Post‐chemiluminescence determination of chloramphenicol based on luminol–potassium periodate system

A post‐chemiluminescence (PCL) phenomenon was observed when chloramphenicol was injected into a mixture of luminol and potassium periodate after the chemiluminescence (CL) reaction of luminol–potassium periodate had finished. The possible reaction mechanism was proposed based on studies of the CL kinetic characteristics, the CL spectra, the fluorescence spectra and the UV‐vis absorption spectra of the related substances. Based on the PCL reaction, a rapid and sensitive method for the determination of chloramphenicol was established. The linear response range was 6.0 × 10^?7–1.0 × 10^?5 mol/L, with a correlation coefficient of 0.9986. The relative standard deviation (RSD) for 5.0 × 10^?6 mol/L chloramphenicol was 2.3% (n = 11). The detection limit was 1.6 × 10^?7 mol/L. The method has been applied to the determination of chloramphenicol in pharmaceutical samples with satisfactory results. Copyright © 2011 John Wiley & Sons, Ltd.     

Flow injection chemiluminescence determination of 2‐methoxyestradiol based on inhibition of luminol‐potassium ferricyanide reaction

A novel flow‐injection chemiluminescence (FI‐CL) method is described for the determination of 2‐methoxyestradiol (2‐ME). The method is based on the inhibitory effect of 2‐ME on the CL reaction of luminol and potassium ferricyanide in alkaline solution. Under optimal conditions, net CL intensity was proportional to 2‐ME concentration in synthetic and mouse plasma samples. Corresponding linear regression equations were 8.0 x 10^‐9‐1.0 x 10^‐7g/mL for synthetic samples and 2.0 x 10^‐9‐1.0 x 10^‐7g/mL for plasma samples. Detection limit for synthetic samples and limits for quantification of plasma samples were 8.4 x 10^‐10g/mL (3σ) for synthetic samples and 4.0 x 10^‐9g/mL for mouse samples. A complete analysis was performed for 60 s, including washing and sampling, resulting in a throughput of ≈ 60/h. The proposed method was applied for the determination of 2‐ME in synthetic and mouse plasma samples. Percentage recoveries were 101.0‐102.8% and 98.0‐105.0%, respectively. A possible mechanism responsible for CL reaction is proposed. Copyright © 2012 John Wiley & Sons, Ltd.     

Flow‐injection chemiluminescence of the luminol–potassium periodate system enhanced by TGA–capped CdTe quantum dots for the determination of theophylline

The chemiluminescence (CL) behaviour of the luminol–potassium periodate system enhanced by CdTe quantum dots capped with thioglycolic acid (TGA–CdTe QDs) was studied using kinetic experiments, CL spectra, UV–vis absorption spectra and fluorescence spectra. The production of oxygen‐containing reactant intermediates (O₂^?? and OH^?) in the present CL system was verified by CL. The possible CL mechanism was discussed in detail. Furthermore, theophylline (THP) was determined based on its enhancement of the CL intensity of the CdTe QDs–luminol–potassium periodate system coupled with a flow‐injection technique. Under these optimized conditions, the linear range was found to be from 1.0 × 10^?8 to 1.0 × 10^?5 g/mL with a detection limit of 2.8 × 10^?9 g/mL (3σ). The recoveries for the determination of THP in tablets were from 98.2 to 99.6%.     

