摘要:

A glucose sensor based on glucose oxidase and a new mediator - 4,5-dimethyl-4′-methylthio-Δ 2,2′-bi-1,3-dithiole (MTTTF) is described. The background for sensor action is the effective MTTTF cation interaction (apparent bimolecular constant (2.0+/-0.5)*106M−1s−1at 25°C and pH 7.0) with reduced glucose oxidase and the high electrochemical rate of mediator transformation.

ISSN:0003-2719    

DOI:10.1080/00032719308017971

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A heterogeneous on-line fluorescence immunoassay has been developed for a model analyte (transferrin) using a flow injection analysis system containing a controlled pore glass protein A immunoreactor. Lucifer yellow VS (LYVS) a 4-aminonaphthalimide with a large stokes shift and pH independence was the fluorophore. For each assay the antibody-protein A reaction takes place at near neutral pH, and the complexes are eluted at acid pH. Transferrin levels in human serum has been determined by this method, and good within assay variations have been achieved.

ISSN:0003-2719    

DOI:10.1080/00032719308017972

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A potentiometric sensor for perchlorate anion was developed by mixing a silica gel, chemically modified with 1,4-diazabicyclo (2.2.2) octane, with an epoxy polymer and carbon. The electode showed Nernstian response to the perchlorate ion in the concentration range of 10−1and 10−4mol L−1.

ISSN:0003-2719    

DOI:10.1080/00032719308017973

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The electrochemical behaviour of vitamin D3and 25-hydroxyvitamin D3(25-OH D3) in a high performance liquid chromatography system using amperometric detection is described. Separation is carried out using a C18 reversed-phase column and the optimum mobile phase was a 0.1 M LiClO4solution in methanol-water (97:3, v/v) at a flow rate of 1.25 ml/min. 25-OH D3and vitamin D3were eluted with good resolution at retention times of 3 and 6 minutes respectively, and determined by amperometric detection with a glassy carbon electrode at + 1.050 V (vs Ag/AgCl). Calibration graphs for both substances showed good linearity when amounts of vitamin D3between 18 and 312 ng and 27 and 412 ng of 25-OH D3were injected. Detection limits of 8 ng (vitamin D3) and 25 ng (25-OH D3); relative standard deviations of 3.2% (vitamin D3) and 5.8% (25-OH D3) were obtained.

ISSN:0003-2719    

DOI:10.1080/00032719308017974

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

This paper describes a method for the quantitative determination of aluminium in haemodialysis concentrates, based on the adsorption on a static mercury drop electrode of the Al-1,2 dihydroxyantraquinone-3-sulphonic acid complex. The signal was notably increased in presence of calcium. The electrolysis was carried out at -0.900 V. After 60 sec the aluminium contents were measured by differential pulse voltammetry. In these conditions aluminium can be determined in the range 0.65–38 ng/ml with a detection limit (3[sgrave]) of 0.20 ng/ml. The relative standard deviation was in all instances less than 2.1%.

ISSN:0003-2719    

DOI:10.1080/00032719308017975

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Polyspecific antiserum against total rat serum proteins was used to develop specific and sensitive radioimmunoassays for fetuin and bikunin, two minor protein components of rat plasma. The radioimmunoassays proved to be highly useful to trace bikunin and fetuin in the course of developing isolation procedures, since neither specific functional assays nor monospecific antisera were available. The two examples demonstrate that, in general, it will be possible to develop a specific and sensitive radioimmunoassay with antiserum raised against a crude antigen preparation, such as a body fluid or a tissue extract, provided that a minute amount of pure antigen is available for preparing the radioiodinated antigen.

ISSN:0003-2719    

DOI:10.1080/00032719308017976

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A simple and rapid spectrophotometric method for the assay of amodiaquine hydrochloride, chloroquine phosphate and primaquine phosphate is described. The method is based on the interaction of the drug with 7, 7, 8, 8-tetracyanoquinodimethane (TCNQ) as a π-electron acceptor, forming a highly coloured stable radical anion. The molecular ratios of the reactants in the complexes as well as the experimental conditions leading to maximum charge-transfer bands have been studied. Beer's Law is obeyed over aminoquinoline antimalarials concentration range of 0.4–4.0 ug.ml−1. The proposed procedure has been applied successfully to the analysis of antimalarials in their dosage forms and the results are in agreement with those of official methods.

ISSN:0003-2719    

DOI:10.1080/00032719308017977

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A very simple, automatic, fast method for the photometric determination of bromhexine hydrochloride based on the application of kinetic methodology and the stopped-flow mixing technique to the coupling reaction between the diazotized bromhexine derivative and N-(1-naphthyl)ethylenediamine is proposed. The high initial rate of this reaction allows analytical measurements to be made within only 0.5–1 s, which makes the method applicable to automatic routine analyses. The calibration graph is linear over the range 1.5–65.0 μg mL−1and the precision (as %RSD) is less than 2%. The presence of antibiotics such as penicillins and cephalosporins in a 100-fold excess has no effect on the analyte determination. The proposed method was satisfactorily used for direct analysis of pharmaceutical formulations containing these antibiotics.

ISSN:0003-2719    

DOI:10.1080/00032719308017978

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The hydrolytic degradation of antibiotics is very often used as a preliminary step in the analytical procedures for their determination. Therefore, a procedure was developed for measuring small amounts of cefadroxil and cefotaxime in pure samples as well as in formulations.

ISSN:0003-2719    

DOI:10.1080/00032719308017979

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

In order to determine amphetamine and metamphetamine, we have used a method never used before in the legal practice. The aim of our work was to optimize the measurement conditions for the rapid and accurate determination of amphetamine and metamphetamine. We have developed a method which makes possible the unambiguous identification of the hydrochlorides of the hallucinogens amphetamine and metamphetamine, even when these two are present simultaneously. In our work we have used the ammonium salt technique. The information available from the mass spectra (molecular ion, appearance of characteristic fragments) are dependent on the temperature of the direct sample and the ionisation energy. As a consequence, we have primarily studied the influence of the above two parameters upon the mass spectra.

ISSN:0003-2719    

DOI:10.1080/00032719308017980

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor