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A novel partitioning collection device comprising a glass cartridge packed with poly(dimethylsiloxane)-coated macroporous silica particles was developed for the precise quantification of polycyclic aromatic hydrocarbons in air. The analyte collection and elution performances achieved using different amounts of poly(dimethylsiloxane) coating were quantitatively evaluated. The sample retention power increased with increasing the coating, and more than 250 L of air could be collected without analyte breakthrough at a sampling temperature of 35°C. During the air collection, the moisture in the air was not retained on the particles due to the hydrophobic surface of the sorbent. A complete and rapid elution of the collected analytes from the device was accomplished by the passage of only 10 mL of acetone with ultrasonication for 1 min. The proposed method was successfully applied for the determination of airborne polycyclic aromatic hydrocarbons in tunnel air. [ABSTRACT FROM AUTHOR]

A novel sampling device based on the partition of target analytes to the extraction medium was developed for the determination of sesquiterpenes in air samples. The extraction medium was prepared by the chemical derivatization of a specially prepared macroporous silica, with a specific surface area of 2.0 m2/g. Taking advantage of the sample extraction, which was mainly based on the partition of sesquiterpenes between air and a C18-bonded phase, the extracted analytes were rapidly and quantitatively desorbed just by passing a small amount of desorption solvent for subsequent analysis by gas chromatography with mass spectrometry. Several experimental conditions, such as the sampling volume and temperature, were systematically evaluated. Under optimized conditions, desorption of the extracted analytes was completed within 1 min with a desorption efficiency of more than 99.9%, achieved using 5 mL of acetone for all the evaluated sesquiterpenes. The applicability of the developed device was confirmed by the determination of several sesquiterpenes from coniferous trees. Although further improvements of the device are required for collecting large volumes or high-temperature air samples, the potential of the developed sampling device was confirmed by determining traces of semivolatile organic compounds in air samples. [ABSTRACT FROM AUTHOR]

A novel miniaturized sample extraction capillary was developed to provide a simple and sensitive method for analyzing gaseous formaldehyde (FA) using conventional high-performance liquid chromatography (HPLC). The extraction capillary was prepared by packing silica gel particles in a stainless steel capillary with a 1.6-mm o.d. Before the gaseous samples were collected, the silica gel particles were impregnated with a derivatizing reagent 2,4-dinitrophenylhydrazine (DNPH) by passing a solution of DNPH through the extraction capillary. FA was derivatized to form the corresponding hydrazone during the active sampling of a gaseous sample, and the derivative was sorbed by the silica gel. The capillary was then directly connected to a six-port valve, and desorption from the capillary and injection into the HPLC were achieved simultaneously by passing a solvent through the capillary. The run-to-run and device-to-device variabilities, as relative standard deviations, were both less than 6.9 %. The limit of detection for FA was 2.5 ng/L using a sampling volume of 100 mL, and a sample collection time of 2 min. Acetaldehyde and acetone in a gaseous sample could also be simultaneously extracted and determined using this method. The applicability of the developed method for determining FA in real indoor air samples was confirmed by comparing the results obtained using the proposed method and a conventional sample preparation method. The developed method enables the rapid and simple sample preparation of gaseous FA and gives a good level of sensitivity. [ABSTRACT FROM AUTHOR]

Highlights: [•] Very volatile organic compounds were extracted by a novel extraction needle. [•] Extracted VVOCs were stored in the extraction needle at room temperature for 3 days. [•] The effects of sample moisture on the determination of VVOCs were investigated. [•] The developed extraction needle was applied to the determination of breath VVOCs. [ABSTRACT FROM AUTHOR]

Highlights: [•] A purge-and-trap method was developed using a novel extraction needle. [•] The needle has multi-bed-type sorbent for extraction of VOCs in water sample. [•] The sampling time of the method was approximately 9min. [•] The method was successfully applied for the analysis of real tap water samples. [ABSTRACT FROM AUTHOR]

Abstract: Fiber-packed sample preparation device was applied to the simultaneous derivatization/preconcentration of ethylene oxide (EO) in air samples. The polymer-coated filaments were packed longitudinally into the needle, and hydrogen bromide (HBr) was loaded onto the filaments in the preconditioning process. Simultaneous derivatization with HBr in the needle was made during the sampling process of the gaseous EO, and the corresponding derivatized analyte, 2-bromoethanol, was desorbed by passing a small amount of methanol through the extraction needle in the heated gas chromatograph (GC) injector. The basic extraction/desorption parameters for EO have been evaluated. The limit of detection (LOD), limit of quantification (LOQ) and the relative standard deviation (RSD) of run-to-run repeatability were 1.8ng/L, 5.4ng/L and less than 4%, respectively, with an extraction time of about 10min. Satisfactory storage performance for three days at room temperature was also confirmed. [Copyright &y& Elsevier]

