摘要:

A (-)-nicotine-selective polymer was prepared by molecular imprinting technique using methacrylic acid as a functional monomer. Liquid-chromatographic tests, using the polymers as a stationary phase, exhibited that the basicity of the functional group of (-)-nicotine is crucial for rebinding by the molecularly imprinted polymer. Scatchard analysis implied that the binding sites generated within the polymer are heterogeneous in terms of affinity, and the apparent dissociation constant of the highest affinity binding sites was estimated as 3.7 μM.

ISSN:0003-2719    

DOI:10.1080/00032719608002231

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Mini agarose plugs, containing immobilized cells, were lysed and deproteinized in 3–6 h by a non-enzymatic procedure, using 4 M urea and detergents. The performance ofSaccharomyces cerevisiaeminiCHEF DNA pattern was not affected by the treatment. DNA contained in the miniplugs was completely digested by restriction endonucleases in 1–2 h. This procedure saves time in comparison to the 40 h of incubation with urea used in the original procedure. It also saves reagents and permits a rapid DNA digestion without using PMSF.

ISSN:0003-2719    

DOI:10.1080/00032719608002232

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

A rapid and sensitive homogeneous assay method has been developed for the determination of subtilisin. The method employs a protein substrate labelled with two fluorescent dyes with fluorescence energy transfer (FET) characteristics. The doubly-labelled substrate was prepared by chemically coupling bovine serum albumin with lucifer yellow and rhodamine dyes. The fluorescence emission from the lucifer labels was initially quenched due to the FET to the adjacent rhodamine labels. However, upon the addition of subtilisin into the labelled substrate solution, increased fluorescence was observed as the enzyme hydrolyzed the substrate and reduced the FET effect. The rate of increase in fluorescence due to substrate hydrolysis was used to calibrate the subtilisin assay. It was linear over the range 0–150 ng of the enzyme (n=8, r2=0.985). The assay was fast with a time of 30 sec to exceed the limit of detection (LOD) signal for 60 ng of subtilisin in 600 μl. In this volume, the LOD for the enzyme was 4.2 ng (99% confidence).

ISSN:0003-2719    

DOI:10.1080/00032719608002233

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

A highly sensitive and rapid chemiluminescent assay for the determination of the activity of xanthine oxidase (XOD) was developed. The chemiluminescent signal was obtained from the catalyzed oxidation of hypoxanthine, accelerated and amplified using a Fe-EDTA complex and perborate, which acts on luminol. The same luminescent mixture was previously used as detection system for immunoassays. Two different mixtures were used, which differ in their luminol and perborate content, with (CLMrho) or without (CLMb) addition of 0.1 μM rhodamine fluorophor. The response obtained from XOD standard solutions in buffer was linear from 5 to 500 U L−1and from 0.7 to 250 U L−1for CLMrho and CLMb respectively, at 25°C. 5 and 0.7 U L−1were the detection limits at 1 standard deviation level. The intra- and inter-assay relative standard deviations ranged from 6 to 12 % for both CLM. Measurements were made using the high performance, low-light level imaging Berthold luminograph LB-980 which allows simultaneous determination of several samples distributed on a microtiterplate. Various kinds of milk were analyzed for XOD content, which in pasteurized milk depends on the fat content and in the UHT milk disappears owing to the heat treatment.

ISSN:0003-2719    

DOI:10.1080/00032719608002234

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

This article deals with the design of an unsegmented-flow injection manifold for the simultaneous determination of adrenaline and noradrenaline two structurally related compounds with overlapping spectra. An FIA manifold is proposed for the simultaneous determination in which the sample solution is directly injected into a carrier-reagent stream of aqueous NaOH. The selected wavelengths (first derivative) were 394 and 342 nm, for noradrenaline and adrenaline, respectively with an integration time of 0.4 s. The calibration graphs are linear over the range 2.0–30 ppm for both drugs. The method is applied to different synthetic mixtures of both drugs.

ISSN:0003-2719    

DOI:10.1080/00032719608002235

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The application of a rapid competitive enzyme-linked immunosorbent assay (ELISA) for the measurement of testosterone in flow injection (FI) is presented. The ELISA protocol for the determination of testosterone was performed in 60 min compared to the standard protocol time of 150 min. This was achieved by reducing the antibody incubation time. The ELISA was used successfully to determine testosterone levels in clinical samples of both male and female subjects, and were in good agreement compared to a pathology laboratory which employed an immunoradiometric assay (IRMA).

ISSN:0003-2719    

DOI:10.1080/00032719608002236

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Fluorescent characteristics of 2-naphthol were studied in aqueous solution and in micellar solutions of sodium dodecyl sulfate (SDS), hexadecyl-trimethylammonium bromide (HDTB), and Triton X-100. The enhancement of 2-naphthol fluorescence in SDS neutral solutions was used to establish a method for the determination of 2-naphthol. The method was applied in a medicinal shampoo.

ISSN:0003-2719    

DOI:10.1080/00032719608002237

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The third derivative UV-spectrophotometric method, the “zerocrossing” technique, was used for the simultaneous determination of (dimethylamino) ethyl o-chloro, p-dimethylamino(sulphamoxylphenoxy) acetate hydrochloride [I] and its major decomposition product by hydrolysis, (o-chloro, p-dimethylamino(sulphamoxylphenoxy) acetic acid) [II].

ISSN:0003-2719    

DOI:10.1080/00032719608002238

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The purpose of the study was the quantitative determination of fluconazole by IR spectrophotometry which was realized by the application of the KBr disc technique. In this study dehydrocholic acid was used as internal standard.

ISSN:0003-2719    

DOI:10.1080/00032719608002239

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Xylenol orange is proposed as new sensitive reagent for the colorimetric determination of selenium and tellurium. The reagent forms a pink colored radical cation with selenite and tellurite instantaneously at room temperature in slightly acidic medium. The pink species exhibits an absorption maximum at 568 and 569 nm with a molar absorption coefficient of 2.69 × 104and 2.82 × 1041 mol−1cm−1and Sandell sensitivity of 2.94 and 4.52 ng cm−2for selenite and tellurite, respectively. A 10-fold molar excess of the reagent is necessary for the development of the maximum color intensity. Beer's law is obeyed over the concentration range 0.10–5.50 and 0.13–6.38 μg ml−1of selenium and tellurium, respectively with an optimum concentration range of 0.35–5.10 and 0.40–6.00 μg ml−1, respectively using Ringbom method. The effects of acidity, time, temperature, order of addition of reagent, reagent concentration and the tolerance limit of the method towards various cations and anions usually associated with selenium and tellurium are reported. The proposed method is extremely sensitive, reproducible and has been satisfactorily applied to the determination of trace amount of selenium in polluted water, plant material and medicated shampoo.

ISSN:0003-2719    

DOI:10.1080/00032719608002240

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor