首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
《Analytical letters》2012,45(13):2487-2502
Abstract

A glassy carbon electrode plus Methylene blue as a mediator was employed to study and sense the electrocatalytic oxidation of phenothiazines, including chlorpromazine, perphenazine, promazine, and fluphenazine, using cyclic voltammetry and chronoamperometry as diagnostic techniques. The electron-transfer coefficient, alpha (= 0.45), for phenothiazines compounds at the surface of glassy carbon electrode was determined using a cyclic voltammetry technique. It was found that under a selected pH (8.6) the peak current due to the oxidation of Methylene blue at the surface of the electrode that occurrs at a potential of about ? 180 mV is proportional to the phenothiazines concentration. Linear analytical curves were obtained in the ranges of 1.0 × 10?6 ? 2.1 × 10?4 mol L?1 for the phenothiazines compounds. The influences of potentially interfering substances on the current response of the system were examined. The method was used for the determination of phenothiazines compounds, including chlorpromazine, perphenazine, promazine, and fluphenazine in human.  相似文献   

2.
《Analytical letters》2012,45(5):789-805
Abstract

Three 2,10‐disubstituted phenothiazines—chlorpromazine hydrochloride (CPM), thioridazine hydrochloride (TR) and propericiazine (PRC)—were electrochemically studied in various buffer systems at different pH values, using a glassy carbon electrode. The substances were electrochemically oxidized at potential range 0.55–0.75 V. The oxidation was reversible and exhibited diffusion‐controlled process. The mechanism of the oxidation process is discussed. According to the linear relation between peak current and concentration, differential pulse voltammetry (DPV) and square wave voltammetry (SWV) methods for quantitative determination of chlorpromazine and propericiazine in 0.1 M HClO4, and thioridazine in pH 2 phosphate buffer, was applied. Both the repeatability and reproducibility of the methods were also determined for all studied substances. The developed procedures were successfully applied to the determination of chlorpromazine and thioridazine in pharmaceutical dosage forms.  相似文献   

3.
《Analytical letters》2012,45(13):2353-2363
Abstract

A flow-injection method is proposed for the determination of chlorpromazine and other N-substituted phenothiazines. The procedure is based on the oxidation of analyte with lead dioxide entrapped into polymeric material in a packed-bed reactor. The oxidation of the drug yields soluble Pb2-, which is monitored by means of the lead ion selective electrode in the wall-jet configuration. The calibration graph is linear over the range of 0.01 – 2 μg ml?1 of chlorpromazine with relative standard deviation of 1.4% and sample throughput 20 h?1. The developed method was applied to the determination of chlorpromazine in pharmaceutical preparations.  相似文献   

4.
《Analytical letters》2012,45(12):1933-1941
Abstract

A rapid and simple flow‐injection chemiluminescence (CL) method is described for the determination of perphenazine, which is based on the CL intensity that generated from the redox reaction of Ce (IV)-perphenazine in HNO3 medium is proportional to the perphenazine concentration without any sensitizers. The proposed method allows the determination range within 1.0×10?7–7.0 ×10?5 g mL?1 with a detection limit of 8.0×10?8 g mL?1, and it has been successfully applied to the determination of the perphenazine in pharmaceutical tablet compared well with the official method.  相似文献   

5.
Yinhuan Li  Weifen Niu 《Talanta》2007,71(3):1124-1129
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   

6.
The oxidation of 1,1,3-tricyano-2-amino-1-propene in the presence of hydrogen peroxide and copper is favored by imidazole, 4-methylimidazole, or any other compound possessing the imidazole ring. This fluorescent reaction has been used for the individual determination of imidazole and 4-methylimidazole at 10−5M level by application of several kinetic methods (tangent, fixed-time, and maximum fluorescence intensity) with a precision (%RSD) of about ±1%. A differential-rate principle allows the determination of binary mixtures of both compounds, which is subject to synergistic effects. Mixtures of imidazole and 4-methylimidazole in ratios between 1:1 and 1:9 have been resolved with a %RSD of ±7.1% for imidazole and ±3.1% for 4-methylimidazole.  相似文献   

7.
结合流动注射进样技术,借助时间扫描荧光方式,建立了流动注射在线氧化荧光分析法测定吩噻嗪类药物的新方法。在优化的实验条件下,盐酸氯丙嗪、奋乃静、盐酸异丙嗪的质量浓度分别在0.12~36、0.4~20、0.4~36 mg/L范围内与荧光强度呈良好的线性关系,方法检出限分别为0.003 6、0.02、0.03 mg/L。该方法简便、快速、准确、灵敏度高,用于药物制剂、尿样中吩噻嗪类药物的直接测定,结果满意。  相似文献   

8.
《Analytical letters》2012,45(4):929-949
Abstract

The principal aim of this research was the standardization of a spectrophotometric method using the reaction with ferric ion for quantitative determination of these substances in pharmaceutical preparations. By reaction with ferric ion chlorpromazine gave a pink compound with maximum absorption at 525 nm. the violet product obtained by the reaction with ferric ion and levomepromazine had a maximum at 565 nm. Beer's law was obeyed in a wide range of concentrations for both compounds. the method was applied to simulated and commercially available samples. the efficiency of the method was confirmed by recovery tests.  相似文献   

9.
《Analytical letters》2012,45(14):2491-2501
Abstract

Fluorescence spectroscopy was applied to the development of a sensitive and simple method for the determination of chlorpromazine HCl and thioridazine-HCl. The method is based upon development of an intense fluorescence using N-bromosuccinimide as the fluorogenic reagent. The produced fluorescence has very characteristic excitation and emission spectra and was stable for at least one hour. The results were reproducible and as little as 5 ng/ml chloropromazine HCl and 1 ng/ml thioridazine-HCl could be determined. The method was applied successfully to the analysis of various commercially available dosage forms. The obtained results were in good agreement with those of the official BP 93 procedures.  相似文献   

10.
Abstract

A rapid, precise, and accurate high performance liquid chromatographic procedure is presented for the simultaneous determination of amitriptyline hydrochloride and perphenazine in two component tablet formulations. The related compounds of amitriptyline hydrochloride were separated, making the determination specific for amitriptyline hydrochloride and perphenazine. The method was used for the assay and content uniformity for three commercial products. The mobile phase was 0.02 M ammonium acetate in aceto-nitrile: methanol: water (45:15:40) solution and the pH was adjusted to 5.0 by acetic acid. The column was a supelcosil (5 μm) LC-8-DB (250 mm × 4.6 mm i. d). The method was tested for linearity, recovery, and specificity.  相似文献   

11.
《Analytical letters》2012,45(6):1485-1498
Abstract

A new, sensitive colorimetric method has been described for the quantitative determination of six N-substituted phenothiazines. the method depends on the formation of stable phenothiazine free radical by the use of 2-iodoxybenzoate as chromogenic reagent. the drug in 50% sulphuric acid is treated with reagent (5×10?4 M). the produced red or purple color possesses characteristic absorption maximum for each of the drugs tested. Beer's law is obeyed over the concentration range 2-30 μg.ml?1 with apparent molar absorptivities ranging from 9.4-12.4×10?3 for the studied phenothiazine derivatives. the average % recovery is 99.5±0.96 - 101.6±1.01. the method was applied successfully to the microdetermination of promazine. HCl, chlorpromazine, HCl, promethazine. HCl, perphenazine, levomepromazine HCl and mesoridazine besylate either in pure form or incorporated in their representative pharmaceutical preparations. the stoichiometry of the reaction was assumed and a reaction mechanism was suggested. the precision of the assay was comparable with the official ones.  相似文献   

12.
The fluorescence characteristics of 1,1,3-tricyano-2-amino-1-propene (TRIAP) as an analytical reagent and a kinetic-fluorometric method for determination of histidinol are described. The method is based on the accelerating effect of histidinol on the oxidation of TRIAP by hydrogen peroxide in the presence of copper. The chemical reaction is monitored by measuring the rate of change of the fluorescence intensity. Histidinol can be determined by various kinetic methods (initial-rate, fixed-time, maximum fluorescence intensity, and variable-time) in the range 10−5 to 10−4 M.  相似文献   

13.
《Analytical letters》2012,45(9):1743-1756
Abstract

The fluorescence enhancement and solvent effect of Eu-dibenzoylmethane-ammonia system was studied. The fluorescence intensity of the system can be greatly increased by y3+. The maximum fluorescence intensity was obtained at pH 8.9 – 9.5. The fluorescence intensity is a linear function of Eu2+ in the range of 1.0x10?9 M -4.0x10?8 M. The detection limit is 1.1x10?10 M. The optimized procedure is applied to the determination of europium in lanthanide oxide samples.  相似文献   

14.
《Analytical letters》2012,45(8):1555-1566
ABSTRACT

The use of 1, 10-phenantroline as internal standard (IS) is proposed for spectrophotometric determination of chlorpromazine hydrochloride in pharmaceutical formulations. The spectra of both compounds: analyte and internal standard are partially overlapped, so the Savitzky-Golay alghoritm was used to obtain separated signals of analyte and IS. The best parameters to generate the second-derivative spectra were: ∠λ = 10 nm (5 experimental points) and second polynomial degree. For quantification of chlorpromazine in pharmaceuticals, the zero-crossing technique was used. The values of the second-derivative peaks were measured for chlorpromazine at 256 nm and at 236 nm for IS. Analytical characteristic for proposed method was evaluated (r2=0.9990, detection limit=3.97 ng/ml). The obtained analytical results were in good agreement with results obtained using the UV-spectrophotometric Blazek method.  相似文献   

15.
《Analytical letters》2012,45(6):1045-1054
Abstract

A derivative spectroscopy technique for the simultaneous determination of plasma amitriptyline and perphenazine is proposed. The described method is fast and requires only one extraction for both drugs.  相似文献   

16.
In our paper the studies on the initial stage of autoxidation of cis- and trans-9-octadecenoic acid methyl esters were reported. The applied analytical methods were: (1) high-resolution NMR spectroscopy; (2) absorption iR spectroscopy; (3) adsorption TLC. The complementary methods were: determination of peroxide number, acid number and iodine number in the course of autoxidation. Our results pointed to the fact that the oxidation of trans-isomer showed the more restrained character. We tried to suggest the influence of structure of the examined compounds and of the peroxides formed in the initial stage of autoxidation on the course of this process.  相似文献   

17.
《Analytical letters》2012,45(13):2499-2513
Abstract

Two simple colorimetric methods for the determination of certain cephalosporins (cefaclor and cefadroxil) and amoxycillin sodium are described. The suggested methods depend upon the oxidation of these compounds using sodium hypochlorite (SHC) and 1-chlorobenzotriazole (1-CBT) in alkaline medium and colorimetric measurment of the chromophore formed. The different experimental parameters are studied and incorporated into the procedures. The mean percentages found range from 100.0 ± 0.4 to 100.5 ± 0.9. The proposed methods have been successfully applied to the analysis of some pharmaceutical formulations and the results obtained have been statistically compared with those obtaind using the official methods. The proposed methods are convenient, rapid within the concentration range 15-123 μg. ml?1.  相似文献   

18.
《Analytical letters》2012,45(11):1405-1417
Abstract

Eosin reacts with phenothiazine derivatives in dichloroethane to give intense fluorescent compounds having their excitation maximum at 318 nm and emission maxima at 450, 460 and 465 nm for prochlorperazine dimaleate, thiethylperazine dihydrochloride and trifluoperazine dihydrochloride, respectively. Under the optimum conditions, samples of 1-10 μg ml?1 could be determined rapidly with coefficient of variation less than 1.8 %. This fluorescence reaction was also applied successfully to the determination of phenothiazine drugs in some pharmaceutical preparations.  相似文献   

19.
《Analytical letters》2012,45(11-12):2485-2500
Abstract

The potential of the continuous addition of reagent (CAR) technique, developed for reactions on the millisecond time scale, in fluorimetric reaction-rate methods, is evaluated. The approach was applied to the classical fast reaction involving the oxidation of thiamine to fluorescent thiochrome effected by potassium ferricyanide in basic solutions. Practical problems associated with this system were readily avoided by using the CAR technique. Several kinetic methods have been developed for the determination of thiamine; all are very sentitive (detection limit, 2. 5x10?9 M) compared to other fluorimetric equilibrium and reaction-rate methods and are suitable for routine analyses (sample throughput, 100 h?1).  相似文献   

20.
《Analytical letters》2012,45(5-6):495-501
Abstract

The determination of fluorescence quantum yields by measurements of fluorescence intensities of unknown and standard fluorophores at maximum possible fluorescence intensity (high absorbance) is simple and offers some distinct advantages over measurements with weakly absorbing solutions of the fluorophores.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号