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1.
N‐Acetyl‐L‐cysteine (NAC) can inhibit the luminol–H2O2, reaction, which is catalyzed by silver nanoparticles. Based on this phenomenon a new method was developed for NAC determination. Under optimum conditions, a linear relationship between chemiluminescence intensity and NAC concentration was found in the range 0.034–0.98 µg/mL. The detection limit was 0.010 µg/mL (S/N =3), and the relative standard deviation (RSD) was <5% for 0.480 µg/mL NAC (n =5). This simple, sensitive and inexpensive method has been applied to measure the concentration of NAC in pharmaceutical tablets. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
2.
Specific catalytic oxidation of oxymyoglobin (MbO(2)) and luminol by ferricyanide was studied in a flow-injection system. MbO(2) in different redox states (ferric and ferrous) was oxidized to Mb(Fe(III)) by ferricyanide, and then specific binding of the ferrocyanide anion to Mb(Fe(III)) to the His 119 (GH1) region accelerated the electron transfer between Mb(Fe(III)) and luminol, which produced a chemiluminescence (CL) signal at 425 nm. The increased CL emission was correlated with the myoglobin concentration in the range 0.16-7.5 microg/mL. Thermogravimetry and differential scanning calorimetry were used to investigate the temperature effects on this reaction. The results showed that the CL intensity in the presence of myoglobin changed considerably with heating in the range 15-50 degrees C, and the maximal CL intensity was observed at 40 degrees C, corresponding to the glass transition temperature of myoglobin. The effect of different ligands and interferences were also studied. 相似文献
3.
A simple and sensitive chemiluminescence (CL) method was developed for the determination of citalopram in pharmaceutical preparations and human plasma. The method is based on the enhancement of the weak CL signal of the luminol–H2O2 system. It was found that the CL signal arising from the reaction between alkaline luminol and H2O2 was greatly increased by the addition of silver nanoparticles in the presence of citalopram. Prepared silver nanoparticles (AgNPs) were characterized by UV–visible spectroscopy and transmission electron microscopy (TEM). Various experimental parameters affecting CL intensity were studied and optimized for the determination of citalopram. Under optimized experimental conditions, CL intensity was found to be proportional to the concentration of citalopram in the range 40–2500 ng/mL, with a correlation coefficient of 0.9997. The limit of detection (LOD) and limit of quantification (LOQ) of the devised method were 3.78 and 12.62 ng/mL, respectively. Furthermore, the developed method was found to have excellent reproducibility with a relative standard deviation (RSD) of 3.65% (n = 7). Potential interference by common excipients was also studied. The method was validated statistically using recovery studies and was successfully applied to the determination of citalopram in the pure form, in pharmaceutical preparations and in spiked human plasma samples. Percentage recoveries were found to range from 97.71 to 101.99% for the pure form, from 97.84 to 102.78% for pharmaceutical preparations and from 95.65 to 100.35% for spiked human plasma. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
4.
Yeoun Suk Suh Mohammad Kamruzzaman Al‐Mahmnur Alam Sang Hak Lee Young Ho Kim Gyu‐Man Kim Trung Dung Dang 《Luminescence》2014,29(3):248-253
A sensitive determination of a synthetic fluoroquinolone antibacterial agent, moxifloxacin (MOX), by an enhanced chemiluminescence (CL) method using a microfluidic chip is described. The microfluidic chip was fabricated by a soft‐lithographic procedure using polydimethyl siloxane (PDMS). The fabricated PDMS microfluidic chip had three‐inlet microchannels for introducing the sample, chemiluminescent reagent and oxidant, and a 500 µm wide, 250 µm deep and 82 mm long microchannel. An enhanced CL system, luminol–ferricyanide, was adopted to analyze the MOX concentration in a sample solution. CL light was emitted continuously after mixing luminol and ferricyanide in the presence of MOX on the PDMS microfluidic chip. The amount of MOX in the luminol–ferricyanide system influenced the intensity of the CL light. The linear range of MOX concentration was 0.14–55.0 ng/mL with a correlation coefficient of 0.9992. The limit of detection (LOD) and limit of quantification (LOQ) were 0.06 and 0.2 ng/mL respectively. The presented method afforded good reproducibility, with a relative standard deviation (RSD) of 1.05% for 10 ng/mL of MOX, and has been successfully applied for the determination of MOX in pharmaceutical and biological samples. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
5.
Together with flow injection analysis (FIA), a chemiluminescence (CL) fiber optic biosensor system has been developed for determining glutamine in animal cell cultures. Glutaminase (GAH) and glutamate oxidase (GLO) were onto separate porous aminopropyl glass beads via glutaraldehyde activation and packed to form an enzyme column. These two enzymes acted in sequence on glutamine to produce hydrogen peroxide, which was then reacted with luminol in the presence of ferricyanide to produce a light signal. An anion exchanger was introduced on-line to eliminate interfering endogenous glutamate in view of its negative charge at pH above 3.22 (isoelectric pH). Among several resins tested, the acetate form was most effective, and this type of ion exchanger also effectively adsorbed uric acid, acetaminophen, and aspartic acid.There was an excellent linear relationship between the CL response and standard glutamine concentration in the range 1 to 100 muM. A complete analysis could be performed in 2 min, including sampling and washing with a good reproducibility (+/- 4.4%). Both the bi-enzymic and ion exchange columns were useful for at least 500 analyses when the biosensor system was applied for the glutamine determination in murine hybridoma cell cultures and insect cell cultures. The values obtained compared well with those of HPLC, thus validating the applicability of the CL fiber optic system. (c) 1993 John Wiley & Sons, Inc. 相似文献
6.
A determination method for Co(II), Fe(II) and Cr(III) ions by luminol‐H2O2 system using chelating reagents is presented. A metal ion‐chelating ligand complex with a Co(II) ion and a chelating reagent like ethylenediaminetetraacetic acid (EDTA) produced highly enhanced chemiluminescence (CL) intensity as well as longer lifetime in the luminol‐H2O2 system compared to metals that exist as free ions. Whereas free Cu(II) and Pb(II) ions had a strong catalytic effect on the luminol‐H2O2 system, significantly, the complexes of Cu(II) and Pb(II) with chelating reagents lost their catalytic activity due to the chelating reagents acting as masking agents. Based on the observed phenomenon, it was possible to determine Co(II), Fe(II) and Cr(III) ions with enhanced sensitivity and selectivity using the chelating reagents of the luminol‐H2O2 system. The effects of ligand, H2O2 concentration, pH, buffer solution and concentrations of chelating reagents on CL intensity of the luminol‐H2O2 system were investigated and optimized for the determination of Co(II), Fe(II) and Cr(III) ions. Under optimized conditions, the calibration curve of metal ions was linear over the range of 2.0 × 10‐8 to 2.0 × 10‐5 M for Co(II), 1.0 × 10‐7 to 2.0 × 10‐5 M for Fe (II) and 2.0 × 10‐7 to 1.0 × 10‐4 M for Cr(III). Limits of detection (3σ/s) were 1.2 × 10‐8, 4.0 × 10‐8 and 1.2 × 10‐7 M for Co(II), Fe(II) and Cr(III), respectively. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
7.
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%. 相似文献
8.
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. 相似文献
9.
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. 相似文献
10.
Rapid determination of isoamyl nitrite in pharmaceutical preparations by flow injection analysis with on‐line UV irradiation and luminol chemiluminescence detection 
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下载免费PDF全文 Naoya Kishikawa Naoko Kondo Abena Amponsaa‐Karikari Hitoshi Kodamatani Kaname Ohyama Kenichiro Nakashima Shigeo Yamazaki Naotaka Kuroda 《Luminescence》2014,29(1):8-12
Isoamyl nitrite is used as a therapeutic reagent for cardiac angina and as an antidote for cyanide poisoning, but it is abused because of its euphoric properties. Therefore, a method to determine isoamyl nitrite is required in many fields, including pharmaceutical and forensic studies. In this study, a simple, rapid and sensitive method for the determination of isoamyl nitrite was developed using a flow injection analysis system equipped with a chemiluminescence detector and on‐line photoreactor. This method is based on on‐line ultraviolet irradiation of isoamyl nitrite and subsequent luminol chemiluminescence detection without the addition of an oxidant. A linear standard curve was obtained up to 1.0 μM of isoamyl nitrite with a detection limit (blank + 3SD) of 0.03 μM. The method was successfully applied to determine isoamyl nitrite content in pharmaceutical preparations. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
11.
Shifeng Li Huimin Sun Dong Wang Jianguo Hong Shanjun Tao Haiyin Yu Xiuhua Wang Xianwen Wei 《Luminescence》2012,27(3):211-216
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. 相似文献
12.