Flow‐injection chemiluminescence method to detect a β2 adrenergic agonist

A new method for the detection of β₂ adrenergic agonists was developed based on the chemiluminescence (CL) reaction of β₂ adrenergic agonist with potassium ferricyanide–luminol CL. The effect of β₂ adrenergic agonists including isoprenaline hydrochloride, salbutamol sulfate, terbutaline sulfate and ractopamine on the CL intensity of potassium ferricyanide–luminol was discovered. Detection of the β₂ adrenergic agonist was carried out in a flow system. Using uniform design experimentation, the influence factors of CL were optimized. The optimal experimental conditions were 1 mmol/L of potassium ferricyanide, 10 µmol/L of luminol, 1.2 mmol/L of sodium hydroxide, a flow speed of 2.6 mL/min and a distance of 1.2 cm from ‘Y₂’ to the flow cell. The linear ranges and limit of detection were 10–100 and 5 ng/mL for isoprenaline hydrochloride, 20–100 and 5 ng/mL for salbutamol sulfate, 8–200 and 1 ng/mL for terbutaline sulfate, 20–100 and 4 ng/mL for ractopamine, respectively. The proposed method allowed 200 injections/h with excellent repeatability and precision. It was successfully applied to the determination of three β₂ adrenergic agonists in commercial pharmaceutical formulations with recoveries in the range of 96.8–98.5%. The possible CL reaction mechanism of potassium ferricyanide–luminol–β₂ adrenergic agonist was discussed from the UV/vis spectra. Copyright © 2014 John Wiley & Sons, Ltd.     

Flow‐injection chemiluminescence method for the determination of chloramphenicol based on luminol–sodium periodate order‐transform second‐chemiluminescence reaction

A new chemiluminescence (CL) reaction was observed when chloramphenicol solution was injected into the mixture after the end of the reaction of alkaline luminol and sodium periodate or sodium periodate was injected into the reaction mixture of chloramphenicol and alkaline luminol. This reaction is described as an order‐transform second‐chemiluminescence (OTSCL) reaction. The OTSCL method combined with a flow‐injection technique was applied to the determination of chloramphenicol. The optimum conditions for the order‐transform second‐chemiluminescence emission were investigated. A mechanism for OTSCL has been proposed on the basis of the chemiluminescence kinetic characteristics, the UV‐visible spectra and the chemiluminescent spectra. Under optimal experimental conditions, the CL response is proportional to the concentration of chloramphenicol over the range 5.0 × 10^?7–5.0 × 10^?5 mol/L with a correlation coefficient of 0.9969 and a detection limit of 6.0 × 10^?8 mol/L (3σ). The relative standard deviation (RSD) for 11 repeated determinations of 5.0 × 10^?6 mol/L chloramphenicol is 1.7%. The method has been applied to the determination of chloramphenicol in pharmaceutical samples with satisfactory results. Copyright © 2011 John Wiley & Sons, Ltd.     

A flow injection chemiluminescence method for the determination of lincomycin in serum using a diperiodato-cuprate (III)-luminol system

In this paper, the novel trivalent copper–periodate complex {K₅[Cu(HIO₆)₂], DPC} has been applied in a luminol‐based chemiluminescence (CL) reaction. Coupled with flow injection (FI) technology, the FI‐CL method was proposed for the determination of lincomycin hydrochloride. The CL reaction between luminol and DPC occurred in an alkaline medium. The CL intensity could be greatly enhanced by lincomycin hydrochloride. The relative CL intensity was proportional to the concentration of lincomycin hydrochloride in the range of 1 × 10^?8 to 5 × 10^?6 g mL^?1 and the detection limit was at the 3.5 × 10^?9 g mL^?1 level. The relative standard deviation at 5 × 10^?8 g mL^?1 was 1.7% (n = 9). The sensitive method was successfully applied to the direct determination of lincomycin hydrochloride (ng mL^?1) in serum. A possible mechanism of the lumonol–DPC CL reaction was discussed by the study of the CL kinetic characteristics and the spectra of CL reaction. The oxidability of DPC was studied by means of its electrochemical response. Copyright © 2010 John Wiley & Sons, Ltd.     

