A fast and accurate analytical method, which uses commercially available adsorbents (Tenax TA, Carbotrap B and C, and Carbosieve S-III), was developed for the sampling and determination of aromatic hydrocarbons, chloroaromatic compounds, and 2,3,7,8-tetrachlorodibenzo-p-dioxin. The breakthrough volume data show that Carbotrap C has a good capacity for compounds of high molecular weight, whereas Carbosieve S-III and Tenax TA are efficient for volatile compounds. The organic components are thermally desorbed and transferred to a gas chromatograph/mass spectrometer. Importantly, thermal desorption avoids conventional solvent extraction procedures and also allows reuse of adsorbent tubes. Preliminary results for recovery of analytes from tubes packed with single adsorbent prove that a single-adsorbent bed is not capable of sampling a wide range of compounds. The best method to obtain the desired collection and desorption properties is to use adsorbent tubes containing several different materials. The results of optimization studies are summarized.
Download full-text PDF |
Source |
---|
J Chromatogr A
December 2024
School of Energy and Power Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China. Electronic address:
The evolution of precursors to form secondary organic aerosol (SOA) is still a challenge in atmospheric chemistry. Chamber experiments were conducted to simulate the ambient OH oxidation of naphthalene and α-pinene, which are typical markers of anthropogenic and biogenic emissions. Particulate matters were sampled by quartz filters and were analyzed by comprehensive two-dimensional gas chromatography (GC×GC) coupled with a thermal desorption system (TD) and a mass spectrometer (MS).
View Article and Find Full Text PDFGels
December 2024
Research Center for Green Energy Systems, Department of Mechanical Engineering, Gachon University, Seongnam-si 13120, Republic of Korea.
This study aims to develop efficient and sustainable hydrogels for dye adsorption, addressing the critical need for improved wastewater treatment methods. Carboxymethyl cellulose (CMC)-based hydrogels grafted with AAc were synthesized using gamma radiation polymerization. Various AAc to CMC ratios (5:5, 5:7.
View Article and Find Full Text PDFAnal Bioanal Chem
December 2024
Division of Pulmonary, Critical Care and Sleep Medicine, University of California, Davis, Sacramento, CA, USA.
Metabolically active cells emit volatile organic compounds (VOCs) that can be used in real time to non-invasively monitor the health of cell cultures. We utilized these naturally occurring VOCs in an adapted culture method to detect differences in culturing Chinese hamster ovary (CHO) cells with and without Staphylococcus epidermidis and Aspergillus fumigatus contaminations. The VOC emissions from the cell cultures were extracted and measured from the culture flask headspace using polydimethylsiloxane (PDMS)-coated Twisters, which were subjected to thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) analysis.
View Article and Find Full Text PDFPoult Sci
December 2024
Adaptation Physiology Group, Wageningen University & Research, P.O. Box 338, 6700 AH Wageningen, The Netherlands.
Continuous, non-invasive, and objective methods to detect flock-level responses to stressors, including intestinal health deviations, are currently lacking in poultry. This proof of principle study investigated the potential of manure odor profiling in monitoring stress responses in Lohmann Brown Classic, Lohmann LSL Classic and Lohmann LSL Lite layer pullets. Stressors were represented by a Salmonella vaccination given to the pullets at wk 3 of age (Dataset 1 and Dataset 2) and wk 16 of age (Dataset 4) and a viral/bacterial vaccine cocktail given at wk 12 of age (Dataset 3).
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
Jilin University, Chemistry, 2699 Qianjin Street, 130012, Changchun, CHINA.
Green ammonia synthesis using fluctuating renewable energy supply in decentralized process is a goal that has been long sought after. Ammonia synthesis with non-thermal plasma under mild conditions is a promising technology, but it faces the critical challenge of low energy efficiency. Herein, we develop an easily-scalable AuCu3/Cu catalyst, which consists of a decimeter-scale metallic Cu antenna and nano-scale AuCu3 catalytic sites on metallic Cu surface, significantly enhancing the energy efficiency and ammonia yield in a radio-frequency (RF) plasma system.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!