 10(-6), 2.0 x 10(-6) and 4.0 x 10(-6) mol l-1, respectively, with recoveries of between 90 and 110%.     

A simple and rapid flow-injection chemiluminescence method for the determination of noscapine with Ru(phen)3(2+)-Ce(IV) system

A new flow injection chemiluminescence (CL) system was used for the determination of noscapine. This technique is based on the reduction effect of noscapine on the Ru(phen)3(3+), which is produced by reaction between Ru(phen)3(2+) and acidic Ce(IV) solutions, and this rapid reduction produces strong CL. Calibration plots were linear over the range of 3.0 x 10(-7) - 2.0 x 10(-6) mol L(-1) and 2.0 x 10(-6) - 2.0 x 10(-4) mol L(-1). The CL intensity was so high, that it is able to produce a detection limit of 6.6 x 10(-8) M noscapine (3sigma). The relative standard deviation of 2.0 x 10(-6) M noscapine was 1.0% (n=10). The proposed method was successfully applied for the flow injection determination of noscapine in cough and Tonin syrup samples. The results of real sample analyses show good recovery percentages (97.3-102.4%). The minimum sampling rate was 100 samples per hour.     

Chemiluminescence of tryptophan and histidine in Ru(bpy)3(2+)-KMnO4 aqueous solution

Amino acids with different chemical structures have different abilities in terms of increasing the intensity of chemiluminescence (CL) of tris(2,2'-bipyridine)ruthenium(II) [Ru(bpy)3(2+)]. In a flow system, CL caused by the reaction between Ru(bpy)3(3+) and 15 amino acids was observed, but only tryptophan (Trp) and histidine (His) enhanced the intensity obviously, and so the CL of Trp and His and their molecular groups was studied. A calculation of the ionization potentials (IPs) of their N atom indicated that the CL intensities of these compounds depended on their IPs. In addition, the flow system was used for the determination of Trp and His, and the detection limits were 3 x 10(-8) mol L(-1) for His and 2.5 x 10(-9) mol L(-1) for Trp. The calibration curves for the two amino acids were 1.0 x 10(-7) to 5.0 x 10(-3) mol L(-1) for His and 1.0 x 10(-8) to 1.0 x 10(-4) mol L(-1) for Trp. The proposed approach was applied to the determination of His in Ganoderma.     

Flow-injection chemiluminescence determination of chlorinated isocyanuric acids

A rapid and sensitive flow-injection chemiluminescence method is described for the determination of dichloro- and trichloroisocyanuric acids based on the chemiluminescence produced during their reaction with luminol in alkaline medium. The effects of analytical and flow-injection variables on these chemiluminescence systems and determination of both oxidants are discussed. The optimized method yielded 3sigma detection limits of 8x10(-8) and 5x10(-8) mol L(-1) for the sodium dichloroisocyanurate and trichloroisocyanuric acid, respectively. The optimum conditions were found to be as follows: NaOH, 1x10(-1) mol L(-1); luminol, 5x10(-3) mol L(-1); KI, 2x10(-3) mol L(-1) and flow rate, 3.5 mL min(-1).     

Flow-injection electrogenerated chemiluminescence determination of isoniazid using luminol.

Based on a new electrogenerated chemiluminescence (ECL) analytical idea, this paper explains a sensitive and selective flow-injection ECL method using luminol for the determination of isoniazid, based on the sensitizing effect of isoniazid for the weak ECL emission of electrochemically oxidized luminol. Under the optimum experimental conditions, the relative ECL intensity was linear with isoniazid concentration in the range of 4.0 x 10(-8) mol/L to 8.0 x 10(-6) mol/L and with a detecting limit of 2.8 x 10(-8) mol/L.     

流动注射-抑制化学发光法测定镱(Ⅲ)

在碱性介质中, Yb(Ⅲ)对Luminol-KMnO4体系化学发光强度具有抑制作用, 据此建立了一种测定Yb(Ⅲ)的化学发光新方法. 在优化的实验条件下, 化学发光强度与Yb(Ⅲ)的浓度在4.0×10-7～1.0×10-4 mol/L范围内呈现出良好的线性关系. 其检测限(3σ)为5.0×10-8 mol/L, 对8.0×10-5 mol/L的Yb(Ⅲ)溶液进行测定, 相对标准偏差为3.9% (n=11). 本法已应用于合成样品中的镱的测定.     

