摘要:

During the course of our scientific careers, and after reading numerous original research papers and reviews submitted for publication to various journals or books, it has become apparent to us that many, if not most, academic researchers have little use for method validation studies or demonstrations. Now, that may sound a bit harsh or a strong way to start this mini-review, but this situation has been our collective impression after carefully reading and commenting on hundreds of submitted journal manuscripts over perhaps the past 25 years.

ISSN:0003-2719    

DOI:10.1080/00032719908542878

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

An amperometric immunosensor for fast immunoassay of protein A has been developed. The disposable immunoelectrode consists of highly dispersed carbon modified by immobilized anti-protein A antibodies. The flow-through technique permits high automation of the entire measuring procedure. The detection is based on peroxidase-labeled anti-IgG antibodies captured by the immunoelectrode as a result of immunointeraction. The immunoassay employing a 'sandwich' scheme for the determination of different proteins with a detection limit in the nanomolar range is demonstrated. The immunosensor allows fast determination of protein A with an overall analysis time as low as 22 min. It can be further developed forStaphylococcus aureusassay based on the protein A expressed by this microorganism. The immunoassay system can be arranged as a portable device for fast analyses. The environmental application of the device is associated with on-site monitoring of bacterial contamination under field conditions.

ISSN:0003-2719    

DOI:10.1080/00032719908542879

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

The anodic polarographic behavior of aztreonam was studied in different supporting electrolytes. In 0.1 M hydrochloric acid, a single, well-defined, diffusion-controlled anodic wave was produced. The current-concentration relationship was found to be rectilinear over the ranges 2x10−5to 2x10−3M and 1x10−5to 1.6x10−1M in the direct current (DC) and differential pulse polarography (DPP) modes, respectively, with a minimum detectability of 4x10−6M using the latter technique. The mechanism of the electrode reaction was verified. The proposed method was applied successfully to the determination of aztreonam in pure form, in dosage forms and in biological fluids. L-arginine which is frequently co-formulated with aztreonam did not affect the polarographic signal of aztreonam to any significant extent.

ISSN:0003-2719    

DOI:10.1080/00032719908542880

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

A rapid and sensitive detection method for the determination of 5-fluorouracil(5-FU) in real samples such as human urine and bovine serum albumin (BSA) was described. A carbon fiber microdisk electrode was used to perform end-column amperometric detection in capillary zone electrophoresis. The detection limit was as low as 2.5x10−7M and the wider linear range for the concentration was between 5x10−6and 1x10−4M with a correlation coefficient of 0.995.

ISSN:0003-2719    

DOI:10.1080/00032719908542881

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

A newly sensitive TLC-fluorescence scanning densitometer (TLC-F) is described for the simultaneous determination of tetracycline (TC) and 4-epimeric tetracycline (4-ETC), using a mobile phase system of chloroform: methanol:acetone:1% aqueous ammonia (10:22:53:15, v/v) and a silica gel thin-layer, previously treated with 0.27mol/L sodium EDTA solution adjusted to pH 9.0. The TC and 4-ETC were well separated and their Rfvalues are 0.64 and 0.24, respectively. The excitation wavelength was set at 365nm. The linear ranges are 0.96˜96.2 ng for TC and 0.96˜48.1 ng for 4-ETC. The limit of detection for TC and ETC are 0.31ng and 0.57ng, respectively. The epimeric reaction between TC and 4-ETC was studied. Their recoveries in urine are 97%∼106% and the relative standard deviations (RSDs) of both are less than 4.0%.

ISSN:0003-2719    

DOI:10.1080/00032719908542882

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

The aim of this research was to study and to standardize a high-performance liquid chromatography (HPLC) and absorbance ratio method for the determination of hydrochlorothiazide and lisinopril in commercially available pharmaceutical dosage forms. An HPLC method has been developed for the simultaneous determination of hydrochlorothiazide and lisinopril from formulations, using acetonitrile:water (20:80 v/v) (pH 3.8), as a mobile phase at flow rate of 1.0 mlmin−1and LiChrosorb RP -C18column (5 μ, 20cmx4.6 mm), as a stationary phase. Detection was carried out using a UV detector at 213.0 nm. In the second method, an absorbance ratio method, the determination of hydrochlorothiazide and lisinopril was performed by using the absorbances read at 272.0 nm, 258.8 nm and 262.7 nm in the zero-order spectra of their mixture. The absorbance ratio was also developed as a comparison method.

ISSN:0003-2719    

DOI:10.1080/00032719908542883

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

A potentiometric clenbuterol-selective electrode was developed based on a conducting poly(aniline) (PA) film immobilized on a glassy carbon electrode surface and a poly(vinyl chloride)(PVC) sensing membrane containing an ion pair complex of clenbuterol(CB) with tetraphenylborate. The effects of various conditions for the electropolymerization of PA such as electrochemical method, conducting support, aniline concentration, polymer (PA) film thickness were investigated in relation to the slope and linearity of calibration graphs. The electrode exhibited a Nernstian response in the CB concentration range 1x10−1to 3.9x10−6M with a slope of 60.6mV/decade (25°C). The potentiometric selective coefficients against structurally similar drugs such as epinephrine and salbutamol were of the order of 1x10−3. The electrode was successfully applied to the determination of CB in drug formulations using the calibration curve technique and also in human urine.

ISSN:0003-2719    

DOI:10.1080/00032719908542884

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

A simple bonded phase liquid chromatographic method has been described for rapid, selective and sensitive assay of chlorpheniramine maleate in human serum. The method utilized a 5 μm octadecasilane (C18) Lichrosphere RP column (250 x 4.6 mm i.d.). The mobile phase consisted of acetonitrile-methanol- 0.075 M ammonium dihydrogenphosphate (23: 9: 68%, v/v/v) at pH 2.8. Detections were carried out at 269 nm at ambient temperature. Brompheniramine was employed as an internal standard, running time per single analysis at a flow rate of 1.2 ml/min was no longer than 7 minutes. A mean absolute recovery of about 86% and a minimum detectable concentration of 0.5ng/ml of serum were obtained. The within and between-day coefficients of variation for 2.5-15ng/ml ranged from 5.96 to 8.15% and from 6.81 to 8.79%, respectively. The response of the assay over the same concentration range was linear with a mean correlation coefficient, (r), better than 0.995.

ISSN:0003-2719    

DOI:10.1080/00032719908542885

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

The simplicity and robustness of inverse multiple linear regression (ILS) as a method for the analytical control of pharmaceutical preparations by UV–vis spectrophotometry is demonstrated. This calibration technique establishes a linear relation between the analyte concentration as dependent variable and absorbance values measured at a small number of wavelengths as independent variables. In this work, ILS was used to quantify the active principal in a pharmaceutical preparation commercially available as aqueous solution.

ISSN:0003-2719    

DOI:10.1080/00032719908542886

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

Peroxynitrite-induced oxidative stress was investigated in red blood cells by luminol-dependent chemiluminescence. Red blood cells are susceptible to free radical damage due to the abundance of oxygen, presence of iron and other agents such as polyunsaturated fatty acids. Peroxynitrite (ONOO-), formed by the reaction of superoxide radical with nitric oxide radical, has been shown to cause protein and lipid oxidation. Addition of ONOO- showed a dramatic increase in chemiluminescence, but treatment with glutathione ethyl ester, an antioxidant, partially reduced the increase in chemiluminescence. The results show that red blood cells are a good model to mimic oxidative stress conditions and are discussed with relevance to neurodegenerate disorders.

ISSN:0003-2719    

DOI:10.1080/00032719908542887

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor