Biomedical subjects

Jon Sanz

Publications and source records attributed to Jon Sanz.

3 recordsLinked to original sources

PubMed2006

Current perspectives in analyte extraction strategies for tin and arsenic speciation.

Nowadays, reliable and robust detectors can be considered standard laboratory instrumentation, which, for most of the elements provide quantitation limits in the lower ng/g range. Despite these advances in detector technology, sample preparation is by far the most important error source in modern analytical method development and can be judged as the "Achilles' heel" of any analytical process regarding reliability of the obtained results and time consumption. The aim of the present review is to highlight modern trends for tin and arsenic speciation, as these analytes can be considered as models for challenges in modern method development in this field. First background information, legislative aspects and current needs are elucidated. Then the role of sample treatment within the process of method development in speciation is discussed, followed by a presentation of modern extraction techniques, matching the requirements for arsenic and tin speciation analysis: to provide mild conditions in order to ensure species preservation, to improve species recovery, to enhance sample throughput and to be suitable for hyphenation with chromatographic separation systems. The review includes applications on tin and arsenic speciation, covering the period of 2001-2006.

Analytic Sample Preparation Methods↗

PubMed2005

Recent developments in solid-phase microextraction coatings and related techniques.

During the last decade, solid-phase microextraction (SPME) has gained widespread acceptance for analyte matrix separation and preconcentration. Relatively few data are currently available dealing with in-house production of fibres with tailor-made properties to be used for SPME, though recently the number of publications evaluating new coatings has been considerably growing. This review, centred on publications that appeared during the last five years, is resuming different approaches which can be used for fibre production and further summarises alternative techniques closely related to SPME, such as in-tube extraction or single-drop microextraction (SDME). The aim is to give the reader a concise overview of recent developments in new coating procedures and materials, including the respective applications.

Chemical Fractionation↗

PubMed2004

On-line separation for the speciation of mercury in natural waters by flow injection-cold vapour-atomic absorption spectrometry.

Inorganic mercury and methylmercury are determined in natural waters by injecting the filtered samples onto a low cost commercial flow injection system in which an anion exchange microcolumn is inserted after the injection loop (FIA-IE). If hydrochloric acid is used as the carrier solution, the HgCl4(2-) species (inorganic mercury) will be retained by the anion exchanger while the CH3HgCI species (methylmercury) will flow through the resin with negligible retention. Four anion exchangers and seven elution agents were checked, in a batch mode, to search for the best conditions for optimal separation and elution of both species. Dowex M-41 and L-cysteine were finally selected. Mercury detection was performed by cold vapour-electrothermal atomic adsorption spectrometry (HG-ETAAS). Both systems were coupled to perform the continuous on-line separation/detection of both inorganic mercury and methylmercury species. Separation and detection conditions were optimized by two chemometric approaches: full factorial design and central composite design. A limit of detection of 0.4 microg L(-1) was obtained for both mercury species (RSD < 3.0% for 20 microg L(-1) inorganic and methylmercury solutions). The method was applied to mercury speciation in natural waters of the Nerbioi-lbaizabal estuary (Bilbao, North of Spain) and recoveries of more than 95% were obtained.

Animals↗