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 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.     

The determination of glutamine with flow‐injection chemiluminescence detection and mechanism study

The main purpose of this study was to develop an inexpensive, simple, rapid and sensitive chemiluminescence (CL) method for the determination of glutamine (Gln) using a flow‐injection (FI) system. Gln was found to strongly inhibit the CL signal of the luminol–H₂O₂–CuSO₄ system in Na₂B₄O₇ solution. A new FI‐CL method was developed for the determination of Gln. Parameters affecting the reproducibility and CL detection were optimized systematically. Under the optimized conditions, the corresponding linear regression equation was established over the range of 5.0 × 10^?7 to 2.5 × 10^?6 mol/L with the detection limit of 1.8 × 10^?8 mol/L. The relative standard deviation was found to be 1.8% for 11 replicate determinations of 1.5 × 10^?6 mol/L Gln. The proposed method has been satisfactorily applied for the determination of Gln in real samples (Marzulene‐s granules) with recoveries in the range of 98.7–108.6%. The minimum sampling rate was about 100 samples/h. The possible mechanism of this inhibitory CL was studied by fluorescence spectrophotometer and UV–vis spectrophotometer. Copyright © 2009 John Wiley & Sons, Ltd.     

DPPH·–luminol chemiluminescence system and its application in the determination of scutellarin in pharmaceutical injections and rat plasma with flow injection analysis

In this article, a DPPH·–luminol chemiluminescence (CL) system was reported and the CL mechanism was discussed according to the CL kinetic properties after sequence injecting DPPH· into the DPPH·–luminol reaction mixture. It was observed that scutellarin could inhibit the CL response of the DPPH·–luminol system. Based on this observation, a simple and rapid flow injection CL method was developed for the determination of scutellarin using the inhibition effect in alkaline medium. The optimized chemical conditions for the CL reaction were 5 × 10^?6 mol/L DPPH · and 1.0 × 10^?4 mol/L luminol in 0.01 mol/L NaOH. Under optimized conditions, the CL intensity was inversely proportional to the concentration of scutellarin over the ranges 5–2000 and 40–3200 ng/ml in pharmaceutical injection and rat plasma, respectively. The limits of detection (S/N  = 3) were 5 and 40 ng/ml in preparations and rat plasma, respectively. Furthermore, the precision, recovery and stability of the validated method were acceptable for the determination of scutellarin in both pharmaceutical injections and rat plasma. The presented method was successfully applied in the determination of scutellarin in pharmaceutical injections and real rat plasma samples.     

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.     

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.     

Effect of colloidal β-cyclodextrins-Fe(3) O(4) magnetic nanoparticles on the chemiluminescence enhancement of luminol-Ag(III) complex for rapid and sensitive determination of cysteine in human serum

Colloidals solution of Fe₃O₄ magnetic nanoparticles (MNPs), capped with β‐cyclodextrins (β‐CD) as inclusion complexes, were found to enhance the chemiluminescence (CL) intensity of the luminol–diperiodatoargentate(III) (DPA) system. On injection of cysteine into the luminol–DPA–β‐CD–Fe₃O₄ MNPs inclusion complexes system, the CL intensity is strongly enhanced. The enhanced CL signal is ascribed to the catalytic effect of Fe₃O₄ MNPs capped with β‐CD, which is assumed to stabilize the CL intermediate. Based on these findings, a rapid and sensitive assay was developed for the determination of cysteine in human serum. The effects of analytical variables on the CL signal were studied and optimized. Under the optimum conditions, the CL intensity was directly proportional to the concentration of cysteine in the range 8.0 × 10^–9–1.0 × 10^–6 mol/L. The detection limit was 2.8 × 10^–9 mol/L (3 S_b/m) and the relative standard deviation (RSD) for 10 replicate determinations of 1.0 × 10^–7 mol/L cysteine was 3.5%. The proposed method was applied to the sensitive determination of cysteine in human serum samples, and compared with the Ellman method with satisfactory results. Copyright © 2011 John Wiley & Sons, Ltd.     

Cupric oxide nanoparticles‐enhanced chemiluminescence method for measurement of β‐lactam antibiotics

A simple, sensitive cupric oxide nanoparticles (CuO NPs) enhanced chemiluminescence (CL) method was developed for the measurement of β‐lactam antibiotics, including amoxicillin and cefazolin sodium. The method was based on suppression of the CuO NPs–luminol–H₂O₂ CL reaction by β‐lactam antibiotics. Experimental parameters that influenced the inhibitory effect of the antibiotic drugs on the CL system, such as NaOH (mol/L), luminol (µmol/L), H₂O₂ (mol/L) and CuO NPs (mg/L) concentrations, were optimized. Calibration graphs were linear and had dynamic ranges of 1.0 × 10^–6 to 8.0 × 10^–6 mol/L and 3.0 × 10^–5 to 5.0 × 10^–3 mol/L for amoxicillin and cefazolin sodium, respectively, with corresponding detection limits of 7.9 × 10^–7 mol/L and 1.8 × 10^–5 mol/L. The relative standard deviations of five replicate measurements of 5.0 × 10^–6 amoxicillin and 5 × 10^–4 cefazolin sodium were 5.43 and 5.01%, respectively. The synthesized CuO NPs were characterized by X‐ray diffraction (XRD) and transmission electronmicroscopy (TEM). The developed approach was exploited successfully to measure antibiotics in pharmaceutical preparations. Copyright © 2014 John Wiley & Sons, Ltd.     

Chemiluminescence sensor for sulfonylurea herbicide using molecular imprinted microspheres as recognition element

Uniform molecular imprinting microspheres were prepared using precipitation polymerization with thifensulfuron‐methyl (TFM) as template, acrylamide as functional monomer and ethylene glycol dimethacrylate as cross‐linker. TFM could be selectively adsorbed on the molecularly imprinted polymers (MIPs) matrix through the hydrogen bonding interaction and the adsorbed TFM could be sensed by its strikingly enhancing effect on the weak chemiluminescence (CL) reaction between luminol and hydrogen peroxide. On this basis, a novel CL sensor for the determination of TFM using MIPs as recognition elements was established. The logarithm of net CL intensity (ΔI) is linearly proportional to the logarithm of TFM concentration (C) in the range from 1.0 × 10^?9 to 5.0 × 10^?5 mol L^?1 with a detection limit of 8.3 × 10^?10 mol L^?1 (3σ). The results demonstrated that the MIP–CL sensor was reversible and reusable and that it could strikingly improve the selectivity and sensitivity of CL analysis. Furthermore, it is suggested that the CL enhancement of luminol–H₂O₂ by TFM might be ascribed to the enhancement effect of CO₂, which came from TFM hydrolysis in basic medium. Copyright © 2010 John Wiley & Sons, Ltd.     

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.     

A novel method for sensing of methimazole using gold nanoparticle‐catalyzed chemiluminescent reaction

Based on the inhibition effect of methimazole (MMI) on the reaction of luminol–H₂O₂ catalyzed by gold nanoparticles, a novel chemiluminescence (CL) method was developed for the determination of MMI. Under the optimum conditions, the relative CL intensity was linearly related to MMI concentration in the range from 5.0 × 10^?8 to 5.0 × 10^?5 mol L^?1. The detection limit was 1.6 × 10^?8 mol L^?1 (S/N = 3), and the RSD for 6.0 × 10^?6 mol L^?1 MMI was 4.83 (n = 11). This method has high sensitivity, wide linear range, inexpensive instrumentation and has been applied to detect MMI in pharmaceutical tablets and pig serum samples. Furthermore, a possible reaction mechanism is discussed. Copyright © 2010 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.     

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%.     

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.     

DNA‐based chemiluminescent nanoprobes for highly sensitive and selective detection of mercury(II) ion

A simple and sensitive DNA‐stablized gold nanoparticle (AuNP)‐based chemiluminescent (CL) probe for detecting mercury ion (Hg²⁺) in aqueous solution has been developed. The CL strategy relies upon the catalytic activity of unmodified AuNPs on the luminol–H₂O₂ CL reaction, and the interaction of unmodified AuNPs with DNA. The unmodified AuNPs can effectively differentiate unstructured and folded DNA. The DNA desorbs from AuNPs in the presence of Hg²⁺, leading to the increase in CL signal. By rationally varying the number of thymine in single‐strand oligonucleotides, the detection range could be tuned. Employing single‐strand oligonucleotides with 14 thymine in the detecting system, a sensitive linear range for Hg²⁺ ions from 5.0 × 10^–10 to 1.0 × 10^–7 mol/L and a detection limit of 2.1 × 10^–10 mol/L are obtained. Changing the number of thymine to 10 and 6, it leads to a narrow detection range but a high sensitivity. Besides, DNA‐based CL nanoprobes exhibit a remarkable selectivity for Hg²⁺ ions over a variety of competing metal ions. Copyright © 2012 John Wiley & Sons, Ltd.     

Determination of rutin by flow injection chemiluminescence method using the reaction of luminol and potassium hexacyanoferrate(III) with the aid of response surface methodology

A novel flow injection chemiluminescence (CL) method for the determination of rutin was reported. The proposed method was based on the enhanced effect of rutin on the chemiluminescence intensity of luminol and potassium hexacyanoferrate(III) reaction in NaOH medium. The variables of reaction system, such as luminol concentration, potassium hexacyanoferrate(III) concentration and NaOH concentration, were optimized with the aid of response surface methodology. For the responses prediction, a second‐order polynomial model (SOPM) was applied. The optimal conditions for determination of rutin estimated by the model equation were as follows: NaOH concentration of 0.13 mol/L luminol concentration of 0.94 × 10^?6 mol/L, and K₃Fe(CN)₆ concentration of 1.09 × 10^?4 mol/L. The theoretical increased ratio of CL intensity (IRI) predicted and actual IRI for 0.05 mg/L rutin under the above conditions were 99.40 and 99.74%, respectively. The SOPM model proved to be powerful for navigating the design space. Under the above optimum conditions, the increased IRI was linearly related to the concentration of rutin in the range from 0.008 to 0.100 mg/L with the regression equation IRI = 1948.20c + 5.24 (r = 0.9994) and in the range from 0.100 to 1.000 mg/L with the regression equation IRI = 1362.50 c + 61.94 (r = 0.9996). The detection limit (3σ) was of 1.95 × 10^?3 mg/L. The sampling frequency of this method was 72/h. The method was used directly to determine rutin in tablets. Copyright © 2009 John Wiley & Sons, Ltd.     

