Determination of adrenolytic drugs by SPME-LC-MS.
ABSTRACT Five adrenolytic drugs have been analyzed by liquid chromatography-mass spectrometry (LC-MS). Samples were prepared by solid-phase microextraction (SPME) using polypyrrole fibers coated on stainless steel support as an adsorbent for the drugs. Adsorption efficiencies were 95% and were close for all the drugs investigated. Relative standard deviations (RSD), calculated for samples prepared in standard solutions, were in the range 2.5-13%, however RSD values for the drugs in human plasma were 2.5-4.5%. Using LC-MS the limit of detection (LOD) and the limit of quantification (LOQ) were in the ranges 0.11-0.18 and 0.39-0.54 ng mL(-1), respectively, for the five drugs.
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ABSTRACT: The human population continues to grow exponentially in the fast developing and most populated countries, whereas in Western Europe it is getting older and older each year. This inevitably raises the demand for better and more efficient medical services without increasing the economic burden in the same proportion. To meet these requirements, improvement of medical diagnosis is certainly a key aspect to consider. Therefore, we need powerful analytical methodologies able to go deeper and further in the characterization of human metabolism and identification of disease biomarkers and endogenous molecules in body fluids and tissues. The ultimate goal is to have a reliable and early medical diagnosis, mitigating the disease complications as much as possible. Microextraction techniques (METs) represent a key step in these analytical methodologies by providing samples in the suitable volumes and purification levels necessary for the characterization of the target analytes. In this aspect, solid-phase microextraction (SPME) and, more recently, microextraction by packed sorbent (MEPS), are powerful sample preparation techniques, characterized by their reduced time of analysis, low solvent consumption, and broad application. Moreover, as miniaturized techniques, they can be easily automatized to have a high-throughput performance in the clinical environment. In this review, we explore some of the most interesting MEPS and SPME applications, focusing on recent trends and applications to medical diagnostic, particularly the in vivo and near real time applications.Analytical and Bioanalytical Chemistry 01/2014; · 3.66 Impact Factor
Article: CHROMATOGRAPHY: RECENT PROGRESS[Show abstract] [Hide abstract]
ABSTRACT: In recent years, substantial research has been devoted to the development of new liquid-liquid microextraction methods for sample preparation. These microextration methods were performed by several techniques such as: liquid-phase microextraction (LPME) or membrane-assisted solvent extraction (MASE), hollow fiber liquid phase microextraction (HF-LPME), single drop-phase microextraction (SDME), liquid-liquid-liquid-microextraction (LLLME), dispersive liquid-liquid microextraction (DLLME), and ionic liquid dispersive liquid-liquid microextraction (IL-DLLM). Performance extraction increasing was achieved by using the ultrasound field; techniques such as: ultrasound-asisted liquid phase microextraction (ULPME), ultrasound-asisted ionic liquid dispersive liquid-phase microextraction (UILDLPM), ultrasound-asisted dispersive liquid-liquid microextraction (UDLLME) and ultrasound-asisted headspace liquid-phase microextraction (UHS-LPME) being used for extraction from complex matrix. Also microwave field was used for solid sample preparation emprouving. Other techniques such as solid phase extraction (SPE), solid phase microextraction (SPME) and stir bar solvent extraction (SBSE) were frecventlly used in liquid sample preparation. The best results are obtained after careful optimization.Journal of Liquid Chromatography & Related Technologies - J LIQ CHROMATOGR RELAT TECHNO. 01/2012;
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ABSTRACT: Multiple headspace solid-phase microextraction (SPME) has proved high efficiency in analysis of volatile compounds in complex samples. Fibers used in multiple headspace SPME must provide a logarithm relationship between peak areas and extraction times. The aim of this work was to investigate the potential of a carbon nanotube doped-polymeric ionic liquid (PILs) fiber for multiple headspace SPME of 2-naphthol in fruit samples, using gas chromatography (GC) for analysis. Based on theory of multiple headspace SPME, β parameters of fruit and aqueous samples were obtained and used for quantitation. The interference effects of sample matrix on proposed multiple headspace SPME method were investigated and compared with that of headspace SPME by determination of significant differences (P) of peak areas. It showed high independence from matrix effects. The proposed multiple headspace SPME-GC method also exhibited high repeatability (relative standard deviation of 2.56%) and recoveries (81.9-110%) for the analysis of real samples.Talanta 06/2014; 123:18–24. · 3.50 Impact Factor