摘要:

We have developed a reusable piezoelectric immunosensor for human granulocytes. Three different methods for immobilization of the anti-CD 18 antibody on the gold electrode of the immunosensor were tested. The methods showed some differences in terms of stability and sensitivity. Applying an anti-CD 18 antibody layer onto a 10-MHz AT-cut crystal resulted for 2 × 103to 3 × 105cells on the surface in a linear frequency change. The modified crystal was stable for eight weeks when stored desiccated at room temperature.

ISSN:0003-2719    

DOI:10.1080/00032719308017472

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A novel non-flow approach for high-speed optical assays of microliter sample volumes is described. The method is based on the passage of well-defined sample zones, emerging from a computerized pipette, through a radiation path. Sharp absorbance transient peaks accrue from the reproducible travel pattern of the intact samples. Measurements are performed within a modified sample compartment of a conventional spectrophotometer. Repetitive optical measurements at very high rates of 360–1800 samples per hour yield relative standard deviations of 0.3–0.7% with no observable carry over. Such performance characteristics, coupled with the simplicity and low cost, hold a great promise for routine automated assays.

ISSN:0003-2719    

DOI:10.1080/00032719308017473

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A simple and rapid (extractionless) high-performance liquid chromatographic method with ultraviolet detection, at 278 nm, is described for the determination of naproxen in human plasma and urine. Niflumic acid is used as internal standard. The chromatographic system consists of a reversed-phase C18-Spherisorb column with acetonitrile/0.1 M sodium acetate (35:65 v/v, pH 6.14) as the mobile phase. The retention time is 3.0 min for naproxen and 3.8 min for niflumic acid. The total run time is 5 min and the typical assay time is 10 min. The method is sufficiently sensitive for biopharmaceutical studies, after the oral administration of a single sustained release dose.

ISSN:0003-2719    

DOI:10.1080/00032719308017474

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The paper presents for the first time in literature the use of color measurement in leaf diagnosis. It uses the data obtained in certain well- established conditions, in CIE 1976 system for quantifying the color changes of leaves in different sufference (plant or leaf damage) symptoms.

ISSN:0003-2719    

DOI:10.1080/00032719308017475

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A method is described to determine Diethylestilbestrol, Hexestrol and Dienestrol residues in bovine urine, using GC-MSD, working with the SIM system. The urine was centrifuged and the pH adjusted to 9 with 32% NaOH, then subjected to a solid phase extraction procedure using C-18 columns (Baker, spe-500). These columns were eluted with methanol, the alcohol extract was evaporated to obtain a solid residue. The derivation of the stilbene was performed with BSTFA:TMCS 99:1, incubated 15 min at 70°C. The final extracts were dissolved in acetonitrile and injected in a GC-MSD apparatus (quadrupol electronic impact). Three characteristic ions were monitored for each product studied. The detection limit achieved is 2 ppb for Diethylestilbestrol and Hexestrol and 3 ppb for Dienestrol.

ISSN:0003-2719    

DOI:10.1080/00032719308017476

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The frequency shift of a piezoelectric crystal sensor showed a linear dependence on the concentration for drugs which can be hydrolyzed in base aqueous solutions, at a given reacting time after the addition of the base, when the base concentration is basically constant during the entire measurement period. The sensitivity of the analysis method was improved, if crystal responses at different reacting times were recorded and utilized to estimate component concentration, when used for determining atropine sulfate in a pharmaceutical compound. The analytical results indicated that the selective and sensitive analytical procedure could be easily applied in true low concentration pharmaceutical analysis.

ISSN:0003-2719    

DOI:10.1080/00032719308017477

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A spectrophotometric method for the determination of some pharmaceutical amides, hydrazides and thiols is described. The method is based on the reaction of the studied drugs with 2,2-diphenyl-1-picryl hydrazyl (DPPH). The latter is employed to abstract a hydrogen atom from the drugs thereby promoting a process of radical coupling. This results in a reduction of the violet colour of DPPH with the formation of the yellow coloured 2,2-diphenyl-1-picrylhydrazine (DPPH2). This fading in colour of DPPH reagent depends on the concentration of the drug being determined. Beer's law is obeyed in the ranges of 1–5 μg/ml (for isocarboxazid and gliclazide), 0.25–2.5 μg/ml (for isoniazid), 0.5–5 μg/ml (for iproniazid), 1–7 μg/ml (for tolazamide), 2–15 μg/ml (for captopril) and 1–6 μg/ml (for sulphathiourea). The validity of the method was tested by analysing the studied drugs in pure form as well as in tablets. Results of analyses were compared statistically with the official or reported methods.

ISSN:0003-2719    

DOI:10.1080/00032719308017478

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A spectrophotometric procedure for the determination of ampicillin (Amp.) in pure solutions and in its pharmaceutical preparations has been developed. This new method offers advantages of simplicity, rapidity and stability in comparison with the official BP (1980) method. The proposed method is based on the formation of a colour condensation product through the reaction of ampicillin and nitrobenzene derivatives in an alkaline aqueous-acetone medium 40% (v/v). Beer's law is obeyed in the range 0.5–28 μg ml−1. The colours were produced within 20 min. after heating at 60±5°C and stable for at least 6 h. The method is relatively accurate (recovery 100±2%) and precise (RSD 1.9%) and can be used successfully for the preparation of capsules, syrup and ampoules.

ISSN:0003-2719    

DOI:10.1080/00032719308017479

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A method for the spectrofluorimetric determination of nafcillin is proposed (λex= 226 nm, λem= 366 nm), for concentrations between 0.10 and 1.0 μg mL−1. The method was performed in ethanol/water medium (30% V/V), at apparent pH 6.0 provided by adding of phosphate buffer solution with pH = 6.20.

ISSN:0003-2719    

DOI:10.1080/00032719308017480

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A simple spectrophotometric method is developed for the quantitative determination of dequalinium chloride. The proposed method is based on the formation of a green coloured product due to interaction with 7,7′,8,8′-tetracyanoquinodi-methane (TCNQ) in alkaline medium. At the maximum absorption of 488 nm, Beer's law is adhered to over the 2–20 μg ml−1range. Results of analysis of dequalinium chloride by the proposed method agree well with those reported in B.P 1988. The method is simple and rapid since the product is measured directly in solution without extraction.

ISSN:0003-2719    

DOI:10.1080/00032719308017481

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor