摘要:

Penicillinase and penicillin amidase were immobilized, with similar yield, by physical entrapment in porous beads of poly-2-hydroxyethyl methacrylate matrix formed by gamma-irradiation. Flow-injection analysis of penicillins was performed by using a column reactor filled with enzyme-loaded polymer beads and a wall-jet pH-metric micro-cell with a combined flat-membrane glass electrode as the sensing element. With both enzymes it was possible to have either a linear response dynamic range or a logarithmic one by appropriate selection of buffer capacity and flow rate of the carrier solution.

ISSN:0003-2719    

DOI:10.1080/00032719508000352

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

A simple, rapid and selective biosensor for reagent-less L-tryptophan determination has been developed. Tryptophan-2-monooxygenase was immobilized on silica gel. A Clark-type membrane O2electrode was used as a physical transducer. A positive correlation between signal and L-tryptophan concentration was observed between 0.025 mM and 1.0 mM L-tryptophan. The sensitivity of the biosensor to L-phenylalanine was 30% and to L-methionine 6% relative to L-tryptophan, while there was no response to L-glycine, L-leucine, L-valine, L-isoleucine L-ornithine, L-alanine, L-proline, L-lysine and L-phenylglycine. The analysis time was 2 minutes, and the biosensor has retained activity for greater than 4 months. The biosensor was successfully used for L-tryptophan determination in the nutrition broth.

ISSN:0003-2719    

DOI:10.1080/00032719508000353

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

A sensitive protein assay method which involves the reaction of TPPS4with protein is described. When protein is added to TPPS4solution, an absorption band with the maximum at 488 nm appears and the absorbance is proportional to the concentration of protein. Just Like the Soret absorption of the porphyrin, the new band is very narrow and there is no overlap at all between them, which means the free dyes would not give any background for the detection of the protein-TPPS4complexes. A new spectrophotometric method for determination of protein has been constructed and applied to the determination of human plasma protein and urinary protein; The assay using microtiter plates has also been studied.

ISSN:0003-2719    

DOI:10.1080/00032719508000354

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The amperometric method using the flow injection system has been developed for the determination of bilirubin. Bilirubin is oxidized to biliverdin at the glassy carbon working electrode. The optimum conditions were investigated. Linear calibration curve was obtained between 1.0×106and 1.0×10−3M, with a sampling rate of 20 samples h−1and a relative standard deviation of 3.2%. The limit of detection is 4.0×10−7M. Interference of hemoglobin was not observed.

ISSN:0003-2719    

DOI:10.1080/00032719508000355

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

A kinetic-spectrophotometric method is developed for the determination of trace amounts of thiocyanate based on its inhibition action on the ferroin-periodate reaction. The method is rapid, simple, sensitive and selective. Thiocyanate in the concentration range of 20–200 ng/ml could be determined by the method. The limit of detection of the method is 16 ng/ml and the relative standard deviation is 2.9% for 10 determinations of 40 ng/ml thiocyanate. The proposed method is applied to the determination of thiocyanate in human blood serum and saliva.

ISSN:0003-2719    

DOI:10.1080/00032719508000356

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

A simple, highly sensitive and selective fluorescence synergistic method has been developed for rapid determination of stilboestrol with Triton × — 100 (λex= 318nm, λem= 415nm) at pH 8.80 ∼ 10.20. The calibration graph is linear over the range of 0.0 ∼ 30.0μg/10ml. The detection limit is 0.03μg/ml stilboestrol. The method has been successfully applied for the determination of stilboestrol in tabellae stilboestrol and injectio stilboestrol with satisfactory results. It can also be applied for the determination of stilboestrol in body fluid of special patients.

ISSN:0003-2719    

DOI:10.1080/00032719508000357

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Two acid dye reagents have been utilized for spectrophotometric determination of triamterene in pure form and in pharmaceutical preparations. The dyes used are bromophenol blue (B. P. B), and bromothymol blue (B. T. S. They form a chloroform-soluble, coloured ion association complex with triamterene, at pH 3.4 and 3.2 using B. P. B and B. T. B, respectively. The formed complex could be extracted and measured spectrophotometrically at 417 nm for both dyes. The molar ratio of the formed drug-dye ion association complex is found to be 1:1 for both dyes used, as deduced by applying Job's method. Linearity was obtained using concentration ranges of 2.5–10 μg, and 2.5–15 μg. ml−1of triamterene with B. P. B. and B. T. B. respectively. The validity of the procedure was assessed by applying the standard addition technique. Results obtained by using the proposed procedure were statistically analysed and compared with those obtained by adopting the pharmacopoeial method.

ISSN:0003-2719    

DOI:10.1080/00032719508000358

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

A simple, rapid and sensitive fluorimetric method is described for the determination of metyrosine in bulk, in dosage forms and in biological fluids. The method is based on measuring the fluorescence produced in isopropanol. The fluorescence is measured at 610 nm after excitation at 282 nm. The fluorescence intensity is a linear function of metyrosine concentration over the range of 0.2–3.2 μg ml−1with a detection limit of 0.08 μg ml−1. The advantages of the proposed method over other methods were discussed.

ISSN:0003-2719    

DOI:10.1080/00032719508000359

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

A simple, rapid and reproducible high-performance liquid chromatographic (HPLC) method for the determination of loracarbef in human plasma has been developed and evaluated. Plasma protein was precipitated with ammonium sulfate. The drug and the internal standard (Cefetamet) were eluted from a μ-bondapak C-18 column with a mobile phase consisting of acetonitrile:methanol:water:glacial acetic acid (2.5:17.5:79.2:0.8%, v/v). The column eluent was monitored at 265 nm. Quantification was achieved by the measurement of the peak-height ratio of the analyte to the internal standard and the limit of quantification for loracarbef in plasma is 0.5 ug/ml. The within-day coefficient of variation (CV) ranged from 2.28% to 3.67%, and between-day CV from 2.38% to 5.59% at three different concentrations. The absolute recoveries ranged from 91.1% to 93.88%, and the relative recoveries from 93.4% to 108% at three different concentrations. Preliminary stability tests showed that loracarbef is stable for at least 5-weeks in human plasma after freezing. The method is applied for the determination of the pharmacokinetic parameters of loracarbef after oral administration to 2 beagle dogs.

ISSN:0003-2719    

DOI:10.1080/00032719508000360

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

A simple and accurate method was described for the quantitative determination of flufenamic acid utilizing precipitation reactions with silver (I), copper (II) and iron (III). Flufenamic acid was precipitated from its neutral alcoholic solution by silver nitrate, copper acetate or ferric chloride standard solutions followed by direct determination of the above cited ions in the precipitate or its indirect determination in the filtrate applying atomic absorption spectroscopy. The optimum conditions for precipitation have been carefully studied. The molar ratio of the reactants were ascertained. Statistical analysis of the results obtained compared to the results of the official method revealed equal precision and accuracy. The suggested procedures were applied for determining flufenamic acid in pharmaceutical preparations as well and proved validity.

ISSN:0003-2719    

DOI:10.1080/00032719508000361

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor