摘要:

A micellar electrokinetic capillary chromatographic (MEKC) method is described for the simultaneous determination of zinc protoporphyrin (ZnPP) and protoporphyrin (PP) in whole blood. Reproducibility of migration times and peak areas of ZnPP and PP have been shown to improve significantly with the use of an internal standard.

ISSN:1082-6076    

DOI:10.1080/10826079608006285

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

A method was developed for determination of salicylic acid in anti-acne pharmaceutical preparations involving separation on a preadsorbent high performance thin layer chromatography (HPTLC) silica gel plate with fluorescent phosphor, detection by fluorescence quenching, and quantification by densitometric scanning. Salicylic acid was directly detected and quantified on the plate at levels as low as 1 μg, and no interference was encountered from other ingredients in the medication formulations.

ISSN:1082-6076    

DOI:10.1080/10826079608006286

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Morphine and its sixteen semisynthetic derivatives of pharmacological interest were subjected to planar chromatography. Adequate stationary and mobile phases for both elution and displacement chromatography were found. All these components can be separated by elution mode of development. At the same time, several morphine derivatives can be the member of displacement train. Experiments and results using either straight-phase or reverse phase chromatography with both elution and displacement types of developments are detailed.

ISSN:1082-6076    

DOI:10.1080/10826079608006287

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The experimental design methodology has allowed to optimize the chromatographic separation of polar pesticide molecules (carbofuran, hydroxycarbofuran and aldicarb) by HPLC, owing to the determination of mathematical equations. Second degree equations have been elaborated, dependent upon injected volume, eluent flow and eluent composition. These equations have allowed us to plot Isoresponse Curves which are used to easily visualize and optimize separations. Interactions between eluent flow and polarity are emphasized.

ISSN:1082-6076    

DOI:10.1080/10826079608006288

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

A method based on high performance capillary electrophoresis (HPCE) has been developed for identification and quantitative determination of inhibitors from leguminous seeds. The method allows specific characterization of Kunitz soybean trypsin inhibitor (KSTI) and Bowman Birk inhibitor (BBI) from soybean (Glycine max., L.). Standard curves for the inhibitors showed a satisfactory linearity between normalized peak area and sample concentration, and a good repeatability of the method was found. Identification of protein peaks as proteinase inhibitors was based on their binding to trypsin. The system also proved useful for determination of the number and specificity of inhibitor sites on the individual inhibitors and for binding studies with monoclonal antibodies against the inhibitors.

ISSN:1082-6076    

DOI:10.1080/10826079608006289

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The aim of the present work was to evaluate the feasibility of supercritical fluid extraction (SFE) of some growth-promoting anabolic steroids directly from bovine tissue samples with carbon dioxide as a supercritical fluid. The study was divided into two phases. The first phase involved the optimization of SFE parameters versus recovery and repeatability. Results were obtained by high performance liquid chromatography (HPLC) or supercritical fluid chromatography (SFC). The second set of studies consisted of SFE from the real samples monitored by the combination of high performance liquid chromatography atmospheric pressure chemical ionization mass spectrometry (HPLC/APCIMS). The limit of detection was about 10 ppb, but 100 ppb is the practical detection limit for SFE-HPLC/MS analysis under the experimental conditions used in this study. The results from this work suggested that SFE may be useful for isolation of target compounds from complex biological samples.

ISSN:1082-6076    

DOI:10.1080/10826079608006290

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

An automated solid phase extraction-based procedure for the determination of ketorolac in human plasma was developed and validated. Solid phase extraction of ketorolac tromethamine and ketoprofen (internal standard) was performed on disposable C-18 cartridges directly from plasma samples spiked with the corresponding standards after dilution with saline. All operations were performed automatically by means of a switching-valve assembly in the sample preparation module (Prospekt system), and sample analysis were carried out by on line connection with the HPLC system. Linearity of the analytical methodology was assessed at the concentration range 25–2500 ng/mL ketorolac tromethamine. However, accurate and precise determinations at 5 and 10 ng/mL were obtained by the use of weighing in calibration curve fitting. The mean absolute recoveries for ketorolac tromethamine and the internal standard were 87.7% and 72.9% respectively. Respective intra- and inter-assay precision values were below 7.2 and 18.0%, the later at the 5 ng/mL concentration level of ketorolac tromethamine which was considered as the lower limit of quantitation (3.4 ng/mL in terms of free acid form). Intra- and inter-assay accuracy, expressed as relative error in percentage, were less than 9.5 and 8.8% respectively. The minimal sample handling and the obtained precision and accuracy at the wide range of concentration levels tested make this method suitable for routine quantitations of ketorolac in human plasma.

ISSN:1082-6076    

DOI:10.1080/10826079608006291

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The effect of temperature on efficiency in micellar liquid chromatography (MLC) has been investigated using an SDS micellar mobile phase and a C18stationary phase. Application of the Knox equation to plate count data yielded crucial information about band broadening in MLC. The improvement in chromatographic efficiency with temperature is due to a decrease in both the A (flow anisotropy) and C (stationary phase mass transfer) terms of the Knox equation. The decrease in the A term can be attributed to a shift in the position of the equilibrium of the solute away from the micelle and towards the bulk solvent; the decrease in the C term with temperature can be explained in terms of surfactant adsorption which tends to increase both the thickness and viscosity of the stationary phase. By increasing the operating temperature of the column, less surfactant is adsorbed on the stationary phase.

ISSN:1082-6076    

DOI:10.1080/10826079608006292

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

A sensitive, reproducible and accurate high performance liquid chromatographic (HPLC) method for the quantitative determination of haloperidol in plasma has been developed and validated. Sample preparation involves extraction of haloperidol and diazepam (internal standard) from 0.5 mL plasma. The separation was carried out in a stainless steel, resolve C18column with a mobile phase composed of a mixture of 55% methanol and 45% HPLC water containing 0.2 M ammonium acetate and adjusted to an apparent pH 7.2. The mobile phase was pumped at a flow rate of 1.5 mL/min. The column oven temperature was adjusted at 38°C and the effluent was monitored at 249 nm. The retention times for the internal standard and haloperidol were found to be 5.1 and 6.3 minutes, respectively. Peak-height ratios of the drug to the internal standard were used for the quantification of haloperidol in the plasma samples. The average (±SD) absolute and relative recovery of haloperidol were 97±3.6% and 100 6±1.52%, respectively. The intraday coefficients of variation (CVs) ranged from 1.74 to 4.68%, while the interday CVs varied from 2.31 to 5.23%. The detection limit for haloperidol in plasma was found to be 5 ng/mL.

ISSN:1082-6076    

DOI:10.1080/10826079608006293

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Two HPLC techniques for the determination of raffinose family oligosaccharides (RFO - raffinose, stachyose and verbascose) in pea are described. A reverse phase HPLC (RP-HPLC) on Silica C18column using demineralized water as mobile phase enabled determination of the total content of RFO within less than 10 minutes. Ion Moderated Partition HPLC (IMP-HPLC) using a strong cation exchanger, in calcium form, with demineralized water as mobile phase allowed the determination of all the individual saccharides within 25 minutes. In both RP-HPLC and IMP-HPLC refractometric detection was used. The methods were compared on a representative pea sample series, and in both techniques the lowest detectable concentration in sample solution was calculated to be 5 mg saccharide/mL, i.e., the smallest detectable amount of each saccharide was 100 ng.

ISSN:1082-6076    

DOI:10.1080/10826079608006294

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor