摘要:

A simple and rapid high-performance liquid chromatographic (HPLC) method for the determination of amiodarone (AD) in plasma and tissues was developed. The method involved deproteinization of plasma or homogenized tissue with acetonitrile containing an internal standard (N-Cetylpyridinium chloride) followed by reversed phase chromatography using μ bondapack C18column (10μm) with a mobile phase consisting of acetonitrile - methanol - sodium dihydrogen phosphate buffer (70:10:20%, v/v), the pH adjusted to 4.0 and pumped at flow rate of 1.0 ml/min. The column effluent was monitored at 242 nm. A linear relationship was obtained between peak height ratios (drug to internal standard) versus drug levels over the concentration range of 50–750 ng/ml. The detection limit of AD in plasma and tissues by this method was 20 ng/ml.

ISSN:0003-2719    

DOI:10.1080/00032719508000380

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

A procedure for the analysis of the acid-base characteristics of humic substances based on a self-modeling analysis of synchronous fluorescence spectra, collected at varying pH, and on a non-linear least squares adjustment of potentiometic pH data, is described. The data analysis methodology consists of two steps: first, the number of acid-base systems and the corresponding spectra and distribution diagrams are calculated by evolving factor analysis (EFA) with concentration constraints of the spectroscopic data; second, the potentiometric data is analyzed by a standard non-linear least square procedure using as fixed parameters the number of components and their pKas, determined in the first step of the analysis. As an example, for a sample of marine fulvic acids studied at pH between 2 and 11, four acid-base systems were found with average pKas: 3.1, 4.8, 8.0 and 10.0. The concentrations of the corresponding systems were: 2.55(5), 1.95(7), 0.14(4) and 1.8(3) meq/g.

ISSN:0003-2719    

DOI:10.1080/00032719508000381

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Room temperature phosphorescence characteristics on filter paper of dibenzofuran (DF) and several polychlorinated dibenzofurans (PCDFs) in the presence of different heavy atoms in conjunction with a surface active agent, sodium lauryl sulfate (NaLS), have been studied. The use of this surfactant produces an enhancement of the phosphorescence intensity in all the cases studied, which improve the sensitivity in the determination of DF and PCDFs. The optimization of experimental conditions like type of filter paper, drying and cooling times of the filter paper after spotting the sample, irradiation time, concentration of heavy atom and concentration of surfactant has been carried out. Phosphorescence lifetimes, linear dynamic range, relative standard deviation and limit of detection of the different compounds were also determined.

ISSN:0003-2719    

DOI:10.1080/00032719508000382

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

ISSN:0003-2719    

DOI:10.1080/00032719508000383

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

ISSN:0003-2719    

DOI:10.1080/00032719508000386

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor