Pentachlorophenol (PCP) was used as a model compound to explore the potential of desorption chemical ionization (DCI) in the determination of polychlorinated pesticides using membrane introduction mass spectrometry (MIMS). A direct insertion membrane probe was modified so that a chemical ionization plasma could be established at the membrane surface. Using selected ion monitoring (SIM) in a tandem triple quadrupole mass spectrometer with isobutane chemical ionization (CI), the PCP detection limit under positive chemical ionization is 20 ppb whereas negative CI gives detection limits in the low ppb range. This performance is achieved without any pre-treatment or derivatization of the sample. Negative ion CI gives a signal that is linear over a concentration range of 2-1000 ppb. Comparison of data obtained with low ppb samples of 2,4,6-trichlorophenol, 2,3,4,6-tetrachlorophenol and pentachlorophenol suggests that the sensitivity of this analytical procedure increases with increase in the number of electronegative substituents in the molecule.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1039/b206350f | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Electrochemically Driven Selective Olefin Epoxidation by Cobalt-TAML Catalyst.
J Am Chem Soc
January 2025
Department of Chemistry, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, South Korea.
Epoxides are versatile chemical intermediates that are used in the manufacture of diversified industrial products. For decades, thermochemical conversion has long been employed as the primary synthetic route. However, it has several drawbacks, such as harsh and explosive operating conditions, as well as a significant greenhouse gas emissions problem.
View Article and Find Full Text PDFREACH assessment of humans exposed to chemicals indirectly via the environment: screening modeling in EUSES versus state of the science.
Integr Environ Assess Manag
January 2025
Henkel AG & Co KGaA, Düsseldorf, Germany.
The assessment of humans indirectly exposed to chemicals via the environment (HvE) is an assessment element of the Registration, Evaluation, Authorisation, and Restriction of Chemicals (REACH) regulation. The European Union System for the Evaluation of Substances (EUSES) is the default screening tool, aimed at prioritizing chemicals for further refinement/higher tier assessment. This review summarizes the approach used in EUSES, evaluates the state of the science in human exposure modeling via the environment, and identifies areas for further research to strengthen the confidence and applicability of EUSES for assessing HvE.
View Article and Find Full Text PDFIntegrating ex situ biomimetic extraction analyses into contaminated sediment assessment and management decisions.
Integr Environ Assess Manag
January 2025
Department of Civil, Environmental, and Construction Engineering, Texas Tech University, Lubbock, TX, United States.
This study evaluated a novel ex situ passive sampling biomimetic extraction (BE) method to estimate toxic potency in sediments. Gas chromatography with flame ionization detection (GC-FID) analysis of polydimethylsiloxane fibers equilibrated with field sediments was used to quantify bioavailable polyaromatic hydrocarbons (PAHs) and other unresolved, site-specific contaminant mixtures. This method is biomimetic because contaminants partition to the fiber based on hydrophobicity and abundance, and GC-FID quantification accounts for all constituents absorbed to the fiber that may contribute to toxicity.
View Article and Find Full Text PDFDetermination of Reactive Dyes in Coloring Foodstuff, Fruit Juice Concentrates, and Meat Products by Reductive Azo-Bond Cleavage and LC-ESI-MS/MS Analysis.
J Agric Food Chem
January 2025
Institute of Food Chemistry, Technische Universität Braunschweig, Schleinitzstraße 20, 38106 Braunschweig, Germany.
Visually appealing foods are often associated by consumers with subjective quality features, such as freshness, palatability, and shelf life. In the past, there have been repeated violations in which regulations on the use of pigments in food were ignored and/or unauthorized or toxic dyes (e.g.
View Article and Find Full Text PDFCationic Polyhedral Chalcogenaboranes: Activation without breaking Wade's Rules.
Angew Chem Int Ed Engl
January 2025
University Pardubice Faculty of Chemical Technology: Univerzita Pardubice Fakulta Chemicko-Technologicka, Department of General and Inorganic Chemistry, CZECHIA.
Wade's rules are a well-established tool for the description of the geometry of inorganic clusters. Among others, they state that a decrease or increase in charge is always accompanied by a change in the number of skeletal electron pairs (SEPs). This work reports the synthesis of the first cationic chalcogenaboranes closo-[12-X-2-IPr-1-EB11H10]BF4 (X = H, I; E = S, Se 3a/b, 4a/b) featuring the same SEP count as their neutral precursors, EB11H11, but bearing a positive charge.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!