Development of a novel chemiluminescence method for the determination of cefazolin sodium in injectable powder and human urine based on a luminol‐Cu(III) complex reaction in alkaline medium

A novel chemiluminescence (CL) method was developed for the determination of cefazolin sodium based on the CL reaction between the [Cu(HIO₆)₂]^5‐Cu(III) complex and luminol in alkaline solution. Results showed that CL emission of Cu(III) complex–luminol in alkaline medium was significantly different from that in acidic medium. A possible mechanism of the enhanced effect of cefazolin on CL emission of the [Cu(HIO₆)₂]^5‐‐ luminol system was proposed. The effect of the reaction conditions on CL emissions was examined. Under optimized conditions, a good linear relationship was obtained between CL intensity and concentrations of cefazolin sodium in the range of 2.0 x 10^‐8 to 2.0 x 10^‐6 g/mL with a correlation coefficient of R² = 0.9978. The limit of detection was 4.58 x 10^‐9 g/mL. The proposed method was applied for the determination of cefazolin sodium in real samples with recoveries of 82.0‐109% with an RSD of 0.7‐2.1%. The proposed method was successfully used for the determination of cefazolin sodium in injectable powder preparations and human urine with satisfactory results. Copyright © 2012 John Wiley & Sons, Ltd.     

Prospects for using a new sequential chemiluminescence strategy for monitoring the caffeine content in soft and energy drinks via the catalytic activities of different nano‐metal oxides

This article suggests a new sequential injection analysis chemiluminescence (SIA‐CL) strategy for monitoring the caffeine (CAF) content in soft and energy drinks using the catalytic activities of different nano‐metal oxides. The present study describes three different SIA‐CL systems (luminol–ferricyanide (III) coupled with Fe₂O₃ or ZnO nanoparticles (NPs), and luminol–H₂O₂ coupled with CuONPs. All experimental conditions were optimized and the linear concentration ranges of pure CAF were evaluated using the calibration graphs. The selectivity of the developed SIA‐CL systems was studied under the influence of various interfering species that may be present in soft or energy drinks such as sodium ions, sucrose, glucose, sodium benzoate, sodium citrate, riboflavin, niacin, citric, phosphoric and ascorbic acids. International Council for Harmonization (ICH) guidelines were obeyed for the validation of the suggested CL methods. The developed SIA‐CL systems displayed linear relationships over the concentration ranges 1.0–350, 5.0–400 and 10.0–400 μg ml^?1 with Fe₂O₃ NPs, ZnO NPs and CuO NPs, respectively. The recorded lower limits of detection and quantification were 0.7, 2.7 and 7.8 μg ml^?1, and 1.0, 5.0 and 10.0 μg ml^?1 for the previously mentioned SIA‐CL systems. The results revealed high selectivity for CAF determination and were in good agreement with those obtained by other reported methods.     

Determination of ampicillin sodium using the cupric oxide nanoparticles–luminol–H2O2 chemiluminescence reaction

A simple and sensitive chemiluminescence (CL) method has been developed for the determination of ampicillin sodium at submicromolar levels. The method is based on the inhibitory effect of ampicillin sodium on the cupric oxide nanoparticles (CuO NPs)–luminol–H₂O₂ CL reaction. Experimental parameters affecting CL inhibition including concentrations of CuO NPs, luminol, H₂O₂ and NaOH were optimized. Under optimum conditions, the calibration plot was linear in the analyte concentration range 4.0 × 10^‐7–4.0 × 10^‐6 mol/L. The limit of detection was 2.6 × 10^‐7 mol/L and the relative standard deviation (RSD) for six replicate determinations of 1 × 10^‐6 mol/L ampicillin sodium was 4.71%. Also, X–ray diffraction (XRD) and transmission electron microscopy (TEM) analysis were employed to characterize the CuO NPs. The utility of the proposed method was demonstrated by determining ampicillin sodium in pharmaceutical preparation. Copyright © 2013 John Wiley & Sons, Ltd.     

