Long sample extraction time is usually necessary in the analysis of volatile flavour compounds to achieve high extraction efficiency. However, the long extraction time reduces sample throughput, which results in waste of labour and energy. Therefore, in this study, an improved headspace-stir bar sorptive extraction was developed to extract volatile compounds with varying polarities in a short time.
View Article and Find Full Text PDFPolybrominated diphenyl ethers (PBDEs) are commonly used as flame retardants in daily household products and have been found to be detrimental to human and animal health. Being highly stable, accumulation can take place easily in the environment. In our previous studies, an innovative sample preparation method named miniscale liquid-liquid extraction (msLLE) coupled to full evaporation dynamic headspace (FEDHS) concentration was developed, and then successfully coupled to an online water sampling system, allowing full automation from water sampling to sample preparation, sample detection and analysis.
View Article and Find Full Text PDFThree modes of facilitating mini-scale-liquid-liquid-extraction (msLLE) prior to automated integration with full evaporation dynamic headspace (FEDHS) extraction were evaluated in this work. For msLLE, 1.2 mL of dichloromethane (DCM) was added to a conical-bottomed vial containing 7 mL of aqueous sample.
View Article and Find Full Text PDFSorptive extraction techniques have experienced increased popularity, but they face limitations in dynamic range and sensitivity. In this study, a new method combining stir bar sorptive extraction (SBSE) and thin-film solid-phase microextraction (TFSPME) was developed, and optimization for extraction temperature (70 °C) and time (120 min) was carried out. Polydimethylsiloxane (PDMS)-coated SBSE and PDMS/carboxen (PDMS/CAR)-coated TFSPME were used, and both headspace and direct immersion extraction modes were also studied.
View Article and Find Full Text PDFAn environmentally friendly method of etching a stainless steel plunger wire, to replace the conventional hydrofluoric acid approach, was developed for plunger-in-needle liquid phase-microextraction (PIN-LPME). The one-step etching procedure was performed by immersing the plunger wire in a ferric chloride-hydrochloric acid (FeCl-HCl) solution. The etched wire was then used for LPME as the organic solvent holder.
View Article and Find Full Text PDFA fully automated analytical platform that seamlessly integrates online water sampling-sample preparation-gas chromatography-mass spectrometry (GC-MS) was developed for ultraviolet (UV) filters in this work. The online water sampling system consisted of a conventional sample vial (slightly modified to have both inlet and outlet ports), two tubings and a peristaltic pump, which controlled the water flow into and out of the vial. The sample preparation segment consists of miniscale liquid-liquid extraction (msLLE), coupled to full evaporation dynamic headspace concentration (FEDHS) on a commercial dual-arm autosampler.
View Article and Find Full Text PDFA new sample preparation approach of combining a miniscale version of liquid-liquid extraction (LLE), termed miniscale-LLE (msLLE), with automated full evaporation dynamic headspace extraction (FEDHS) was developed. Its applicability was demonstrated in the extraction of several polycyclic aromatic hydrocarbons (PAHs) (acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, and pyrene) from aqueous samples. In the first step, msLLE was conducted with 1.
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