A miniaturized sample preparation technique that uses a fine-fiber-packed needle as the extraction medium is reviewed, especially in relation to its application to the analysis of volatile organic compounds by gas chromatography. When the needle was packed longitudinally with a bundle of fine filaments (12 µm o.d.) which were also surface-coated with polymeric materials, successful sample preconcentration was obtained. Improved sensitivity was also established by introducing simultaneous derivatization reactions into the extraction process in the fiber-packed needle. The storage performance of the needle clearly demonstrated the potential of the technique for typical on-site sampling during environmental analysis. In this short review, the fiber-packed extraction needle developed by the authors is summarized along with applications that use the fiber-packed needle as a miniaturized extraction device. [ABSTRACT FROM AUTHOR]

Abstract: Miniaturized needle extraction device has been developed as a versatile sample preparation device designed for the rapid and simple analysis of smoking-related compounds in smokers’ hair samples and environmental tobacco smoke. Packed with polymeric particle, the resulting particle-packed needle was employed as a miniaturized sample preparation device for the analysis of typical volatile organic compounds in tobacco smoke. Introducing a bundle of polymer-coated filaments as the extraction medium, the needle was further applied as a novel sample preparation device containing simultaneous derivatization/extraction process of volatile aldehydes. Formaldehyde (FA) and acetaldehyde (AA) in smoker''s breath during the smoking were successfully derivatized with two derivatization reagents in the polymer-coated fiber-packed needle device followed by the separation and determination in gas chromatography (GC). Smokers’ hair samples were also packed into the needle, allowing the direct extraction of nicotine from the hair sample in a conventional GC injector. Optimizing the main experimental parameters for each technique, successful determination of several smoking-related compounds with these needle extraction methods has been demonstrated. [Copyright &y& Elsevier]

Abstract: A novel in-needle extraction device has been developed for the preconcentration of gaseous organic compounds prior to the determination in gas chromatography (GC). As the extraction medium, a copolymer of methacrylic acid and ethylene glycol dimethacrylate was synthesized. Based on the results in the preliminary experiments, the desorption conditions such as desorption temperature and time have been optimized along with the evaluation of the extraction efficiency. The storage performance of the needle extraction device was also studied. The results clearly demonstrated the excellent extraction performance for typical organic solvents and also suggested the future possibility such as in the applications for the analysis of working environments. [Copyright &y& Elsevier]

Abstract: We review the approach to miniaturization of sample preparation using a fiber-packed capillary as the medium, especially for on-line coupling of the processes of sample preparation and chromatographic separation. We summarize our novel use of polymeric fiber filaments as the extraction medium for microscale liquid-phase and gas-phase separations that we have developed. [Copyright &y& Elsevier]

• Miniaturized sample preparation with braid-type extraction medium was developed. • The extraction capillary was prepared using the braid with a metal wire inside. • Applying low voltages to the metal wire, a heat-assisted desorption was made. A novel miniaturized sample preparation device with braid-type extraction medium was successfully developed. Introducing a set of bundles of fine synthetic filaments as the materials of the braid-type extraction medium and also the application of an appropriate tension during the braiding process, the outer diameter of the resulting braid has been controlled. Optimization of the tension enables an easy preparation of a group of braids that can be well-compatible to various internal diameters of capillaries to be packed. The extraction conditions were systematically optimized, and the efficient extraction was confirmed under the optimized conditions. All the parameters affects the desorption efficiency were also optimized, where typical extraction efficiency was more than 90% for the extraction of phenanthrene (1.0 μg/mL) in water. The extracted analyte was desorbed sufficiently by employing a sequential pumping process of two organic solvents. During the preparation of the braid, a different type of fibrous materials could be inserted to the opening at the center of the braid. Taking advantage of this feature of the braid, a stainless steel wire was inserted into the center of the braid. By applying low voltages to the stainless steel wire, a heat-assisted desorption of the extracted analyte was also studied. Experimentally complete desorption (higher than 99.0%) was obtained with the voltage application of 2 V. The lowest limit of quantification (LOQ) and the lowest limit of detection (LOD) for phenanthrene were 0.048 and 0.014 μg/mL, respectively. [ABSTRACT FROM AUTHOR]