André R. T. S. Araujo Fernando Maya M. Lúcia M. F. S. Saraiva José L. F. C. Lima José M. Estela Víctor Cerdà 《Luminescence》2011,26(6):571-578
In this work, an automated flow‐based procedure for the screening of the effect of the different phenolic compounds on the chemiluminescence (CL) luminol–hydrogen peroxide–horseradish peroxidase (HRP) system is presented. This procedure involves the combination of multisyringe flow injection analysis (MFSIA) and sequential injection analysis (SIA) techniques and exploits the ability of the different subgroups of phenols, such as cholorophenols, nitrophenols, methylphenols and polyphenols, to enhance or inhibit the described CL system. The implementation of this reaction in the SIA–MSFIA system enabled favourable and precise conditions to evaluate the effect of phenolic compounds, as it involves an in‐line reaction between the phenolic derivative, hydrogen peroxide and peroxidase and subsequent oxidized HRP intermediates generation prior to the fast reaction with the chemiluminogenic reagent. Several studies were then performed with the aim of establishing the appropriate flow system configuration and reaction conditions. It was shown that phenol and chlorophenols produce an enhanced CL response and nitrophenols, methylphenols and polyphenols are inhibitors within the range of concentrations studied (1–100 mg/L). Based on these studies, the developed method was applied to the determination of total polyphenol and phenol content in wine/grape seeds and water samples, respectively, and the results obtained showed good agreement with those furnished by the corresponding Folin–Ciocalteu and 4‐aminoantipyrine reference methods. The developed approach is further pursued by designing an automated generic tool for performing studies of peroxidase‐catalysed CL reactions of luminol focused on the detection of compounds that will affect the rate of those reactions. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
13.
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. 相似文献
14.
A new flow injection chemiluminescence (CL) method has been developed for the determination of bisphenol A (BPA), based on the inhibitory effect of BPA on the chemiluminescence reaction between luminol and potassium hexacyanoferrate. Under optimum conditions, the decrease in CL emission intensity was linear with BPA concentration in the range 8.0 x 10(-7)-1.2 x 10(-5) mol/L, and the detection limit was 3.1 x 10(-7) mol/L. The relative standard deviation (RSD) of 11 replicate measurements was 2.6% for 2.0 x 10(-6) mol/L BPA (n = 11). The sampling frequency was calculated to be ca. 120/h. This method has been successfully used to determine the content of BPA in aqueous solution of polycarbonate materials. A brief discussion on the possible chemiluminescence reaction mechanism is presented. 相似文献
15.
A simple and sensitive flow‐injection (FI) method for the determination of nitrate and nitrite in natural waters, based on luminol chemiluminescence (CL) detection, is reported. Nitrate was reduced online to nitrite via a copperized cadmium (Cu–Cd) column and then reacted with acidic hydrogen peroxide to form peroxynitrous acid. CL emission was observed from the oxidation of luminol in an alkaline medium in the presence of the peroxynitrite anion. The limits of detection (S:N = 3) were 0.02 and 0.01 µg N/L, with sample throughputs of 40 and 90 /h for nitrate and nitrite, respectively. Calibration graphs were linear over the range 0.02–50 and 0.01–50 µg N/L [R2 = 0.9984 (n = 8) and R2 = 0.9965 (n = 7)] for nitrate and nitrite, respectively, with relative standard deviations (RSDs; n = 3) in the range 1.8–4.6%. The key chemical and physical variables (reagent concentrations, buffer pH, flow rates, sample volume, Cu–Cd reductor column length) were optimized and potential interferences investigated. The effect of cations [Ca(II), Mg(II), Co(II), Fe(II) and Cu(II)] was masked online with EDTA. Common anions (PO43?, SO42? and HCO3?) did not interfere at their maximum admissible concentrations in freshwaters. The effect of salinity on the luminol CL reaction with and without nitrate and nitrite (2 and 0.5 µg N/L, respectively) was also investigated. The method was successfully applied to freshwaters and the results obtained were in good agreement with those obtained by an automated segmented flow analyser reference method. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
16.
Platinum colloids prepared by the reduction of hexachloroplatinic acid with citrate in the presence of different stabilizers were found to enhance the chemiluminescence (CL) of the luminol-H(2)O(2) system, and the most intensive CL signals were obtained with citrate-protected Pt colloids synthesized with citrate as both a reductant and a stabilizer. Light emission was intense and reproducible. Transmission electron microscopy and X-ray photoelectron spectroscopy studies were conducted before and after the CL reaction to investigate the possible CL enhancement mechanism. It is suggested that this CL enhancement is attributed to the catalysis of platinum nanoparticles, which could accelerate the electron-transfer process and facilitate the CL radical generation in aqueous solution. The effects of Pt colloids prepared by the hydroborate reduction were also investigated. The application of the luminol-H(2)O(2)-Pt colloids system was exploited for the determination of compounds such as uric acid, ascorbic acid, phenols and amino acids. 相似文献
17.
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. 相似文献
18.
《Luminescence》2003,18(3):162-172
The reaction of iron(III) tetrakis‐5,10,15,20‐(N‐methyl‐4‐pyridyl)porphyrin (Fe(III)TMPyP) with hydrogen peroxide (H2O2) and the catalytic activity of the reaction intermediates on the luminescent peroxidation of luminol in aqueous solution were studied by using a double‐mixing stopped‐flow system. The observed luminescence intensities showed biphasic decay depending on the conditions. The initial flashlight decayed within <1 s followed by a sustained emission for more than 30 s. Computer deconvolution of the time‐resolved absorption spectra under the same conditions revealed that the initial flashlight appeared during the formation of the oxo–iron(IV) porphyrin, TMPyPFe(IV) = O, which is responsible for the sustained emission. The absorption spectra 0.0–0.5 s did not reproduce well by a simple combination of the two spectra of Fe(III)TMPyP and TMPyPFe(IV) = O, indicating that transient species was formed at the initial stage. Addition of uric acid (UA) caused a significant delay in the initiation of the luminol emission as well as in the formation of the TMPyPFe(IV) = O. Both of them were completely diminished in the presence of UA equimolar with H2O2, while mannitol had no effect at all. The delay of the light emission as well as the appearance of TMPyPFe(IV) = O was directly proportional to the [UA]0 but other kinetic profiles were not changed significantly. Based on these observations and the kinetic analysis, we confirmed the involvement of the oxo–iron(IV) porphyrin radical cation, (TMPyP)·+Fe(IV) = O, as an obligatory intermediate in the rate‐determining step of the overall reaction, Fe(III)TMPyP + H2O2 → TMPyPFe(IV) = O, with a rate constant of k = 4.3 × 104/mol/L/s. The rate constants for the reaction between the (TMPyP)·+Fe(IV) = O and luminol, and between the TMPyPFe(IV) = O and luminol were estimated to be 3.6 × 106/mol/L/s and 1.31 × 104/mol/L/s, respectively. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
19.
Two novel sensitive sequential injection chemiluminescence analysis and fluorescence methods for trovafloxacin mesylate detection have been developed. The methods were based on the enhancement effect of gold nanoparticles on luminol–ferricyanide–trovafloxacin and europium(III)–trovafloxacin complex systems. The optimum conditions for both detection methods were investigated. The chemiluminescence signal was emitted due to the enhanced effect of gold nanoparticles on the reaction of luminol–ferricyanide–trovafloxacin in an alkaline medium. The response was linear over a concentration range of 1.0 × 10–9 to 1.0 × 10–2 mol/L (%RSD = 1.3), (n = 9, r = 0.9991) with a detection limit of 1.7 × 10–10 mol/L (S/N = 3). The weak fluorescence intensity signal of the oxidation complex of europium(III)–trovafloxacin was strongly enhanced by gold nanoparticles and detected at λex = 330 and λem = 540 nm. Fluorescence detection enabled the determination of trovafloxacin mesylate over a linear range of 1.0 × 10–8 to 1.0 × 10–3 mol/L (%RSD = 1.2), (n = 6, r = 0.9993) with a detection limit of 3.3 × 10–9 mol/L. The proposed methods were successfully applied to the determination of the studied drug in its bulk form and in pharmaceutical preparations. The results were treated statistically and compared with those obtained from other reported methods. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
20.
A flow injection chemiluminescence method is described for the determination of subnanomolar concentrations of vanadium in environmental water samples. The procedure is based on the oxidation of luminol in the presence of dissolved oxygen catalyzed by vanadium(IV). Vanadium(V) reduction and preconcentration of vanadium(IV) was carried out using in‐line silver reductor and 8‐hydroxyquinoline chelating columns at pH 3.15, respectively. The calibration graph for vanadium(IV) was linear in the concentration range of 0.025–10 µg/L with relative standard deviation in the range of 0.4–5.58%. The detection limit (3s blank) was 3.8 × 10?3 µg/L without preconcentration; when the vanadium(IV) was preconcentrated with an 8‐HQ column for 1 min (2.0 mL of sample loaded), the detection limit of 5.1 × 10?4 µg/L was achieved. One analytical cycle can be completed in 2.0 min. The analysis of certified reference materials (CASS‐4, NASS‐5 and SLRS‐4) by the proposed method showed good agreement with the certified values. The method was successfully applied to the determination of total dissolved vanadium in environmental water samples. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献