Microflow injection potassium bioassay based on G‐quadruplex DNAzyme‐enhanced chemiluminescence

By taking advantage of microflow injection chemiluminescence analysis, we developed a distinctive microfluidic bioassay method based on G‐Quadruplex DNAzyme‐enhanced chemiluminescence for the determination of K⁺ in human serum. AGRO100, the G‐rich oligonucleotide with high hemin binding affinity was primarily selected as a K⁺ recognition element. In the presence of K⁺, AGRO100 folded into G‐quadruplex and bound hemin to form DNAzyme, which catalyzed the oxidation of luminol by H₂O₂ to produce chemiluminescence. The intensity of chemiluminescence increased with the K⁺ concentration. In the study, the DNAzyme showed both long‐term stability and high catalytic activity; other common cations at their physiological concentration did not cause notable interference. With only 6.7 × 10^?13 mol of AGRO100 consumption per sample, a linear response of K⁺ ranged from 1 to 300 µmol/L, the concentration detection limit 0.69 µmol/L (S/N = 3) and the absolute detection limit 1.38 × 10^?12 mol were obtained. The precision of 10 replicate measurements of 60 µmol/L K⁺ was found to be 1.72% (relative standard deviation). The accuracy of the method was demonstrated by analyzing real human serum samples. Copyright © 2014 John Wiley & Sons, Ltd.     

New luminol chemiluminescence reaction using diperiodatoargentate as oxidate for the determination of amikacin sulfate

A new chemiluminescence (CL) reaction between luminol and diperiodatoargentate {K₂ [Ag (H₂IO₆) (OH) ₂]} was observed in alkaline medium. The CL intensity could be greatly enhanced by amikacin sulfate. Therefore a new CL method for the determination of amikacin sulfate was built by combining with flow injection technology. A possible mechanism of the CL reaction was proposed via the investigation of the CL kinetic characteristics, the CL spectrum and the UV absorption spectra of some related substance. The concentration range of linear response was 5.1 × 10^?8 to 5.1 × 10^?6 mol L^?1 with a detection limit of 1.9 × 10^?8 mol L^?1 (3σ). The proposed method had good reproducibility with a relative standard deviation of 2.8% (n = 7) for 5.1 × 10^?7 mol L^?1 of amikacin sulfate. It was successfully applied to determine amikacin sulfate in serum. Copyright © 2009 John Wiley & Sons, Ltd.     

Chemiluminescence method for the determination of piroxicam by the enhancement of the tris‐(4,7‐diphenyl‐1,10‐phenanthrolinedisulphonic acid) ruthenium(II) (RuBPS)–cerium(IV) system and its application

A simple, rapid chemiluminescence (CL) method was described for the determination of piroxicam, a commonly used analgesic agent drug. A strong CL signal was detected when cerium(IV) sulphate was injected into tris‐(4,7‐diphenyl‐1,10‐phenanthrolinedisulphonic acid) ruthenium(II) (RuBPS)–piroxicam solution. The CL signal was proportional to the concentration of piroxicam in the range 2.8 × 10^–8–1.2 × 10^–5 mol/L. The detection limit was 2 × 10^–8 mol/L and the relative standard deviation (RSD) was 3.7% (c = 7.0 × 10^–7 mol/L piroxicam; n = 11). The proposed method was applied to the determination of piroxicam in pharmaceutical preparations in capsules, spiked serum and urine samples with satisfactory results. Copyright © 2008 John Wiley & Sons, Ltd.     

Flow‐injection chemiluminescence determination of diazepam by oxidation with N‐bromosuccinimide

A rapid and sensitive flow‐injection chemiluminescence (FI–CL) method is described for the determination of diazepam based on its reaction with N‐bromosuccinimide (NBS) in alkaline medium in the presence of dichlorofluorescein (DCF) as an effective energy‐transfer agent. Under optimum conditions, the proposed method allowed the measurement of diazepam over the range of 2.0 × 10^?6 to 2.0 × 10^?4 mol/L with a detection limit of 5.0 × 10^?7 mol/L. The relative standard deviation for 11 parallel measurements of 2.0 × 10^?5 mol/L diazepam was 2.1%. The method was applied satisfactorily for the determination of diazepam in pharmaceutical preparations, and the results agree well with those obtained by spectrophotometry. The use of the proposed system for the determination of diazepam in urine and plasma samples was also tested. The possible mechanism of the chemiluminescence reaction is discussed briefly. Copyright © 2012 John Wiley & Sons, Ltd.