A simple method for establishing calibration curves with sorbent-filled thermal desorption tubes has been demonstrated for nitroaromatic and nitramine vapor samples using a thermal desorption system with a cooled inlet system (TDS-CIS), which was coupled to a gas chromatograph (GC) with an electron capture detector (ECD). The method relies upon the direct liquid deposition of standard solutions onto the glass frit at the head of sorbent-filled thermal desorption tubes. Linear calibration results and ideal system conditions for the TDS-CIS-GC-ECD were established for mixtures containing both cyclotrimethylenetrinitramine, a.k.a. RDX, and 2,4,6-trinitrotoluene (TNT). Because of the chemical characteristics of RDX, a higher TDS-CIS flow rate relative to the optimized approach for TNT was required for efficient RDX desorption. Simultaneous quantitation of TNT and RDX using the direct liquid deposition method with optimized instrumentation parameters for RDX were compared to results from a standard split/splitless GC inlet and a CIS.
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http://dx.doi.org/10.1016/j.chroma.2013.01.051 | DOI Listing |
Nano Lett
January 2025
Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, College of Material Sciences and Chemical Engineering, Harbin Engineering University, Harbin 150001, P. R. China.
Dual atomic nanozymes (DAzymes) are promising for applications in the field of tumor catalytic therapy. Here, integrating with ultrasmall FeC nanoclusters, asymmetric coordination featuring Janus Zn-Fe dual-atom sites with an ON-Fe-Zn-N moiety embedded in a carbon vacancy-engineered hollow nanobox (Janus ZnFe DAs-FeC) was elaborately developed. Theoretical calculation revealed that the synergistic effects of Zn centers acting as both adsorption and active sites, oxygen-heteroatom doping, carbon vacancy, and FeC nanoclusters jointly downshifted the d-band center of Fe 3d orbitals, optimizing the desorption behaviors of intermediates *OH, thereby significantly promoting catalytic activity.
View Article and Find Full Text PDFAnal Methods
January 2025
CSIR-Central Salt and Marine Chemicals Research Institute (CSIR-CSMCRI), G. B. Marg, Bhavnagar, 364 002, India.
In this study, magnesium-doped lithium manganese oxide nanoparticles were prepared through a solid-state reaction technique, and their surface was modified with mesoporous silica. The surface-modified material exhibited a significantly enhanced BET surface area from 5.791 to 66.
View Article and Find Full Text PDFJ Chromatogr A
January 2025
Ministry of Education Key Laboratory of Analytical Science for Food Safety and Biology, Fujian Provincial Key Laboratory of Analysis and Detection Technology for Food Safety, College of Chemistry, Fuzhou University, Fuzhou, Fujian, 350108, China. Electronic address:
Benzophenone derivatives (BPs), as synthetic chemicals widely used in personal care products, have drawn increasing attention due to their potential health risks. However, monitoring BPs in biological samples remains challenging due to their complex matrices and the deficiency in sensitivity and selectivity in current methods. Herein, a method combining hierarchically flower-like hollow covalent organic frameworks (HFH-COFs) with high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was established for the enrichment and detection of BPs in serum samples.
View Article and Find Full Text PDFMaterials (Basel)
January 2025
Departamento de Química Ambiental, Universidad Católica de la Santísima Concepción, Concepción 4070129, Chile.
This study evaluated the stability and reusability of amino-functionalized nanocellulose aerogels as CO-adsorbent materials. The modified aerogels, synthesized via a controlled silylation using N-[3-(trimethoxysilyl) propyl] ethylenediamine (DAMO), demonstrated excellent thermal stability up to 250 °C (TGA) and efficient CO adsorption through chemisorption, which was the main adsorption mechanism. The performance of the aerogels was assessed using both adsorption isotherms and the decay pressure technique, revealing that CO adsorption capacity increased with higher amino group loading (4.
View Article and Find Full Text PDFEcotoxicol Environ Saf
January 2025
National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing 100021, China; China CDC Key Laboratory of Environment and Population Health, Beijing 100021, China. Electronic address:
Cognitive fatigue in specific occupations may present a risk to personal safety. The study aimed to explore the characteristic volatile organic compounds (VOCs) in exhaled breath in response to cognitive fatigue, to provide a scientific basis for the non-invasive exhaled breath diagnostic techniques for cognitive fatigue assessing. Thirty healthy young adults were recruited and assigned to complete two 1.
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