Publications by authors named "Wu-Hsun Chung"

6 Publications

  • Page 1 of 1

Determination of benzotriazole and benzothiazole derivatives in marketed fish by double-vortex-ultrasonic assisted matrix solid-phase dispersion and ultrahigh-performance liquid chromatography-high resolution mass spectrometry.

Food Chem 2020 Dec 10;333:127516. Epub 2020 Jul 10.

Department of Chemistry, National Central University, Chung-Li 320, Taiwan. Electronic address:

Benzotriazoles (BTRs) and benzothiazoles (BTs) are two groups of emerging concern and high production volume contaminants. Via the biomagnification of the food web, they could jeopardize human health. In this work, rapid determining the presence of five BTRs and two BTs in marketed fish was performed by a novel double-vortex-ultrasonic assisted matrix solid-phase dispersion (DVUA-MSPD) and UHPLC-electrospray ionization (+)-quadrupole time-of-flight mass spectrometry detection. Unlike traditional MSPD, we simplified the method without the use of mortar/pestle and SPE-column procedures. The DVUA-MSPD factors were screened by a multilevel categorical design, and then optimized by Box-Behnken Design plus with response surface methodology. The limits of quantification were 0.15-2 ng g (dry weight). The satisfactory average recovery ranged from 70% to 93% with RSDs less than 9%. The developed method was successfully applied for the rapid determination of selected BTRs and BTs in fish samples at trace-level.
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http://dx.doi.org/10.1016/j.foodchem.2020.127516DOI Listing
December 2020

Dual-vortex-assisted matrix solid-phase dispersion coupled with isotope-dilution ultrahigh-performance liquid chromatography-high resolution mass spectrometry for the rapid determination of parabens in indoor dust samples.

J Chromatogr A 2019 Nov 19;1605:460367. Epub 2019 Jul 19.

Department of Chemistry, National Central University, Chung-Li 320, Taiwan. Electronic address:

A reliable and straightforward method was developed for the rapid determination of nine parabens (methyl-, ethyl-, propyl-, butyl-, isopropyl-, isobutyl-, pentyl-, hexyl-, and benzyl-parabens) in indoor dust by a mortar/pestle-free and column-free dual-vortex-assisted matrix solid-phase dispersion (DVA-MSPD) technique. After that, they were determined by isotope-dilution ultrahigh-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-qTOF-MS, or called UHPLC-HRMS) and operating in negative electrospray ionization mode. Optimization of the DVA-MSPD was done using Box-Behnken Design along with response surface methodology. Validation was done by measuring and calculating selectivity, limits of detection (LOD), limits of quantitation (LOQs), precision and trueness (accuracy) of intra- and inter-day analysis. The LOQs of the method ranged from 0.9 to 2.8 ng/g. High precisions for both intra- and inter-day analysis were obtained ranging from 1 to 8%. Excellent trueness (or mean extraction recovery) varied from 93 to 104%. The DVA-MSPD combined with isotope-dilution UHPLC-qTOF-MS was successfully applied to determine parabens in indoor dust samples from office rooms and private houses, and the total concentrations ranged from 55 to 686 ng/g.
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http://dx.doi.org/10.1016/j.chroma.2019.460367DOI Listing
November 2019

Ultrasound-assisted emulsification microextraction for rapid determination of unmetabolized synthetic polycyclic and nitro-aromatic musks in human urine.

J Chromatogr B Analyt Technol Biomed Life Sci 2018 Aug 20;1092:440-446. Epub 2018 Jun 20.

Department of Chemistry, National Central University, Chung-Li 320, Taiwan. Electronic address:

An effective method to rapidly determine the presence of seven unmetabolized synthetic musks in human urine samples is developed. The target musks are five synthetic polycyclic musks (i.e., celestolide (ADBI), phantolide (AHMI), traseolide (ATII), galaxolide (HHCB), tonalide (AHTN)), and two nitro-aromatic musks (i.e., musk xylene (MX) and musk ketone (MK)). The method involved an ultrasound-assisted emulsification microextraction (USAEME) coupled with gas chromatography-mass spectrometry (GC-MS). The factors that affect USAEME efficiency were optimized in detail, and the optimized procedure involved the rapid injection of 50 μL of carbon tetrachloride into 1.0 mL of urine sample (contained 0.1-g of sodium chloride) in a conical bottom glass tube. After 1.0 min ultrasonication and 3 min centrifugation (at 7000 rpm), the sedimented extract 10 μL was directly injected into the GC-MS system. The limits of quantitation (LOQs) varied from 0.1 to 0.5 ng/mL. The precisions for both repeatability and reproducibility were <8%. The trueness varied from 79 to 96% with the RSD ranging from 2 to 8%. The total concentrations of the seven unmetabolized target musks in collected human urine samples were in the range from 0.93 to 3.74 ng/mL. HHCB and AHTN were detected in all the collected samples, and the daily excretion doses were evaluated.
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http://dx.doi.org/10.1016/j.jchromb.2018.06.042DOI Listing
August 2018

Vortex-assisted liquid-liquid microextraction for the rapid screening of short-chain chlorinated paraffins in water.

J Sep Sci 2016 Jan 21;39(2):427-32. Epub 2015 Dec 21.

Department of Chemistry, National Central University, Chung-Li 320, Taiwan.

The rapid screening of trace levels of short-chain chlorinated paraffins in various aqueous samples was performed by a simple and reliable procedure based on vortex-assisted liquid-liquid microextraction combined with gas chromatography and electron capture negative ionization mass spectrometry. The optimal vortex-assisted liquid-liquid microextraction conditions for 20 mL water sample were as follows: extractant 400 μL of dichloromethane; vortex extraction time of 1 min at 2500 × g; centrifugation of 3 min at 5000 × g; and no ionic strength adjustment. Under the optimum conditions, the limit of quantitation was 0.05 μg/L. Precision, as indicated by relative standard deviations, was less than 9% for both intra- and inter-day analysis. Accuracy, expressed as the mean extraction recovery, was above 91%. The vortex-assisted liquid-liquid microextraction with gas chromatography and electron capture negative ionization mass spectrometry method was successfully applied to quantitatively extract short-chain chlorinated paraffins from samples of river water and the effluent of a wastewater treatment plant, and the concentrations ranged from 0.8 to 1.6 μg/L.
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http://dx.doi.org/10.1002/jssc.201500991DOI Listing
January 2016

Optimization of dispersive micro solid-phase extraction for the rapid determination of benzophenone-type ultraviolet absorbers in aqueous samples.

J Chromatogr A 2015 Sep 1;1411:17-22. Epub 2015 Aug 1.

Department of Chemistry, National Central University, Chung-Li 320, Taiwan. Electronic address:

A solvent-free method for the rapid analysis of six benzophenone-type UV absorbers in water samples is described. The method involves the use of dispersive micro solid-phase extraction (DmSPE) followed by the simultaneous silylation and thermal desorption (SSTD) gas chromatography-mass spectrometry (GC-MS) operating in the selected-ion-storage (SIS) mode. A Plackett-Burman design was used for screening and a central composite design (CCD) for optimizing the significant factors was applied. The optimal experimental conditions involved immersing 1.5mg of the Oasis HLB adsorbent in a 10mL portion of water sample. After vigorous shaking for 1min, the adsorbents were transferred to a micro-vial, and were dried at 122°C for 3.5min, after cooling, 2μL of the BSTFA silylating reagent was added. For SSTD, the injection-port temperature was held at 70°C for 2.5min for derivatization, and the temperature was then rapidly increased to 340°C to allow the thermal desorption of the TMS-derivatives into the GC for 5.7min. The limits of quantitation (LOQs) were determined to be 1.5-5.0ng/L. Precision, as indicated by relative standard deviations (RSDs), was equal or less than 11% for both intra- and inter-day analysis. Accuracy, expressed as the mean extraction recovery, was between 87% and 95%. A preliminary analysis of the municipal wastewater treatment plant (MWTP) effluent and river water samples revealed that 2-hydroxy-4-methoxybenzophenone (BP-3) was the most common benzophenone-type UV absorber present. Using a standard addition method, the total concentrations of these compounds ranged from 5.1 to 74.8ng/L.
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http://dx.doi.org/10.1016/j.chroma.2015.07.106DOI Listing
September 2015

Dispersive micro solid-phase extraction for the rapid analysis of synthetic polycyclic musks using thermal desorption gas chromatography-mass spectrometry.

J Chromatogr A 2013 Sep 24;1307:34-40. Epub 2013 Jul 24.

Department of Chemistry, National Central University, Chung-Li 320, Taiwan; Department of Chemical Engineering, Army Academy ROC, Chung-Li 320, Taiwan.

A simple and solvent-free method for the rapid analysis of five synthetic polycyclic musks in water samples is described. The method involves the use of dispersive micro solid-phase extraction (D-μ-SPE) coupled with direct thermal desorption (TD) gas chromatography-mass spectrometry (GC-MS) operating in the selected-ion-storage (SIS) mode. The parameters affecting the extraction efficiency of the target analytes from water sample and the thermal desorption conditions in the GC injection-port were optimized using a central composite design method. The optimal extraction conditions involved immersing 3.2mg of a typical octadecyl (C18) bonded silica adsorbent (i.e., ENVI-18) in a 10mL water sample. After extraction by vigorously shaking for 1.0min, the adsorbents were collected and dried on a filter. The adsorbents were transferred to a micro-vial, which was directly inserted into GC temperature-programmed injector, and the extracted target analytes were then thermally desorbed in the GC injection-port at 337°C for 3.8min. The limits of quantitation (LOQs) were determined to be 1.2-3.0ng/L. Precision, as indicated by relative standard deviations (RSDs), was less than 9% for both intra- and inter-day analysis. Accuracy, expressed as the mean extraction recovery, was between 74 and 90%. A preliminary analysis of the river water samples revealed that galaxolide (HHCB) and tonalide (AHTN) were the two most common synthetic polycyclic musks present. Using a standard addition method, their concentrations were determined to in the range from 11 to 140ng/L.
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http://dx.doi.org/10.1016/j.chroma.2013.07.074DOI Listing
September 2013
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