Applications of capillary electrophoresis with chemiluminescence detection in clinical,environmental and food analysis. A review

This paper reviews the latest developments and analytical applications of chemiluminescence detection coupled to capillary electrophoresis (CE-CL). Different sections considering the most common CL systems have been included, such as the tris(2,2?-bipyridine)ruthenium(II) system, the luminol and acridinium derivative reactions, the peroxyoxalate CL or direct oxidations. Improvements in instrumental designs, new strategies for improving both resolution and sensitivity, and applications in different fields such as clinical, pharmaceutical, environmental and food analysis have been included. This review covers the literature from 2010 to 2015.     

Advances and analytical applications in chemiluminescence coupled to capillary electrophoresis

The present review presents the state of the art of the developments, key strategies and analytical applications of chemiluminescence detection coupled to CE (CE‐CL). Different parts considering the most common CL systems have been included, such as the tris(2,2′‐bipyridine)ruthenium(II) system, the luminol and derivatives reaction, the peroxyoxalate CL or direct oxidations. New advances in homemade configurations and applications in different fields such as clinical, pharmaceutical, environmental and food analysis have been included. The focus is on studies which appeared from 2000 to the end of 2009.     

Flow injection chemiluminescence detection and solvent extraction for human skin ointment dexamethasone acetate absorption analysis and the reaction mechanism study

A flow-injection chemiluminescence (CL) method coupled with solvent extraction for the determination of dexamethasone acetate (DA) in ointment was presented in this paper. It was based on the enhancing effect of the studied drug on CL emission of luminol–K₃Fe(CN)₆ system. This method has the advantages of simple sample treatment, cheap instrumentation and rapid detection. Under the optimum conditions, relative CL intensities were proportional to DA concentrations in the 0.044–4.4 μg ml⁻¹ range. The limit of detection was 0.01 μg ml⁻¹ (3σ) for DA. The method was applied to DA quantification in commercial DA ointment pharmaceutical and to human skin DA absorption analysis. Experiments were performed to evaluate the nature of DA enhanced luminol–K₃Fe(CN)₆ CL reaction. Based on the experimental results, it was suggested that in this CL system, DA was oxidized by K₃Fe(CN)₆ to form a medium product (DAox), DAox oxidized luminol with a faster kinetic step comparing with K₃Fe(CN)₆ oxidized luminol to an active form. As a result, DA speed the luminol CL reaction, and finally intensified the CL signal.     

鲁米诺化学发光分析法研究进展

从化学发光反应机理和应用进展两个方面对鲁米诺-过氧化氢、鲁米诺-铁氰化钾、鲁米诺-碘化物、鲁米诺-高锰酸钾和鲁米诺-溶解氧等化学发光体系进行了综述;指出鲁米诺化学发光体系是应用最为广泛的一类化学发光体系,同时对鲁米诺化学发光分析法的发展方向进行了展望.     

Determination of peroxidase encapsulated in liposomes using homogentisic acid y-lactone chemiluminescence.

Homogentisic acid gamma-lactone (HAL) chemiluminescence (CL) was applied to the determination of horseradish peroxidase (HRP) encapsulated in liposomes. HRP was detected after the lysis of HRP-trapped liposomes with Triton X-100. CL response rate, detection limit and linear range of calibration curve for HRP in HAL CL were compared with those in piodophenol (p-IP)-enhanced luminol CL. Maximal light emission in HAL CL appeared more rapidly compared to that in p-IP enhanced luminol CL, thus resulting in remarkable reduction of CL measurement time. The detection limit for HRP in HAL CL was the same as that in p-IP-enhanced luminol CL. The linear range of calibration curve for HRP in HAL CL was improved by a factor of 50 compared with that in p-IP-enhanced luminol CL. From these results, it was found that HAL CL were superior to p-IP-enhanced luminol CL for the determination of HRP encapsulated in liposomes.     

An ultrasensitive and highly selective determination method for quinones by high-performance liquid chromatography with photochemically initiated luminol chemiluminescence

Quinones are a class of compounds of substantial toxicological and pharmacological interest. An ultrasensitive and highly selective chemiluminescence (CL) method was newly developed for the determination of quinones based on the utility of photochemically initiated luminol CL. The method involved ultraviolet (UV) irradiation of quinones to generate reactive oxygen species (ROS) through the unique photosensitization reaction accompanied with the photolytical generation of 3,6-dihydroxyphthalic acid (DHPA) from quinones. The photoproducts were detected by luminol CL reaction. Interestingly, it was noticed that DHPA had enhancement effect for the luminol CL. The generation of the enhancer (DHPA) in association with the oxidant (ROS) in the photochemical reaction greatly increases the sensitivity and selectivity of the proposed luminol CL method. In order to elucidate the type of ROS produced by the photosensitizaion reaction in relation to the proposed CL reaction, we investigated the quenching effect of selective ROS scavengers in the luminol CL. Although several ROS were generated, superoxide anion was the most effective ROS for the generated CL. Moreover, the enhancement mechanism of DHPA for luminol CL was confirmed. The enhancement was found to be through the formation of stabilized semiquinone anion radical that provided long-lived CL. The generation of the semiquinone radical was confirmed by electron spin resonance technique. Furthermore, we developed an HPLC method with on-line photochemical reaction followed by the proposed CL detection for the determination of four quinones. A luminol analogue, L-012, was used for its high sensitivity. The detection limits for quinones obtained with the proposed method (S/N = 3) were in the range 1.5–24 fmol that were 10–1000 times more sensitive compared with the previous methods. Finally, the developed HPLC-CL system was successfully applied for the determination of quinones in airborne particulate samples collected at Nagasaki city.     

Highly sensitive trivalent copper chelate-H2O2 system for CE-chemiluminescent detection of luminol-type compounds

Luminol-type compounds can be used as chemiluminescent (CL) derivatization reagents for amines, carboxylic acids and protein. Copper chelate diperiodatocuprate(III) (K5[Cu(HIO6)2], DPC) was synthesized by complexation of copper at trivalent oxidation state and periodate in a strong basic medium. It was found that DPC can greatly enhance the reaction between luminol-type compounds and H2O2 to produce very strong CL emission. Based on this fact, a rapid CE method combined with high-sensitive end-column CL detection was established to simultaneously analyze luminol and N-(4-aminobutyl)-N-ethylisoluminol (ABEI) with wide concentration range of 3.0-300 nmol/L in 5 min. The RSDs of the signal intensity and the migration time were less than 3.9 and 7.0% for a standard sample containing 100 nmol/L luminol and ABEI (n=5), respectively. The investigation implies that DPC is a promising sensitizer for CE-CL detection of a great variety of biomolecules and drugs in biological samples after derivatization using luminol derivatives.     

液相色谱-化学发光检测法的最新进展

评述了近年来液相色谱－化学发光检测法的最新进展,参考文献从１９９２年到１９９５年。内容涉及各类化学发光反应同液相色谱体系的耦合方式,仪器设计,多种无机、有机、生物大分子、生物活性物质及药物的分析方法及其在环境、生物医学科学和生命科学、临床化学及药物化学中的应用和发展方向。     

Procedures for the enhancement of selectivity in liquid phase chemiluminescence detection

An overview of liquid phase chemiluminescence (CL) processes is presented and the potential for CL detection in liquid chromatography (LC) is discussed, with particular reference to the luminol and peroxyoxalate reactions. Post column ion displacement from a solid phase reagent [a cation exchange resin in the copper(II) form] followed by catalysis of the luminol reaction is used for the quantification of mixtures of weak acids after separation by ion-exclusion chromatography. Polyaromatic hydrocarbons (PAHs) released during the combustion of biomass fuels are separated by reversed-phase chromatography and quantified by their sensitizing effect on the peroxyoxalate reaction. This procedure is also used for the determination of carboxylic acids in non-aqueous media after selective pre-column derivatization with a fluorescent label (9-anthracenemethanol).     

Analytical assessment of the oscillating chemical reactions by use chemiluminescence detection

This paper introduces the chemiluminescence (CL) detection in oscillating reaction-based determinations using the analyte pulse perturbation technique, a straightforward and expeditious approach to deriving quantitative analytical information from oscillating chemical reactions. The behavior of the H(2)O(2)-KSCN-CuSO(4)-NaOH oscillating system in the presence of luminol was examined by using the proposed detection method and the classical potentiometric technique. Some analytical and practical aspects of both detection systems are discussed. A new analytical method for the determination of vitamin B(6) based on the sequential perturbation produced by different amounts of this substance on the oscillating chemical system was also developed in order to assess the potential of CL detection for routine analyses. The calibration curve thus obtained was linear over the range 0.5-2.0 mumol of vitamin B(6), and the precision and throughput were also quite good (3.04% as RSD and nine samples h(-1), respectively). The proposed method was validated by determining the vitamin in pharmaceutical preparations.     

A capillary electrophoresis detection scheme for underivatized amino acids based on luminol-BrO- chemiluminescence system

A novel chemiluminescence (CL) detection scheme has been developed for detecting underivatized amino acids following capillary electrophoresis (CE) separation. This detection was based on the inhibitory effect of amino acids on the CL reaction between luminol and BrO⁻ in alkaline aqueous solution. Detection of amino acids was accomplished with a borate-based background electrolyte at pH 9.2. The luminol was used as a component of the separation carrier electrolyte. Parameters affecting CE-CL separation and detection, such as the pH value, the concentration of electrolyte and CL reagent on the resolution were optimized. The relative standard deviation for the analysis of amino acids was less than 1.5% for the migration time and 4% for the peak height. The mass limits of detection were from 7 to 144 fmol for the 7 amino acids. This method has been applied of 7 amino acids in amino acid injection.     

Pt NPs catalyzed chemiluminescence method for Hg2+ detection based on a flow injection system

Establishing a simple and accurate method for Hg²⁺ detection is of great importance for the environment and human health. In this work, platinum nanoparticles (Pt NPs) with different capped agents and morphologies were synthesized. It was found that Pt NPs exhibited peroxidase‐like activity that can catalyze the chemiluminescence (CL) of the luminol system without H₂O₂. The most intensive CL signals were obtained by using PVP‐capped Pt NPs as catalysis. Based on the fact that Hg²⁺ could further enhance the CL intensity in the Pt NPs‐luminol CL system, a Pt NPs‐catalyzed CL method based on a flow injection system is developed for the sensitive analysis of Hg²⁺. When the concentration of Hg²⁺ in the system increases, the CL intensity would together increase, thereby achieving sensitive Hg²⁺ detection. The limit of detection (LOD) was calculated to be 8.6 nM. This developed method provides a simple and rapid approach for the sensitive detection of Hg²⁺ and shows great promise for applications in other complex systems.     

流动注射化学发光检测法的进展

评述近年来流动注射化学发光检测法及生物发光检测法的最新进展。内容涉及各类化学发光反应、生物发光和电致化学发光反应同流主射体系的耦合方式，仪器设计，多种无机、有机、生物大分子、生物活性的药物的分析方法及其在环境、生物医学客生命科学、化学及药物化学中的应用和发展方向。     

液相色谱化学发光检测法的新进展

本文评述了近年来液相色谱化学发光检测法的新进展，内容涉及各类化学发光发反应，生物发光反应和电致化学发光反应同色谱体系的偶合方式，仪器设计，多种无机，有机，生物大分子和生物活性物质的分析方法及其在环境，生物医学科学和生命科学中的应用和发展方向。引用文献１６８篇。     

Chemiluminescence of Luminol–Graphene Oxide for the Sensitive Detection of Puerarin in Biological Fluid and Chinese Gegen

Graphene oxide (GO ), one of the water‐soluble derivatives of graphene, could initiate strong chemiluminescence (CL ) emission of luminol in the absence of any oxidant, and then the CL intensity was inhibited by puerarin (PUE ), a main component in the traditional Chinese medicine Gegen. Based on this, a novel CL method was established for the determination of PUE . This method showed a linear relationship between the CL signal and the logarithm of PUE concentration in the range 0.01–6.00 μM . The limit of detection was 2.83 nM and the relative standard deviation (RSD ) was 1.94% for 11 determinations of 0.4 μM PUE . This method was successfully used for the determination of PUE in Gegen and human urine samples. The possible CL reaction mechanism was investigated by UV –vis, fluorescence, and CL spectra, as well as by some chemical experiments.     

Efficient chemiluminescence by aptamer – reactant platform combination with activated Ag–Au alloy nanoparticles for cobalt detection

This article deals with the detection of Co(II) in real water sample using aptamer – reactant platform combination with activated Ag–Au alloy nanoparticles (NPs) by chemiluminescence (CL) method. CL is attributed to a catalytically enhanced decomposition of H₂O₂ by aptamer conjugated Ag–Au alloy NPs to produce reactive oxygen species. The Ag–Au alloy NPs were prepared by chemical method using double reducing agent (i.e. trisodium citrate and polyethylenimine) and used for detection of Co(II) from water by CL method. CL experiments were carried out with the variation of different parameters such as pH, concentration of luminol, concentration of H₂O₂ and Ag–Au alloy NPs. We found that Ag–Au alloy NPs have very good efficiency towards Co(II) detection. Analytical parameters and kinetics were studied in detail to know the nature and mechanism of CL in presence of aptamer conjugated Ag–Au alloy NPs. The linear range of the CL sensor of Co(II) is covered concentration from 0.01 to 10 µg/L with detection limit of 0.001 µg/L. The relative standard deviation for determination of Co(II) was 6.65 in 10 replicated measurements. CL method is first time applied to detect the Co(II) in real water samples at very low level using aptamer conjugated Ag–Au NPs as a catalyst.     

A G‐quadruplex/hemin DNAzyme‐based microchip electrophoresis chemiluminescence assay for highly sensitive detection of biotin in flour

Quantitative analysis of biotin in biological fluids, foods, and pharmaceutical is important for diagnosis and treatment of biotin‐related diseases and health maintenance. In this work, a novel G‐quadruplex/hemin DNAzyme‐based microchip electrophoresis chemiluminescence (CL) assay method was established for rapid and highly sensitive detection of biotin. This method is based on the specific binding between biotin and streptavidin, the catalytic CL characteristics of G‐quadruplex/hemin DNAzyme to the oxidation–reduction reaction of hydrogen peroxide with luminol, and the on‐line separation function of microchip electrophoresis. Under the optimal experimental conditions, on‐chip biotin analysis was achieved within 1 min. The CL intensity is linearly proportional to the concentration of biotin in the range of 13–630 nM with a detection limit of 6.4 nM. The proposed method has been applied for the detection of biotin in flour, biotin contents in three flour samples are found in the range of 199–223 ng/g with a mean value of 214 ng/g. The recoveries were in the range of 94–103%. With excellent sensitivity and good selectivity, the proposed method could be applied in a wide range of biological fluids, foods, and pharmaceutical analysis.     

Sensitive determination of norepinephrine,epinephrine, dopamine and 5‐hydroxytryptamine by coupling HPLC with [Ag(HIO6)2]5−–luminol chemiluminescence detection

Based on the enhancing effects of norepinephrine (NE), epinephrine (EP), dopamine (DA) and 5‐hydroxytryptamine (5‐HT) on the chemiluminescence (CL) reaction between [Ag(HIO₆)₂]^5? and luminol in alkaline solution, a high‐performance liquid chromatography (HPLC) method with CL detection was explored for the sensitive determination of monoamine neurotransmitters for the first time. The UV–visible absorption spectra were recorded to study the enhancement mechanism of monoamine neurotransmitters on the CL of [Ag(HIO₆)₂]^5? and luminol reaction. The HPLC separation of NE, EP, DA and 5‐HT was achieved with isocratic elution using a mixture of aqueous 0.2% phosphoric acid and methanol (5:95, v/v) within 11.0 min. Under the optimized conditions, the detection limits of NE, EP, DA, and 5‐HT were 4.8, 0.9, 1.9 and 2.3 ng/mL, respectively, corresponding to 17.6–96.0 pg for 20 μL sample injection. The recoveries of monoamine neurotransmitters in rat brain were >95.6% with the precisions expressed by RSD <5.0%. The validated HPLC‐CL method was successfully applied for the quantification of NE, EP, DA and 5‐HT in rat brain. This method has promising potential for some biological and clinical investigations focusing on the levels of monoamine neurotransmitters. Copyright © 2016 John Wiley & Sons, Ltd.     

Simultaneous chemiluminescent determination of carbaryl and 1-naphthol in soils using a flow-injection system

A flow-injection method coupled with the luminol chemiluminescence (CL) detection was developed for the simultaneous determination of carbaryl and 1-naphthol in soils. The method is based on the inhibition of luminol oxidation by the presence of 1-naphthol with the consequent reduction in the CL intensity. The conversion of carbaryl into 1-naphthol was made by the alkaline hydrolysis with NaOH. Under the optimised conditions, the method permits the determination of carbaryl and 1-naphthol over the range 25–400 ng mL^?1 with high determination coefficient using both peak area and height, and high sample throughput (40 h^?1). The detection limits applying the International Unión of Pure and Applied Chemistry (IUPAC) criteria were 65 ng g^?1 and 123.5 ng g^?1 for peak height and area, respectively. A simple extraction procedure employing chloroform as the solvent and sonication was effective for the complete extraction of the analytes present in soils. The method was validated by the analysis of spiked samples, with recoveries between 88.7 and 103.1%. The Flow Injection-Chemiluminescence (FI-CL) method has proven to be simple, fast and accurate for the quantification of carbaryl and its main degradation product in soils.