Direct determination of amino acids by pressurized capillary electrochromatography with chemiluminescence detection

A pressurized CEC (pCEC) coupled with on-column chemiluminescence (CL) detection was developed for direct determination of amino acids, which was based on the principle of an enhanced effect of Cu(II)-amino acid complexes on the CL reaction between luminol and hydrogen peroxide in alkaline solution. The effects of some important factors on pCEC separation and CL intensity were systemically investigated. Baseline separation of amino acids including L-histidine (L-His), L-threonine (L-Thr), and L-tyrosine (L-Tyr) was achieved by using a monolithic column with a mobile phase of 5.0x10(-3) mol/L phosphate buffer at pH 8.0 that contained 25% v/v methanol and 5.0x10(-4) mol/L luminol and 1.0x10(-5) mol/L Cu(II) at an applied voltage of -5 kV. The calibration curves of the analytes by plotting the peak height against corresponding concentration were linear over the range of 3.2x10(-6)-3.2x10(-4) mol/L for L-His, 4.1x10(-6)-4.1x10(-4) mol/L for L-Thr, and 6.0x10(-7)-3.0x10(-4) mol/L for L-Tyr. The LODs for L-His, L-Thr, and L-Tyr were 6.4x10(-7), 8.4x10(-7), and 3.0x10(-7) mol/L (S/N = 2), respectively. The proposed method was applied to the analysis of amino acid injection sample with satisfactory results. Mean recoveries for three amino acids were from 84.3 to 89.6%.     

Determination of Genistein by Flow‐injection Chemiluminescence Method Based on Ferricyanide Oxidation Sensitized by Rhodamine 6G

A novel flow injection chemiluminescence (FI‐CL) method for the determination of genistein was described. The method was based on the reaction between genistein and potassium ferricyanide in alkaline solution to give weak CL signal, which was dramatically enhanced by rhodamine 6G (Rh G). The CL emission allowed quantitation of genistein concentration in the range 1.0 × 10^?7–4.0 × 10^?5 mol/L with a detection limit (3σ) of 4.2 × 10^?8 mol/L. The relative standard deviation for 11 parallel measurements of 5.0 × 10^?7 mol/L, 4.0 × 10^?6 mol/L and 1.0 × 10^?5 mol/L genistein were 2.59%, 2.40% and 1.48%, respectively. The experimental conditions for the CL reaction were optimized and the possible reaction mechanism was discussed. The method was applied to the determination of genistein in biological fluids.     

Amperometric determination of glutathione and cysteine on a Pd-IrO(2) modified electrode with high performance liquid chromatography in rat brain microdialysate

A Pd/IrO(2) co-electrodeposited glassy carbon electrode was prepared and the electrochemical behavior of glutathione (GSH) at this chemically modified electrode (CME) has been studied by cyclic voltammetry (CV). The results indicated that the modified electrode efficiently exhibited electrocatalytic oxidation for GSH with relatively high sensitivity, stability, and long-life. Coupled with high-performance liquid chromatography (HPLC), the Pd/IrO(2) modified electrode was utilized for the electrochemical detection (ECD) of the thiocompounds, glutathione and cysteine (Cys). The peak currents were linear with the substance concentrations in the range of 1.0 x 10(-5) mol L(-1) to 8.0 x 10(-4) mol L(-1) for GSH and 4.0 x 10(-6) mol L(-1) to 2.0 x 10(-4) mol L(-1) for Cys. The detection limits were 2.0 x 10(-6) mol L(-1) for GSH and 5.0 x 10(-7) mol L(-1) for Cys with S/N of 3. The method has been successfully applied to assess the contents of GSH and Cys in rat brain microdialysates.     

流动注射化学发光抑制法测定抗坏血酸

基于抗坏血酸对Ｌｕｍｉｎｏｌ－ＫＩＯ４－Ｈ２Ｏ２体系化学发光反应的抑制作用,建立了化学发光抑制快速测定抗坏血酸的新方法。该方法线性范围为１．０＊１０＾－７－１．０＊１０＾－５ｍｏｌ／Ｌ,检出限为６．０＊１０＾－８ｍｏｌ／Ｌ,对８．０＊１０＾－７ｍｏｌ／Ｌ抗坏血酸１１次平行测定的相对标准偏差为１．０％。用于维生素Ｃ片剂及注射液中抗坏血酸含量的测定,结果令人满意。     

Tris(2,2'-bipyridyl)ruthenium(II)-zirconia-Nafion composite films applied as solid-state electrochemiluminescence detector for capillary electrophoresis

The major goal of this work was to develop a new solid-state electrochemiluminescence (ECL) detector suitable for capillary electrophoresis (CE). The detector was fabricated by coating a sol-gel derived zirconia (ZrO(2))-Nafion composite film on a graphite electrode, then the zirconia-Nafion modified electrode was immersed in tris(2,2'-bipyridyl)ruthenium(II) (Ru(bpy)(3) (2+)) solution to immobilize this active chemiluminescence reagent. The voltammetric and ECL behaviors of the detector were investigated and optimized in tripropylamine solution. The ratio of 53% for zirconia in the zirconia-Nafion composite provided the highest luminescence intensity of immobilized Ru(bpy)(3) (2+). The ECL can maintain its stability very well in the phosphate solution in the period of 5-90 h when the solid-state ECL detector was immersed in the solution all the time. The optimum distance of capillary outlet to the solid-state ECL detector has been found to be ca. 50-80 microm for a 75 microm capillary. The effects of ionic strength and pH of ECL solution on peak height were investigated. The CE with solid-state ECL detector system was successfully used to detect tripropylamine, lidocaine, and proline. The detection limits (S/N = 3) were 5 x 10(-9) mol.L(-1) for tripropylamine, 1 x 10(-8) mol.L(-1) for lidocaine and 5 x 10(-6) mol.L(-1) for proline, and the linear ranges were from 1.0 x 10(-8) to 1.0 x 10(-5) mol.L(-1) for tripropylamine, 5.0 x 10(-7) mol.L(-1) to 1.0 x 10(-5) mol.L(-1) for lidocaine and 1.0 x 10(-5) to 1.0 x 10(-3) mol.L(-1) for proline, respectively.     

Flow-injection chemiluminometric determination of some thioxanthene derivatives in pharmaceutical formulations and biological fluids using the [Ru(dipy)3(2+)]-Ce(IV) system.

A flow-injection (FI) methodology using tris(2,2'-dipyridyl)ruthenium(II), [Ru(dipy)3(2+)], chemiluminescence (CL) was developed for the rapid and sensitive determination of three thioxanthene derivatives, namely zuclopenthixol hydrochloride, flupentixol hydrochloride and thiothixene. The method is based on the CL reaction of the studied thioxanthenes with [Ru(dipy)3(2+)] and Ce(IV) in a sulfuric acid medium. Under the optimum conditions, calibration graphs were obtained over the concentration ranges 0.002-6 migrograms/ml for zuclopenthixol hydrochloride, 0.5-15 micrograms/ml for flupentixol hydrochloride and 0.05-7.5 micrograms/ml for thiothixene. The limits of detection (s/n = 3) were 4.2 x 10(-9) mol/l zuclopenthixol hydrochloride, 2 x 10(-8) mol/l flupentixol hydrochloride and 4.5 x 10(-8) mol/l thiothixene. The method was successfully applied to the determination of these compounds in dosage forms and biological fluids.     

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

Asensitive 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)₃]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 120 μL 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(R²=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 signi-ficantly 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 Sensor for the Determination of Hydroxylamine by Electrostatically Immobilizing Luminol and Periodate

IntroductionAnalytical methods based on chemilumi-nescence( CL ) reactions have received considerableattention for theirapplication in various fields,ow-ing to their extremely high sensitivity along withother advantages such as wide linear dynamicrange,simple instrumentation,easy miniaturiza-tion and coupling to various separation tech-niques[1— 6] .CL sensors have been developed for be-ing used as the continuous and real- time monitorsof inorganic,organic,biological and pharmaceuti-cal comp…     

流动注射-鲁米诺-高碘酸钾-过氧化氢体系的化学发光行为及其应用

详细研究了流动注射－鲁米诺－高碘酸钾－过氧化氢体系化学发光行为，给出了反应的最佳条件。拟定了一种化学发光测定过氧化氢的新方法。方法的检测限为３．０Ｘ１０－８ｍｏｌ／ＬＨ２Ｏ２；线性范围为２．０×１０－７～６．０×１０－４ｍｏｌ／Ｌ。评价了该体系的应用前景。