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• A new analytical method for soil VOCs using a needle extraction device was developed. • The analytes including low molecular weight VOCs like dichloromethane. • Greater recovery and sensitivity were obtained than the standard method. A rapid and quantitative analytical method for volatile chlorinated hydrocarbons and benzene, such as chloroethylene, dichloromethane, and carbon tetrachloride, in soil samples was developed using a needle-type extraction device packed with activated carbon-based adsorbents. The soil sample of 10 g was placed in a glass cartridge and fixed with quartz wool to make sure not to move during the extraction process. After the internal standard solution was spiked into the soil sample, the cartridge was sealed with a polytetrafluoroethylene adapter, and the needle extraction device was used to collect the headspace gas. Analytes were purged from the soil sample and collected on the adsorbent, while pure nitrogen gas was introduced to the soil sample during the sample collection. The sampling time was approximately 10 min for 100 mL of gas sampling. After the sampling process, the extraction needle was directly inserted into a heated injection port of gas chromatography equipped with flame ionization detector (GC-FID) or that hyphenated to mass spectrometry (GC–MS). The extracted VOCs were thermally desorbed and simultaneously introduced to a GC capillary column for subsequent separation and determination. The limit of detection and limit of quantification of all the examined analytes was less than 20 and 60 ng/10 g soil in GC-FID and less than 2.5 and 7.5 ng/10 g soil in the case of GC–MS. Linear calibration curves were obtained up to 10 μg/10 g soil for all the analytes. The relative standard deviations of the ratio of analyte peak area and internal standard peak area were less than 10%. The recovery and sensitivity of analytes confirmed in the proposed method were compared with that obtained with a standard method conventionally employed. [ABSTRACT FROM AUTHOR]

Very volatile organic compounds (VVOCs), such as methanol, acetaldehyde, ethanol, acetone, acetonitrile, and dichloromethane, were extracted from water samples using a needle-type extraction device based on purge and trap analysis. The extracted analytes could then be determined by gas chromatography–mass spectrometry. By introducing carbon molecular sieves as the extraction medium, aqueous VVOCs could be successfully extracted using the extraction needle. The limit of quantification for methanol, acetaldehyde, ethanol, acetone, acetonitrile, and dichloromethane were 75, 75, 7.5, 0.5, 10 and 0.5 μg/L, respectively. This newly developed method was also successfully applied to the determination of VVOCs in commercial samples, such as fruit juice. [ABSTRACT FROM AUTHOR]

Abstract: Background: Isoprene in human breath is said to be related to cholesterol metabolism, and the possibility of the correlations with some clinical parameters has been studied. However, at this stage, no clear benefit of breath isoprene has been reported for clinical diagnosis. In this work, isoprene and acetone concentrations were measured in the breath of healthy and obese subjects using a needle-type extraction device for subsequent analysis in gas chromatography–mass spectrometry (GC-MS) to investigate the possibility of these compounds as an indicator of possible diseases. Methods: After measuring intraday and interday variations of isoprene and acetone concentrations in breath samples of healthy subjects, their concentrations were also determined in 80 healthy and 17 obese subjects. In addition, correlation between these breath concentrations and the blood tests result was studied for these healthy and obese subjects. Results: The results indicated successful determination of breath isoprene and acetone in this work, however, no clear correlation was observed between these measured values and the blood test results. Conclusions: Breath isoprene concentration may not be a useful indicator for obesity or hypercholesterolemia. [Copyright &y& Elsevier]

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]

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]

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]

A novel in-needle sample preparation device has been developed for the determination of volatile aldehydes in gaseous samples. The needle device is designed for the gas chromatographic (GC) analysis of aldehydes and ketones commonly found in typical in-house environments. In order to prepare the extraction device, a bundle of polymer-coated filaments was longitudinally packed into a specially designed needle. Derivatization reactions were prompted by 2,4-dinitrophenylhydrazine (NDPH) included in the needle, and so the aldehydes and ketones were derivatized to the corresponding hydrazones and extracted with the extraction needle. A reproducible extraction needle preparation process was established, along with a repeatable derivatization/extraction process that ensures the successful determination of aldehydes. The storage performance of the extraction needle was also evaluated at room temperature for three days. The results demonstrate the successful application of the fiber-packed extraction device to the preparation of a gaseous sample of aldehydes, and the future possibility of applying the extraction device to the analysis of in-house environments. [ABSTRACT FROM AUTHOR]

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: For two-dimensional reversed-phase liquid chromatography–gas chromatography (2D RPLC–GC), a specially-designed needle packed with a polymer-coated fibrous stationary phase was introduced as a novel interface. The bundle of synthetic fibers coated with polydimethylsiloxane (PDMS) was packed into the head section of the needle, and served as the extraction medium. Using the post-column dilution of the LC eluent by water and subsequent extraction with the needle interface, the analyte was successfully concentrated to the PDMS phase on the fibrous support in the needle. The concentrated analytes were directly injected to GC system by inserting the needle to a heated GC injector. 2D separations of aliphatic and aromatic hydrocarbons, and also kerosene-extract were performed with the off-line RPLC–GC system interfaced by the needle extractor. The results suggested that the fiber-packed needle interface could be one of the simple and effective approaches to develop an on-line coupled LC–GC system. [Copyright &y& Elsevier]