摘要:

The biocatalytic activity of laccase fromCoriolus hirsutusin non-aqueous environments is exploited for developing an organic-phase amperometric biosensor. The Eastman-AQ polymeric film, known for its stability in organic media, is used to entrap the enzyme onto the glassy carbon surface. The resulting electrode responds rapidly to low concentrations of catechols and hydroquinone in various alcohols. The detection limit for hydroquinone is 6×10−7M. Various experimental variables, influencing the response of the organic-phase biosensor, are explored. With flow injection, 60 samples per hour can be processed with a relative standard deviation of 1.3%.

ISSN:0003-2719    

DOI:10.1080/00032719308017378

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The long-time stability of enzyme electrodes consisting of immobilized enzyme and an oxygen probe was examined at 30°C and 15∼20°C (the sensitivity was 60% of that found at 30°C). The lactate (based on oxidase fromPediococcussp.) and the alcohol (based on oxidase fromPichia pastoris) electrodes were stable for more than 14 days at 15∼16°C, but for 2∼3 days at 30°C. As to the pyruvate and the hypoxanthine electrodes, the rapid loss of the stability was prevented by reducing the operational temperature from 30°C to 18∼20°C.

ISSN:0003-2719    

DOI:10.1080/00032719308017379

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A novel method for direct determination of hemolysin activity in antiserum by linear–sweep polarography(LSP) was developed in this paper. This method is based on a reduction wave of active hemolysin in phosphate buffer solution. The peak height of hemolysin is linear proportional to its activity in the range of 6×10−6unit/mL to 2×10−3unit/mL. Deactivated hemolysin, other proteins and chemicals present in biological fluids do not interfere in the assay. This method is very rapid, simple, highly specific and sensitive.

ISSN:0003-2719    

DOI:10.1080/00032719308017380

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

In the present study is described an immunoenzymatic assay for a new semi-synthetic immunomodulator consisting of a fraction derived from the strain ATCC 53966 ofCorynebacterium granulosumto which were coupled polyaminoacid chains as a carrier to improve the oral bioavailability of the compound. This assay consists of having the specific antibody reacting with the compound and to determine the amount of antibody that has bound to the compound. For this the bound antibody was first reacted with the corresponding antispecies IgG antibody labelled with an enzyme and then the immobilized labelled antibody was revealed by a colorimetric reaction using a chromogenic substrate. The assay has further been validated by calculating the correlation factor linking the results obtained using the immuno-enzymatic assay to those obtained by determining with the aid of gas chromatography the concentration of muramic acid, a component characteristic of the compound structure.

ISSN:0003-2719    

DOI:10.1080/00032719308017381

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Simple fluorescence methods involving no sample pre-treatment are investigated concerning the direct determination of salicylate in serum, plasma and synovial fluid (total fluorescence) and of salicylic and salicyluric acids in urine (zero-crossing first-derivative synchronous fluorescence).

ISSN:0003-2719    

DOI:10.1080/00032719308017382

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Piroxicam in pharmaceutical preparations (capsules (C), tablets (T), oral drops (OD), suppositories (S) and simulated sample (SS)) was determined by UV direct spectrophotometry (UVS) at 333 nm, by UV difference spectrophotometry (UVDS) at 327 nm, and in C and T, by high performance liquid chromatography (HPLC). For UVS, Beer's law was obeyed in the range 3.0 – 8.5 μg/mL. The coefficient of correlation (CC), absolute precision (AP) and relative precision (RP) were 0.9999, 0.02 and 0.33%, respectively. The coefficient of variation (CV) for C, T, OD, S and SS were 0.48%, 0.35%, 0.32%, 0.48% and 0.19%, respectively. The recovery average (RA) was 100.22%. For UVDS, Beer's law was obeyed in the range 5.0 – 15.0 μg/mL. The CC, AP and RP were respectively 0.9999, 0.05 and 0.47%. The CV for C, T, OD, S and SS were 0.64%, 0.84%, 0.62%, 0.54% and 0.15%, respectively. The RA was 99.02%. In HPLC determination, a LiChrospher® 100 RP- 18 (5 μm) in LiChroCART® 125-4 column at ambient temperature with a mobile phase consisting of methanol: (buffer solution citric acid - dibasic sodium phosphate pH 3.0) (55:45) and UV detection at 254 nm enabled the determination of piroxicam in C and T. The response peak area versus concentraton presented linearity in the range 10.0 – 100.0 μg/mL. The CC, AP and RP were 0.9997, 0.45 and 0.90%, respectively. The CV was 0.51% – 0.82% and the RA, 97.13%.

ISSN:0003-2719    

DOI:10.1080/00032719308017383

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Cellulose tris (3,5-dimethylphenyl carbamate) known as Chiralcel OD chiral stationary phase (CSP) is one of the most commonly used cellulosic CSPs which have been successfully used for separation, enantiomeric purity determination and analysis of several drug racemates including β-adrenoceptor antagonists.

ISSN:0003-2719    

DOI:10.1080/00032719308017384

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Spectrophotometric and spectrofluorometric methods have been described for determination of catecholamines in pharmaceutical formulations. These depend upon measuring the intensity of the orange colour produced on reacting catecholamines with the ethanolic solution of o-phenylenediamine dihydrochloride at 490 nm and at 560, 410 nm emission maxima with 1,2-diaminoanthrancene and 2-aminophenol. The absorbance obeys Beer's law in the concentration range of 0.092 to 2.48 mg of catechol amines spectrophotometrically from 4.5 to 240 μg spectrofluorometrically

ISSN:0003-2719    

DOI:10.1080/00032719308017385

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A sensitive method for the determination of vanadium in coal fly ash by electrothermal atomic absorption spectrometry is described. Vanadium is separated using a monothio β-diketo liquid chelating exchanger (LCEH) in chloroform medium. The conditions of separation of vanadium i.e., pH, solvent, kinetics of extraction and the effects of various ions have been studied. The instrumental conditions, graphite furnace programme have been optimized. The precision and accuracy of the method were investigated. The detection limit was found to be 0.58 ng. The accuracy of the method has been demonstrated using a reference sample and recovery of spiked vanadium to the fly ash sample digests.

ISSN:0003-2719    

DOI:10.1080/00032719308017386

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A simple, sensitive and selective method for the spectrophotometric determination of Pd(II) has been developed. Palladium (II) reacts with 1,10-phenantroline and 4-nitrobenzenediazobenzene (Cadion A) in the presence of the non-ionic surfactant Peregal 0 to form a stable complex. The maximum absorption of the complex is at 490 nm, its apparent molar absorptivity is 8.01 × 104L · mol−1· cm−1. The composition of Pd : Phen : Cadion A is 1 : 1 : 2. Beer's law is obeyed for Pd in the range of 0–20 μg/25 mL, with EDTA and sodium potassium tartrate as masking agents, common ions do not interfere. The method has been used in the determination of palladium in Pd containing catalysts without separation.

ISSN:0003-2719    

DOI:10.1080/00032719308017387

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor