共查询到20条相似文献,搜索用时 15 毫秒
1.
A chemiluminescent method using flow injection is described for the determination of cefadroxil monohydrate. The method is based on the chemiluminescence reaction of cefadroxil with potassium permanganate in sulphuric acid, sensitized by quinine. The proposed procedure allows the determination of cefadroxil over the concentration range 0.1-30 mug ml(-1) with a detection limit of 0.05 mug ml(-1) and a sample measurement frequency of 150 samples h(-1). The method was successfully applied to the determination of cefadroxil in pharmaceutical preparations and biological fluids. 相似文献
2.
Carmen Gómez-Benito Sagrario Torres-Cartas 《International journal of environmental analytical chemistry》2013,93(2):152-165
In this work, a sensitive flow injection chemiluminescence (FI-CL) method for the determination of nematicide Fenamiphos in a rapid and simple way is proposed. Fenamiphos is first photodegraded in basic medium. These photofragments react with Ce(IV) providing the chemiluminescence signal. To the authors’ knowledge, no chemiluminescence method has been described in the literature for the determination of the nematicide Fenamiphos. All physical and chemical parameters in the flow injection chemiluminescence system were optimized in order to obtain the best sensitivity, selectivity and sample throughput. Before the injection of the sample in the FI-CL system, a preconcentration step with solid phase extraction C18 cartridges was performed. By applying solid phase extraction (SPE) to 250?mL of standard (final volume 10?mL), the linear dynamic range was between 3.4 and 60?µg?L?1, and the detection limit was 1?µg?L?1. When SPE was applied to 500?mL of standard (final volume 10?mL), the detection limit was 0.5?µg?L?1. These detection limits are below the emission limit value established by the Spanish Regulations of the Hydraulic Public Domain for pesticides (50?µg?L?1) and of the same order as the limit established for total pesticides (0.5?µg?L?1) at European Directive on the quality of water for human consumption. The sample throughput was 126 hour?1. Intraday and interday coefficients of variation were below 10% in all cases. No interference was registered in presence of usual concentrations of anions, cations and other organophosphorus pesticides. The method was successfully applied to the analysis of environmental water samples, obtaining recoveries between 96 and 107.5%. 相似文献
3.
The solid-phase chemiluminescence analysis of gold on the surface of an anion-exchange resin was studied. A method for the fast determination of gold using flow injection was established. The anion-exchange resin was used as an adsorbent of gold ion in the form of AuCl4-. The cation-exchange resin was used for the on-line separation of cations in the matrix. To obtain the best results, the preconcentration and separation conditions, chemiluminescence conditions, interfering ions and their elimination conditions were optimized. The linear range of the calibration curve of AuCl4- is from 0 microg ml(-1) to 5.00 microg ml(-1). The detection limit of AuCl4- is 0.012 microg ml(-1). The method has been used for the determination of gold in geological samples (standard ores). The results are in agreement with certified value of gold standard samples with relative standard deviation from 2.22% to 8.97%. Through the use of flow injection, the preconcentration and separation can be performed automatically. 相似文献
4.
A simple, sensitive and rapid flow-injection chemiluminescence method has been developed for the determination of ferulic acid based on the chemiluminescence reaction of ferulic acid with potassium permanganate in a nitric acid medium. A strong chemiluminescence signal was observed when ferulic acid was injected into an acidic potassium permanganate solution in a flow-cell. The present method allowed the determination of ferulic acid in the concentration range of 6.0 x 10(-6) to 2.0 x 10(-4) mol l(-1); the detection limit (3sigma) for ferulic acid was 9.6 x 10(-8) mol l(-1). The relative standard deviation was 1.0% for 11 replicate analyses of 2.0 x 10(-4) mol l(-1) ferulic acid. The proposed method was applied to the determination of ferulic acid in real samples with satisfactory results. Moreover, the reaction mechanism of the chemiluminescence system was primarily considered. 相似文献
5.
A chemiluminescent method using flow injection is described for the determination of pyridoxine hydrochloride. Its detection limit, linearity and reproducibility were examined. The method is based on the enhancing effect of pyridoxine hydrochloride on the chemiluminescence generated by the oxidation of luminol with hydrogen peroxide in aqueous potassium hydroxide and sodium oxalate. The proposed method is simple and inexpensive. The chemiluminescence intensity is a linear function of pyridoxine hydrochloride concentration over the range 10–250 μg ml−1 with a detection limit of 6 μg ml−1. The applicability of the method was demonstrated by the determination of pyridoxine hydrochloride in different tablet formulations and some dietary sources. 相似文献
6.
A flow injection chemiluminescence method was described for the determination of four phenothiazine drugs, namely, chlorpromazine hydrochloride, perphenazine hydrochloride, fluphenazine hydrochloride and thioridazine hydrochloride. Strong Chemiluminescence (CL) signal was produced when above-mentioned drug was injected into the mixed stream of luminol with KMnO4. The linear ranges of the method were 0.0020-1.0 μg/mL chlorpromazine hydrochloride, 0.0040-3.0 μg/mL perphenazine hydrochloride, 0.0020-5.0 μg/mL fluphenazine hydrochloride and 0.0050-1.0 μg/mL thioridazine hydrochloride. The detection limits were 0.4 ng/mL chlorpromazine hydrochloride, 0.7 ng/mL perphenazine hydrochloride, 2 ng/mL fluphenazine hydrochloride and 0.7 ng/mL thioridazine hydrochloride. The proposed method was applied to the determination of chlorpromazine hydrochloride in injections and in mental patient's urine samples and the satisfactory results were achieved. The possible CL reaction mechanism was also discussed briefly. 相似文献
7.
Ivanise Gaubeur Lúcia Helena S Avila-Terra Jorge C Masini Maria Encarnación V Suárez-Iha 《Analytical sciences》2007,23(10):1227-1231
Zinc ions form a yellow complex with di-2-pyridyl ketone salicyloylhydrazone (DPKSH). This complex showed maximum absorption at 376 nm, and it was used to develop spectrophotometric flow injection methods for Zn(II) determination in different samples. Two types of flow systems were proposed. In the first system, a linear analytical curve was obtained in a concentration range from 0.217 to 4.60 mg L(-1) Zn(II), with a detection limit of 48.8 microg L(-1). In the second system, a minicolumn packed with an anion exchanger resin was used to concentrate Zn(II) as a chlorocomplex, and a linear analytical curve within a concentration range from 0.0824 to 2.06 mg L(-1) Zn(II) was obtained, having a detection limit of 13.9 microg L(-1). The developed methods were applied to biological and pharmaceutical samples, and a great compliance was observed by comparing the results with ones obtained by an atomic absorption technique. 相似文献
8.
Fundamentals of ion-pair flow injection with piezoelectric detection were investigated experimentally and theoretically for the adsorption of dodecyl phenylsulfonate and interfacial ion-pair formation with epinephrine and l-dopa on silver electrode of quartz crystal microbalance. The influences of sulfonate concentration and operating parameters on the frequency response were demonstrated and provided the possibility for the discriminating determination of mixtures. The selected system of ion-pair flow injection with piezoelectric detection was applied to the determination of epinephrine and l-dopa. Calibration curves were linear in ranges 4.00-850 and 3.50-730 mug ml(-1), with detection limits of 1.22 and 1.05 mug ml(-1) and sampling frequencies of 120 samples h(-1), for epinephrine and l-dopa, respectively. The method has been satisfactorily applied to the determination of catecholamines in pharmaceutical preparations. 相似文献
9.
Choiwan Lau 《Analytica chimica acta》2004,514(1):45-49
A simple and convenient flow injection-chemiluminescence (FI-CL) method for the determination of cysteine is reported, based on a fast and strong CL in a basic luminol-cysteine-NaIO4 solution. The linear range was 1.0×10−8 to 1.0×10−6 M with a detection limit (3s) of 5×10−9 M, which was 100 times more sensitive than previously reported CL methods. Singlet oxygen, hydroxyl radical and hydrogen peroxide were suggested to be produced in this reaction and were responsible for the CL of cysteine. This simple method has been successfully applied for the determination of cysteine in a pharmaceutical formulation. 相似文献
10.
Based on the chemiluminescence (CL) emission generated from the oxidation of ceftriaxone sodium alkali hydrolysate by potassium permanganate in polyphosphoric acid (PPA), a novel determination method for ceftriaxone sodium was developed by using a flow-injection technique. The calibration curve appears to be linear in the range between 0.05 and 100 microg mL(-1) with a detection limit (3sigma) of 25 ng mL(-1), and a relative standard deviation (RSD) of 0.6% for eleven replicate determinations of 5.0 microg mL(-1) ceftriaxone sodium. The proposed method has been successfully utilized for the determination of ceftriaxone sodium in pharmaceutical formulations, while the chemiluminescence reaction mechanisms were investigated. 相似文献
11.
12.
R. Escobar M. S. García-Domínguez A. Guiraúm F. F. de la Rosa 《Analytical and bioanalytical chemistry》1998,361(5):509-511
A flow injection (FI) chemiluminescence method for the determination of Cr(III) in blood serum, urine and hair samples is reported. It is based on the chromium-catalyzed light emission from the luminol oxidation by hydrogen peroxide. The apparatus consists of an FI system with a flow cell formed by a coiled transparent tube suitable for chemiluminescence detection. The specificity of the method is achieved in presence of EDTA. The detection limit under optimum conditions is 0.01 μg L–1 of Cr(III). Precision and accuracy were evaluated by determining Cr(III) concentrations in urine standards from the National Institute of Standard and Technology (NIST). 相似文献
13.
R. Escobar M. S. García-Domínguez A. Guiraúm F. F. de la Rosa 《Fresenius' Journal of Analytical Chemistry》1998,361(5):509-511
A flow injection (FI) chemiluminescence method for the determination of Cr(III) in blood serum, urine and hair samples is
reported. It is based on the chromium-catalyzed light emission from the luminol oxidation by hydrogen peroxide. The apparatus
consists of an FI system with a flow cell formed by a coiled transparent tube suitable for chemiluminescence detection. The
specificity of the method is achieved in presence of EDTA. The detection limit under optimum conditions is 0.01 μg L–1 of Cr(III). Precision and accuracy were evaluated by determining Cr(III) concentrations in urine standards from the National
Institute of Standard and Technology (NIST).
Received: 30 June 1997 / Revised: 16 January 1998 / Accepted: 23 January 1998 相似文献
14.
Tiago de Jesus Guedes Morgana F. Alecrim Fernando M. Oliveira Amanda B. Lima Sandro L. Barbosa Wallans T. P. dos Santos 《Journal of Solid State Electrochemistry》2016,20(9):2445-2451
This work describes the development of a simple, fast and low-cost method for determining prazosin (PRA) in pharmaceutical samples by flow injection analysis with multiple-pulse amperometric (FIA-MPA) detection using a boron-doped diamond film electrode. Electrochemical detection of PRA was optimized in phosphate buffer pH 4.0 by cyclic voltammetry, in which PRA presented two oxidation processes around at 0.97 and 1.40 V versus Ag/AgCl (3.0 mol L?1 KCl). In these conditions, PRA also showed one reduction process at ?0.75 V that is dependent on the oxidation processes. Thus, the determination of PRA by FIA-MPA detection consisted on the application of a two-potential waveform, E 1 (generator potential)?=?1.6 V/400 ms and E 2 (collector potential)?=??1.0 V/30 ms, with sample loop of 150 μL and flow rate of 3.0 mL min?1. The method showed good repeatability (RSD?<?3.0 %) and high analytical frequency (70 injections per h). The working linear range was obtained from 2 to 200 μmol L?1 with a limit of detection of 0.5 μmol L?1. The recovery tests in all samples were approximately 100 %, and the results were compared with chromatographic methods. 相似文献
15.
A new flow injection procedure for an assay of Fe(III) by using salicylate obtained from antipyretic powder, which is a cheap and easily available reagent, is proposed. A red complex was continuously monitored by a laboratory-made green LED colorimeter. A linear calibration was obtained in the range of 1–20 mg Fe l−1 with a detection limit of 0.5 mg Fe l−1 and R.S.D.s of 1.4–5.4% (n=3, for 1–20 mg Fe l−1). The new procedure was applied to assay iron contents in pharmaceutical preparations. The results were in good agreement with those of the USP standard method. 相似文献
16.
H. Lingeman J. A. Haverhals H. J. E. M. Reeuwijk U. R. Tjaden J. van der Greef 《Chromatographia》1987,24(1):886-890
Summary Dobutamine is one of the synthetic catecholamines acting directly onβ
1-receptors. For the analysis of dobutamine in rat plasma samples, a selective and sensitive liquid chromatographic method
is described. After a simple liquid-liquid extraction, separation of the analyte was performed using a reversed-phase ion-pair
system with an octyl modified silica column. The solute was detected by fluorescence detection, applying an excitation wavelength
of 285nm and an emission wavelength of 313nm. The (im)possibilities of the application of the normally used assays for the
isolation, concentration and quantitation of catecholamines are discussed. By the addition of a minimum amount of modifier
to the mobile phase, the selectivity of the system was increased significantly. With this method the detection limit is 9ng/ml
in 0.2ml plasma samples. The application of the method is shown in rat plasma samples by measuring the concentration-time
curves to establish plasma level-effect relationships for this drug. 相似文献
17.
Sensitive and rapid chemiluminescence enzyme immunoassay for microcystin-LR in water samples 总被引:1,自引:0,他引:1
A highly sensitive, specific, simple, and rapid chemiluminescence enzyme immunoassay (CLEIA) was developed for the determination of microcystin-LR (MC-LR). Several physicochemical parameters such as the chemiluminescent assay mediums, the dilution ratio of MC-LR-OVA conjugate, monoclonal antibody concentration, and peroxidase labeled antibody concentration were studied and optimized. Under optimum conditions, calibration curve obtained for MC-LR had detection limits of 0.032 ± 0.003 μg L−1, the 50% inhibition concentration (IC50) was 0.20 ± 0.02 μg L−1 and the quantitative detection range was 0.062-0.65 μg L−1. The proposed methods was successfully applied to the monitoring of MC-LR in spiked water samples without significant effect of the matrix, and the recovery of MC-LR added to water samples at different concentrations ranged from 80% to 115% with the coefficients of variation (CVs) less than 9%. The LOD attained from the calibration curves and the results obtained for the real samples demonstrate the potential use of CLEIA as a screening tool for the analysis of MC-LR in environmental samples. 相似文献
18.
A novel chemiluminescence gas-diffusion flow injection system for the determination of arsenic(III) in aqueous samples is described. The analytical procedure involves injection of arsenic(III) samples and standards into a 0.3 mol L−1 hydrochloric acid carrier stream which is merged with a reagent stream containing 0.2% (w/v) sodium borohydride and 0.015 mol L−1 sodium hydroxide. Arsine, generated in the combined carrier/reagent donor stream, diffuses across the hydrophobic Teflon membrane of the gas-diffusion cell into an argon acceptor stream and then reacts with ozone in the flow-through chemiluminescence measuring cell of the flow system. Under optimal conditions, the method is characterized by a wide linear calibration range from 0.6 μg L−1 to 25 mg L−1, a detection limit of 0.6 μg L−1 and a sample throughput of 300 samples per hour at 25 mg L−1 and 450 samples per hour at 25 μg L−1. 相似文献
19.