Liquid-liquid extraction systems for VIV/V containing 2,3-dihydroxynaphtahlene (DN) and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (thiazolyl blue, MTT) were studied. The optimum conditions for VIV and VV extraction were found. VIV is extracted in chloroform as a 1:2:2 complex (V:DN:MTT) with lmax = 570 nm and e570 = 2.9´104 dm3 mol-1 cm-1. However, this wavelength was found unsuitable for precise spectrophotometric measurements due to time dependent absorbance changes. VV forms predominantly a 1:1:1 complex with lmax = 335 nm. The calibration graph for this oxidation state is linear in the range of 0.06-1.5 mg cm-3. The molar absorptivity, Sandell's sensitivity and limit of detection were calculated to be 1.6 ´ 104 dm3 mol-1 cm-1, 3.2 ng cm-2 and 0.02 mg cm-3, respectively. The ground-state equilibrium geometries of the anionic parts of the extracted ion-associates, [VIVO(DN2-)2]2-and [VVO2(DN2-)]-, were optimized at the BLYP/6-31++G* level of theory.
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http://dx.doi.org/10.17344/acsi.2018.4225 | DOI Listing |
Rev Argent Microbiol
January 2025
Instituto De Química Biológica de la Facultad de Ciencias Exactas y Naturales-CONICET, Buenos Aires, Argentina; Departamento de Química Biológica, FCEyN-UBA, Buenos Aires, Argentina. Electronic address:
DNA extraction is crucial for conducting procedures, such as whole-genome sequencing, which demand methods that are reproducible and cost-effective. Lysing Staphylococcus aureus cells is particularly challenging due to their peptidoglycan layer that is resistant to common treatments. Traditional methods involve costly enzymatic lysis using lysostaphin.
View Article and Find Full Text PDFJ Chromatogr A
January 2025
College of Food Science and Engineering, Qingdao Agricultural University, Qingdao, 266109, China; Academy of Dongying Efficient Agricultural Technology and Industry on Saline and Alkaline Land in Collaboration with Qingdao Agricultural University, Dongying 257343, China. Electronic address:
Efficient enrichment of analytes and purification of matrices are crucial for the highly sensitive detection and monitoring of pesticides in traditional Chinese herbs. This work prepared magnetic ionic liquid-controlled covalent organic framework (IL-COF@FeO) as the sorbent via a simple in-situ precipitation polymerization and thiolene "click" strategy. The IL-COF@FeO exhibited remarkable adsorption performance towards pyrethroids within 5 min.
View Article and Find Full Text PDFFood Chem X
January 2025
Academy of National Food and Strategic Reserves Administration, NFSRA Key Laboratory of Grain and oil quality and safety, Beijing 100037, China.
The contamination of Alternaria toxins poses a potential risk to human health. This study developed a rapid, efficient, and environmentally friendly method for the simultaneous determination of five types of Alternaria toxins in wheat using high-precision and stable isotope liquid chromatography tandem mass spectrometry. The comparison between dilution method and solid-phase extraction method shows that the former achieves satisfactory results with a simple and convenient sample purification method.
View Article and Find Full Text PDFJ Chromatogr Sci
January 2025
Department of Chemistry & Biochemistry, Ohio University, Athens, OH, USA.
The valid method was developed for analyzing empagliflozin in serum/plasma/urine using a molecularly imprinted ghost polymer-solid-phase extraction approach (MISPE) with liquid chromatographic methodology. Methacrylic acid (MAA) was used as the monomer, 2,2 azobis isobutyronitrile as the initiator and ethylene glycol dimethacrylate as the cross-linker in the free radical polymerization procedure. Empagliflozin was loaded onto the polymer and eluted with 1 mL of a 9:1 MeOH:acetic acid solution.
View Article and Find Full Text PDFJ Chromatogr B Analyt Technol Biomed Life Sci
January 2025
An easy applicable and selective sample preparation technique has been developed for trace and simultaneously analysis of Glipizide (GLP) and Pravastatin (PST) molecules in biological matrices based on magnetic solid phase extraction (MSPE) and high-performance liquid chromatography (HPLC). A new magnetic adsorbent including FeO@TEOS-Melamine has been synthetized and characterized for extraction studies. Experimental variables of MSPE were examined and optimized step by step such as pH, adsorption and desorption conditions, time effect, etc.
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