Determination of 2,4,6-tricholoroanisole in water and wine samples by ionic liquid-based single-drop microextraction and ion mobility spectrometry.

This article presents for the first time the joint use of ionic liquid-based single drop microextraction (IL-SDME) and ion mobility spectrometry (IMS) for the determination of 2,4,6-trichloroanisol (2,4,6-TCA) in water and wine samples. An imidazolium-based IL was used as extractant taking into account both, its affinity for the analyte and its negligible response in the detector. Water samples were directly analyzed by IL-SDME while wines required a previous solid phase extraction step to remove the interference of ethanol in the ion mobility spectra.

Analytical connotations of point-of-care testing.

The main objective of this Tutorial Review is to approach the modern principles and practices of Analytical Chemistry to Point-of-Care Testing (POCT) systems in order to contribute to improve both the development of new devices and the reliable application of the existing ones. In this article, after contextualization of the topic, POCT systems (POCTs) are fully defined using several approaches. The requirements of a POCT system to be a robust and reliable tool available to patients and medical workers are described as well as their desirable complementary characteristics.

Determination of parabens in cosmetic products using multi-walled carbon nanotubes as solid phase extraction sorbent and corona-charged aerosol detection system.

The potential of carbon nanotubes for the solid phase extraction of parabens in cosmetic products and the detection using a corona-charged aerosol detector (C-CAD) is presented in this work. The analytical procedure is based on a conventional solid phase extraction step for which 20mg of multi-walled carbon nanotubes were packed in a 3-mL commercial SPE cartridge. Methylparaben, ethylparaben, propylparaben and butylparaben were thus isolated and preconcentrated from the pre-treated samples and subsequently separated on a RP-C18 column using acetonitrile:water, 50:50 (v/v) as mobile phase.

Ionic liquid-based single drop microextraction and room-temperature gas chromatography for on-site ion mobility spectrometric analysis.

The combination of ionic liquid-based headspace single drop microextraction (IL-HS-SDME) and room-temperature gas chromatography/ion mobility spectrometry (RTGC-IMS) is presented for the first time using the direct determination of trihalomethanes in waters as model analytical problem. The ionic liquid allows the transference of the analytes from the sample to the analytical system, at the same time that it provides an increase of the sensitivity and selectivity of the determination. An injection unit has been designed to permit the efficient volatilization of the analytes at room temperature and to avoid the entering of IL in the system.

Determination of trihalomethanes in waters by ionic liquid-based single drop microextraction/gas chromatographic/mass spectrometry.

A simple, rapid, solventless method for the determination of trihalomethanes (THMs) (chloroform, bromodichloromethane, dibromochloromethane and bromoform) in water samples is presented. The analytes are extracted from the headspace of the aqueous matrix into a 2 microL drop of the ionic liquid 1-octyl-3-methyl-imidazolium hexafluorophosphate working at 30 degrees C for 30 min. The separation and detection of the target compounds is accomplished by gas chromatography/mass spectrometry owing to the use of an interface that efficiently transfers the analytes extracted in the ionic liquid drop to the gas chromatograph while preventing the ionic liquid from entering the column.

Ionic liquid-based single-drop microextraction/gas chromatographic/mass spectrometric determination of benzene, toluene, ethylbenzene and xylene isomers in waters.

The direct coupling between ionic liquid-based single-drop microextraction and gas chromatography/mass spectrometry is proposed for the rapid and simple determination of benzene, toluene, ethylbenzene and xylenes isomers (BTEX) in water samples. The extraction procedure exploits not only the high affinity of the selected ionic liquid (1-methyl-3-octyl-imidazolium hexaflourophosphate) to these aromatic compounds but also its special properties like viscosity, low vapour pressure and immiscibility with water. All the variables involved in the extraction process have been studied in depth.

Direct coupling of ionic liquid based single-drop microextraction and GC/MS.

The use of ionic liquids as extracting media in single-drop liquid-phase microextraction (SDME) and its direct coupling to gas chromatography/mass spectrometry (GC/MS) is presented. For this purpose, a new removable interface that enables the introduction of the extracted analytes into the GC system, while preventing the ionic liquid from entering the column, has been developed. The determination of three representative pollutants in water samples has been used as a model analytical problem in order to demonstrate the feasibility of the proposed interface.

Continuous flow configuration for total hydrocarbons index determination in soils by evaporative light scattering detection.

A continuous flow configuration is proposed for the estimation of the hydrocarbon index in soils using for the first time evaporative light scattering detection (ELSD). The method is based on a membrane-enrichment of the hydrocarbons of interest (C10-C40), which are previously extracted from the soil matrix with a water:hexane mixture using a household microwave oven. The organic supernatant is cleaned-up through silica, evaporated and redissolved in a sodium dodecyl sulphate aqueous solution which is introduced in the loop of an injection valve.

Continuous autoanalyzer for the evaluation of the exhaustion of industrial degreasing baths based on the determination of total grease and surfactant contents.

A continuous flow autoanalyzer for at-line monitoring of total grease and surfactant contents in alkaline degreasing baths is proposed. For this purpose, a simple, robust, automated configuration has been on-line coupled to an universal response detector, such as the evaporative light scattering one. The proposed autoanalyzer constitutes an advantageous alternative to manual procedures and achieves the determination of both indices in ca.