An ultrasensitive chemiluminescent method for the tanshinol borneol ester determination and its pharmacokinetic analysis

Tanshinol borneol ester (DBZ), a chemical combination of danshensu and borneol, is an experimental drug that exhibits efficacious anti‐ischemic activity in animal models. In this work, an ultrasensitive chemiluminescence (CL) method for the determination of DBZ was established based on the inhibitory effect of DBZ on the CL signal produced from the reaction between potassium permanganate and luminol in alkaline solution. The CL intensity responded linearly to the concentration of DBZ in the range 2.0 × 10^‐10 to 4.0 × 10^‐8 g/mL with a detection limit of 7 × 10^?11 g/mL. The relative standard deviation (RSD) was 3.8% for 4.0 × 10^?9 g DBZ (n = 11). The proposed method showed characteristics of high sensitivity, simple device and quick. In addition, this proposed method had been applied satisfactorily to the analysis of DBZ in blood. The pharmacokinetics of DBZ in rat has also been studied using the CL method. Copyright © 2013 John Wiley & Sons, Ltd.     

A novel chemiluminescent flow injection analysis of trace amounts of rutin by its inhibition of the luminol–hydrogen peroxide reaction catalyzed by tetrasulfonated colbalt phthalocyanine

Based on the inhibition effect of rutin on the luminol–hydrogen peroxide chemiluminescence (CL) system catalyzed by tetrasulfonated colbalt phthalocyanine (CoTSPc), a sensitive flow‐injection CL method has been developed for the determination of rutin. The CL reaction mechanism was carefully investigated by examining CL emission spectra, UV–visible spectra and variation of reaction conditions. It was found that there existed a linear relationship between CL intensity and the concentration of rutin in the range of 8.0 × 10^?9 to 1.0 × 10^?6 mol L^?1, and the detection limit is 3.8 × 10^?9 mol L^?1. This proposed method is sensitive, convenient and simple, and has been applied to the determination of rutin in commercial rutin tablets with satisfactory results. Copyright © 2009 John Wiley & Sons, Ltd.     

Post-chemiluminescence behaviour of Ni2+, Mg2+, Cd2+ and Zn2+ in the potassium ferricyanide-luminol reaction.

A new chemiluminescence (CL) reaction was observed when Ni2+, Mg2+, Cd2+ or Zn2+ was injected into the reaction mixture after the finish of the CL reaction of alkaline luminol and potassium ferricyanide. This reaction is described as a post-chemiluminescence (PCL) reaction. The possible mechanism for the PCL was proposed based on studies of the CL kinetic characteristic and the CL spectra. The experimental conditions of the CL reactions were optimized and the feasibility of using the reaction to analyse these metal ions was evaluated. The PCL reaction method operates in the ranges: 1 x 10(-7)-8 x 10(-6) g/L Ni2+; 3 x 10(-6)-2 x 10(-4) g/L Mg2+; 8 x 10(-7)-1 x 10(-4) g/L Cd2+; and 2 x 10(-4)-2 x 10(-3) g/L Zn2+, with detection limits of 4 x 10(-8) g/mL, 1 x 10(-6) g/mL, 3 x 10(-7) g/mL, 8 x 10(-5) g/mL, respectively.     

Enhanced chemiluminescence of the luminol–AgNO3 system by Ag nanoparticles

The oxidation reaction of luminol with AgNO₃ can produce chemiluminescence (CL) in the presence of silver nanoparticles (NPs) in alkaline solution. Based on the studies of UV‐vis absorption spectra, photoluminescence (PL) spectra and CL spectra, a CL enhancement mechanism is proposed. The CL emission spectrum of the luminol–AgNO₃–Ag NPs system indicated that the luminophore was still 3‐aminophthalate. On injection of silver nanoparticles into the mixture of luminol and AgNO₃, they catalysed the reduction of AgNO₃ by luminol. The product luminol radicals reacted with the dissolved oxygen, to produce a strong CL emission. As a result, the CL intensity was substantially increased. Moreover, the influences of 18 amino acids, e.g. cystine, tyrosine and asparagine, and 25 organic compounds, including gallic acid, tannic acid and hydroquinone, on the luminol–AgNO₃–Ag NPs CL system were studied by a flow‐injection procedure, which led to an effective method for detecting these compounds. Copyright © 2011 John Wiley & Sons, Ltd.     

Development of chemiluminescence method for determination of 10‐hydroxycamptothecin based on luminol–[Ag(HIO6)2]5− reaction in alkaline solution

A novel chemiluminescence (CL) method was developed for the determination of 10‐hydroxycamptothecin(HCPT) based on the CL reaction between [Ag(HIO₆)₂]^5? and luminol in alkaline solution. CL emission of Ag(III) complex–luminol in alkaline medium was very different from that in acidic medium. A possible mechanism of enhanced CL emission was suggested. The enhanced effect of HCPT on CL emission of the [Ag(HIO₆)₂]^5?–luminol system was found. The enhanced degree of CL emission was proportional to HCPT concentration. The effect of the reaction conditions on CL emission was examined. Under optimal conditions, the limit of detection was 6.5 × 10^?9 g mL^?1. The proposed method was applied for the determination of HCPT in real samples with the recoveries of 93.2–109% with the RSD of 1.7–3.3%. Copyright © 2010 John Wiley & Sons, Ltd.     

Sensitive determination of epinephrine in pharmaceutical preparation by flow injection coupled with chemiluminescence detection and mechanism study

A novel, rapid and sensitive method was described for the determination of epinephrine (EP) using flow injection analysis coupled with chemiluminescence (CL) detection, which based on EP enhanced the weak CL emission of luminol–KIO₄ system in NaOH solution. Parameters affecting the CL intensity and reproducibility were optimized systematically. Under the optimized experiment conditions, the net CL intensity was proportional to the concentration of EP in the range of 5.0 × 10^?8 to 1.5 × 10^?6 mol/L with a detection limit of 1.9 × 10^?9 mol/L. The relative standard deviation (RSD) was found to be 0.7% for 13 replicate determinations of 3.0 × 10^?7 mol/L EP. The applicability of the proposed method was illustrated in the determination of EP in pharmaceutical preparation. The recoveries of EP at different levels in EP hydrochloride injection were between 95.4 and 104.7%. One assay procedure takes only 27 s, and the sampling rate was calculated about to be 130 samples/h. The possible mechanism of the enhanced CL intensity was studied by examining CL spectra and UV–vis spectra. Copyright © 2009 John Wiley & Sons, Ltd.     

Eco‐friendly synthesis of gelatin‐capped bimetallic Au–Ag nanoparticles for chemiluminescence detection of anticancer raloxifene hydrochloride

This study described the utility of green analytical chemistry in the synthesis of gelatin‐capped silver, gold and bimetallic gold–silver nanoparticles (NPs). The preparation of nanoparticles was based on the reaction of silver nitrate or chlorauric acid with a 1.0 wt% aqueous gelatin solution at 50°C. The gelatin‐capped silver, gold and bimetallic NPs were characterized using transmission electron microscopy, UV–vis, X‐ray diffraction and Fourier transform infrared spectroscopy, and were used to enhance a sensitive sequential injection chemiluminescence luminol–potassium ferricyanide system for determination of the anticancer drug raloxifene hydrochloride. The developed method is eco‐friendly and sensitive for chemiluminescence detection of the selected drug in its bulk powder, pharmaceutical injections and biosamples. After optimizing the conditions, a linear relationship in the range of 1.0 × 10^–9 to 1.0 × 10^–1 mol/L was obtained with a limit of detection of 5.0 × 10^–10 mol/L and a limit of quantification of 1.0 × 10^‐9 mol/L. Statistical treatment and method validation were performed based on ICH guidelines. Copyright © 2016 John Wiley & Sons, Ltd.     

Capillary electrophoresis analysis of isoniazid using luminol-periodate potassium chemiluminescence system

A rapid and simple capillary electrophoresis method coupled with chemiluminescent (CL) detection was proposed for analysis of isoniazid (ISO) based on the enhancement effect of ISO to CL emission of luminol‐periodate potassium reaction. Under the optimal conditions, ISO can be assayed in the range of 7.0 × 10^?7 to 3.0 × 10^?5 g mL^?1 (R² = 0.9990) with a limit of detection of 3.0 × 10^?7 g mL^?1 (signal‐to‐noise ratio of 3). The whole analysis process can be completed within 2.5 min with a theoretical plate number of 6258. The relative standard deviations of the signal intensity and the migration time were 3.1 and 1.4% for a standard sample at 1.0 × 10^?5 g mL^?1 (n = 5), respectively. The presented novel strategy was successfully applied to the determination of ISO in commercial pharmaceutical preparations and spiked human serum samples. Copyright © 2010 John Wiley & Sons, Ltd.     

Determination of trace amounts of dopamine by flow‐injection analysis coupled with luminol–Ag(III) complex chemiluminescence detection

A novel flow injection analysis‐direct chemiluminescence (FI‐CL) method has been developed for determination of trace amounts of dopamine (DA) based on the enhancing effect of DA on the CL reaction of luminol with an Ag(III) complex in alkaline solution. Under optimum conditions, CL intensities are proportional to the concentration of DA in the range of 1.0 × 10^?10 to 4.0 × 10^?8 mol L^?1. The detection limit is 3.0 × 10^?11 mol L^?1 for DA (3s), with a relative standard deviation (n = 13) of 2.3% for 1.0 × 10^?8 mol L^?1 DA. This method has also been applied for the determination of DA in commercial pharmaceutical injection samples. On the basis of the CL spectra and the results of the free‐radical trapping experiment of this work, a reaction mechanism for this CL reaction is proposed and discussed. Copyright © 2010 John Wiley & Sons, Ltd.     

Sensitive determination of 2‐methoxyestradiol in pharmaceutical preparations and serum samples using flow injection chemiluminescence

A rapid and sensitive flow injection chemiluminescence (FI–CL) method is described for the determination of 2‐methoxyestradiol (2ME) based on enhancement of the CL intensity from a potassium ferricyanide–calcein system in sodium hydroxide medium. The optimum conditions for the CL emission were investigated. Under optimized conditions, a linear calibration graph was obtained over the range 1.0 × 10^‐8 to 1.0 × 10^‐6 mol/L (r = 0.998) 2ME with a detection limit (3σ) of 5.4 × 10^‐9 mol/L. The relative standard deviation (RSD) for 5.0 × 10^‐7 mol/L 2ME was 1.7%. As a preliminary application, the proposed method was successfully applied to the determination of 2ME in injection solutions and serum samples. The possible CL mechanism was also proposed. Copyright © 2013 John Wiley & Sons, Ltd.     

Electrophoresis–chemiluminescence detection of phenols catalyzed by hemin

Based on the catalytic activity of hemin, an efficient biocatalyst, an indirect capillary electrophoresis–chemiluminescence (CE‐CL) detection method for phenols using a hemin–luminol–hydrogen peroxide system was developed. Through a series of static injection experiments, hemin was found to perform best in a neutral solution rather than an acidic or alkaline medium. Although halide ions such as Br^? and F^? could further enhance the CL signal catalyzed by hemin, it is difficult to apply these conditions to this CE‐CL detection system because of the self‐polymerization of hemin, as it hinders the CE process. The addition of concentrated ammonium hydroxide to an aqueous/dimethyl sulfoxide solution of hemin–luminol afforded a stable CE‐CL baseline. The indirect CE‐CL detection of five phenols using this method gave the following limits of detections: 4.8 × 10^?8 mol/L (o‐sec‐butylphenol), 4.9 × 10^?8 mol/L (o‐cresol), 5.4 × 10^?8 mol/L (m‐cresol), 5.3 × 10^?8 mol/L (2,4‐dichlorophenol) and 7.1 × 10^?8 mol/L (phenol). Copyright © 2013 John Wiley & Sons, Ltd.