Solid phase extraction (SPE) and supercritical fluid extraction (SFE) have become established in the field of analytical chemistry over the last five years. Both techniques are alternatives to classical analytical extraction methods used to separate analytes from solid and liquid matrices. SFE is an alternative to traditional liquid-solid extraction methods, the two most common being soxhlet an...

Phthalate esters are endocrine disrupters or mutagens. They are widely used as plasticizers and can be usually found in environmental samples, such as food, soil and polluted air. However, it is difficult to directly determine phthalate esters owing to their relatively low concentration and complex matrices. Therefore, preconcentration and separation have become increasingly important. In recen...

BACKGROUND High-performance liquid chromatography-tandem mass spectrometric (LC-MS/MS)1 analysis of plasma free metanephrines is the most diagnostically sensitive and specific screening test for the diagnosis of pheochromocytoma. We sought to develop an in-house method for this expensive test METHODS We used off-line isopropanol protein precipitation of plasma to remove interfering substances...

A polymeric microfluidic device for solid-phase extraction (SPE)-based isolation of nucleic acids is demonstrated. The plastic chip can function as a disposable sample preparation system for different biological and diagnostic applications. The chip was fabricated in a cyclic polyolefin by hot-embossing with a master mold. The solid phase consisted of a porous monolithic polymer column impregna...

A simple, semi-automated, microcolumn solid-phase extraction (SPE) system is optimized for the extraction, preconcentration and HPLC analysis of seven different explosives and explosive derivatives contaminating seawater, river water and well water samples. The microcolumns were constructed from 1/16 in. O.D. PTFE tubing (1 in.=2.54 cm) packed with 0.5-1.5 mg of SPE material. LiChrolut EN or Po...

Among the most important Relds in analytical chemistry are medical, food and environmental analysis, where the target analytes are often present at very low concentrations in rather complex matrices. Methods currently used for analysis, such as liquid chromatography, gas chromatography or capillary electrophoresis, must therefore be preceded by a selective isolation and concentration step. Comm...