Search

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]

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]

• 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]