Headspace ionic liquid-based microdrop liquid-phase microextraction followed by microdrop thermal desorption-gas chromatographic analysis. 2010

Jie Zhang, and Hian Kee Lee
Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore.

Headspace microdrop liquid-phase microextraction (LPME) using ionic liquids as extracting solvents, followed by gas chromatography-electron capture detection was successfully developed to determine organochlorine pesticides in soil samples. A feature of the developed procedure is the simple handling of the ionic liquid extract in a normal, unmodified gas chromatograph injection port such that no special provision was needed to ensure that the ionic liquid did not contaminate it. This was achieved by only exposing the ionic liquid extract in the injection port while it was still attached to the syringe needle tip (i.e. mirroring the extraction configuration) to permit volatilization of the analytes, instead of injecting the extract. In this way, the spent ionic liquid could be recovered from the injection port, obviating the need to clean the port. Four 1-butyl-3-methylimidazolium-based ionic liquids were investigated, and 1-butyl-3-methylimidazolium hexafluorophosphate was finally selected as the most suitable extracting solvent. Parameters that affect the extraction and determination of the organochlorine pesticides were studied. Under the optimal conditions, the proposed method produced good linearity over a concentration range of 5-250 ng/g. Limits of detection ranging from 0.25 to 0.5 ng/g were achieved.

UI MeSH Term Description Entries
D007267 Injections Introduction of substances into the body using a needle and syringe. Injectables,Injectable,Injection
D002849 Chromatography, Gas Fractionation of a vaporized sample as a consequence of partition between a mobile gaseous phase and a stationary phase held in a column. Two types are gas-solid chromatography, where the fixed phase is a solid, and gas-liquid, in which the stationary phase is a nonvolatile liquid supported on an inert solid matrix. Chromatography, Gas-Liquid,Gas Chromatography,Chromatographies, Gas,Chromatographies, Gas-Liquid,Chromatography, Gas Liquid,Gas Chromatographies,Gas-Liquid Chromatographies,Gas-Liquid Chromatography
D004583 Electrons Stable elementary particles having the smallest known negative charge, present in all elements; also called negatrons. Positively charged electrons are called positrons. The numbers, energies and arrangement of electrons around atomic nuclei determine the chemical identities of elements. Beams of electrons are called CATHODE RAYS. Fast Electrons,Negatrons,Positrons,Electron,Electron, Fast,Electrons, Fast,Fast Electron,Negatron,Positron
D005591 Chemical Fractionation Separation of a mixture in successive stages, each stage removing from the mixture some proportion of one of the substances, for example by differential solubility in water-solvent mixtures. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed) Fractionation, Chemical,Chemical Fractionations,Fractionations, Chemical
D006843 Hydrocarbons, Chlorinated Hydrocarbon compounds with one or more of the hydrogens replaced by CHLORINE. Chlorinated Hydrocarbon,Chlorinated Hydrocarbons,Organochlorine Compound,Chlorine Compounds, Organic,Organochlorine Compounds,Compound, Organochlorine,Compounds, Organic Chlorine,Compounds, Organochlorine,Hydrocarbon, Chlorinated,Organic Chlorine Compounds
D012987 Soil The unconsolidated mineral or organic matter on the surface of the earth that serves as a natural medium for the growth of land plants. Peat,Humus,Soils
D013594 Syringes Instruments used for injecting or withdrawing fluids. (Stedman, 25th ed) Hypodermic Syringes,Syringe, Karman,Hypodermic Syringe,Karman Syringe,Syringe,Syringe, Hypodermic,Syringes, Hypodermic
D013696 Temperature The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms. Temperatures
D013997 Time Factors Elements of limited time intervals, contributing to particular results or situations. Time Series,Factor, Time,Time Factor
D014867 Water A clear, odorless, tasteless liquid that is essential for most animal and plant life and is an excellent solvent for many substances. The chemical formula is hydrogen oxide (H2O). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed) Hydrogen Oxide

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