Biomedical subjects

Adela R Rodríguez

Publications and source records attributed to Adela R Rodríguez.

3 recordsLinked to original sources

PubMed2003

Comparative study of coulometric and amperometric detection for the determination of macrolides in human urine using high-performance liquid chromatography.

A high-performance liquid chromatography (HPLC) method using chromatographic conditions optimised in a previous work was applied for the separation of three macrolide antibiotics roxithromycin (Rox), oleandomycin (Ole) and rosamicin (Ros) and further determination of two of them, roxithromycin (Rox) and oleandomycin (Ole), in human urine samples. A comparative study of the behaviour of these macrolides under the two types of electrochemical detection (EC) widely coupled with HPLC, that is coulometric (EC-C) and amperometric (EC-A), was carried out by applying the same multiresidue method. From the assays performed using both detectors the comparison was made taking relevant criteria such as detection limits, linearity, recovery and precision values into account. As a result of this comparison, the coulometric detector appears slightly more suitable than the amperometric one for macrolide analysis.

Anti-Bacterial Agents↗

PubMed2002

Recent developments in quantification methods for metallothionein.

The metallothioneins (MT), a family of proteins with relatively low molecular weight (6-7 kDa), are characterised by the intrinsic presence of 20 cysteinyl groups in their structure, which confers unique metal binding properties to the molecule. Since MT are involved in biological roles, quantification of MT remains an important task. To date, a large number of determination methods have been developed. In this paper recent developments, from 1995 to the present, in methodology employed in quantification studies of total MT and MT polymorphism are described. Different fields were taken into consideration, such as (i) separation techniques and hyphenated systems, (ii) electrochemical methods, (iii) immunological methods and (iv) quantification of MT mRNA. The data presented are based on our own and published results. A brief overview of the use of metallothionein as a biomarker is included as a relevant example of the importance of MT quantification. Finally, general problems associated with determination and evaluation of obtained results within the above four topics are mentioned.

Animals↗

PubMedDate not supplied

Optimization and validation of an analytical procedure for the determination of oxidative hair dyes in commercial cosmetic formulations.

A method has been developed and validated for the analysis of commonly used intermediates of oxidative hair dyes in commercial cosmetic formulations, including both liquid and cream forms, in dark and blonde shades. The commercial formulations are submitted to extraction by an organic solvent, and the resulting aqueous phase is analyzed by reverse-phase HPLC with a gradient elution and detection with DAD and/or ESI-MS-MS. A spectra library containing 200-400 nm spectra of the target substances and their HPLC retention times has been recorded for the identification. The quantification of the target substances is also performed after spiking of the commercial formulations, using an external calibration. The recoveries obtained are very good for all selected intermediates. The whole procedure has been found to be highly suitable for the identification and quantification of dye intermediates. Also implemented has been a database containing (a) the retention times, (b) the spectral, MS, and MS/MS characteristics of the intermediates, (c) acidity constant values of some intermediates of interest experimentally determined and compared to the available NIST values, (d) the chromatographic conditions used, (e) the behavior towards extraction of dye intermediates, and (f) matrix compounds.

Calibration↗