A simple and efficient method (known as dispersive liquid-liquid microextraction (DLLME)) combined with gas chromatography-flame ionization detector (GC-FID) has been successfully developed for the extraction and determination of mononitrotoluenes (MNTs) in aquatic samples. The effects of parameters such as the nature and volume of the extracting and disperser solvents on the microextraction efficiency were also investigated. The volume of the extracting solvent (chlorobenzene) and that of the disperser solvent (acetonitrile) were obtained to be equal to 10.0 microL and 0.5 mL, respectively, in the optimal microextraction conditions established. Under the optimal conditions, the detection limit of the method was 0.5 microg L(-1) and the relative standard deviations (RSDs%) for determination of the MNTs were in the range of 8.0-9.4. Linearity was found to be in the range of 1-1000 microg L(-1); also, the pre-concentration factors were in the range of 351-357. Finally, the method was applied to determine the trace amounts of the MNTs in several real aquatic samples and satisfactory results were obtained.
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http://dx.doi.org/10.1016/j.jhazmat.2009.09.161 | DOI Listing |
Pharm Res
January 2025
Solid State Pharmaceutics Research Laboratory, Department of Pharmaceutical Sciences and Technology, Birla Institute of Technology, Mesra, Ranchi, 835215, Jharkhand, India.
Improving the bioavailability of poorly water-soluble drugs presents a significant challenge in pharmaceutical development. Amorphous solid dispersions (ASDs) have garnered substantial attention for their capability to augment the solubility and dissolution rate of poorly water-soluble drugs, thereby markedly enhancing their bioavailability. ASDs, characterized by a metastable equilibrium where the active pharmaceutical ingredient (API) is molecularly dispersed, offer enhanced absorption compared to crystalline forms.
View Article and Find Full Text PDFAnal Methods
January 2025
Department of Analytical Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran.
In the present research, an attempt has been made to develop a new thin film microextraction method for the extraction of several polycyclic aromatic hydrocarbons from aqueous samples collected from different industrial units prior to their analysis by gas chromatography combined with a flame ionization detector. In this approach, a thin iron mesh was modified by the formation of iron(II) oxinate on its surface and used for the extraction of analytes without an additional sorbent. For this purpose, first, the mesh was immersed in a sulfuric acid solution and then transferred into an 8-hydroxy quinoline (oxine) solution dissolved in ammonia solution.
View Article and Find Full Text PDFJ Chromatogr A
January 2025
School of Chemistry and Chemical Engineering, Henan University of Technology, Zhengzhou, 450001, China; Henan Key Laboratory of Cereal and Oil Food Safety and Nutrition, Zhengzhou, 450001, China. Electronic address:
Food safety problem caused by aflatoxins (AFs) has become a major concern worldwide. However, due to the complexity of food matrices and the low concentration of analytes, the accurate and sensitive determination of AFs and their precursors in the biosynthetic pathway is extremely challenging, so the development of efficient sample preparation techniques has been urgently required. This paper reviews the recent advances in sample preparation based on some emerging extraction media for the determination of AFs and their precursors in different food samples, including ionic liquids (ILs) and IL-based composites, metal-organic frameworks (MOFs) and covalent organic frameworks (COFs).
View Article and Find Full Text PDFSoft Matter
January 2025
Department of Mathematics, National Institute of Technology Durgapur, Durgapur-713209, India.
The present article deals with the modulation of oscillatory electroosmotic flow (EOF) and solute dispersion across a nanochannel filled with an electrolyte solution surrounded by a layer of a dielectric liquid. The dielectric permittivity of the liquid layer adjacent to supporting rigid walls is taken to be lower than that of the electrolyte solution. Besides, the aforesaid liquid layer may bear additional mobile charges, , free lipid molecules, charged surfactant molecules , which in turn lead to a nonzero charge along the liquid-liquid interface.
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