The gas chromatography of the heptafluorobutyryl derivatives of carbofuran, 3-ketocarbofuran and 3-hydroxycarbofuran is examined with electrolytic conductivity detection (halogen mode). The reaction consists of heating the compounds with heptafluorobutyric anhydride in the presence of trimethylamine catalyst. Although as little as 200 pg of carbofuran, 400 pg of 3-ketocarbofuran and 100 pg of 3-hydroxycarbofuran can be detected by electrolytic conductivity, the minimum detectable quantities by electron capture are about 20-fold less for each derivative. Application to the analysis of carbofuran and 3-ketocarbofuran in corn, potato, turnip and wheat is carried out. This technique is compared to direct gas chromatography in the nitrogen mode and to direct high-pressure liquid chromatography with UV detection at 254 nm using extracts of field-treated turnips.
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http://dx.doi.org/10.1016/s0021-9673(00)98005-1 | DOI Listing |
RSC Adv
January 2023
Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University Xiamen 361005 P. R. China
Six lanthanide complexes constructed from two chiral β-diketonates (d/l-fbc = 3-heptafluorobutyry(+)/(-)-camphorate), the stilbene derivative ()-','-bis(pyridin-2-ylmethyl)-4-styrylbenzoyl hydrazide (L), a trifluoroacetate anion (CFCO ), and one water molecule, namely [Ln(d/l-fbc)(L)(CFCO)]·HO (LnCHFNO, Ln = La (1, d-fbc), La (2, lfbc), Sm (3, d-fbc), Eu (4, d-fbc), Eu (5, lfbc), and Tb (6, d-fbc), were synthesized and characterized by single-crystal X-ray diffraction, H-NMR, elemental analysis, IR and UV-vis spectroscopy, and thermal gravimetric analysis. The photoisomerization reactions of these complexes were systematically studied by means of experimental and theoretical calculations. Crystals of complexes 1, 2, 3, and 4 were obtained and belong to the monoclinic crystal system and the 2 chiral space group.
View Article and Find Full Text PDFRapid Commun Mass Spectrom
June 2020
VERTOX - Biochemistry Division, Defence Research and Development Establishment, Jhansi Road, Gwalior, 474002, Madhya Pradesh, India.
Rationale: Analytical methods for the detection and identification of half nitrogen mustards (halfNMs), i.e., partially hydrolyzed products of nitrogen mustards (pHpNMs), using silyl derivatives are often associated with low sensitivity and selectivity.
View Article and Find Full Text PDFTheranostics
July 2019
School of Life Sciences, Tianjin University, Tianjin 300072, China.
Low water solubility and poor selectivity are two fundamental limitations that compromise applications of near-infrared (NIR) fluorescent probes. Here, a simple strategy that can resolve these problems simultaneously was developed by using a novel hybrid protein named RGD-HFBI that is produced by fusion of hydrophobin HFBI and arginine-glycine-aspartic acid (RGD) peptide. This unique hybrid protein inherits self-assembly and targeting functions from HFBI and RGD peptide respectively.
View Article and Find Full Text PDFMedchemcomm
July 2017
Laboratory of Stem Cells for Tissue Engineering , IRCCS Policlinico San Donato, Piazza Malan 2 , 20097 San Donato Milanese , Milan , Italy . Email: ; Email: ; Tel: +0252774674.
Newcastle Disease Virus (NDV), belonging to the Paramyxoviridae family, causes a serious infectious disease in birds, resulting in severe losses in the poultry industry every year. Haemagglutinin neuraminidase glycoprotein (HN) has been recognized as a key protein in the viral infection mechanism, and its inhibition represents an attractive target for the development of new drugs based on sialic acid glycals, with the 2-deoxy-2,3-didehydro-d--acetylneuraminic acid (Neu5Ac2en) as their backbone. Herein we report the synthesis of several Neu5Ac2en glycals and of their perfluorinated C-5 modified derivatives, including their respective stereoisomers at C-4, together with evaluation of their antiviral activity.
View Article and Find Full Text PDFAnal Chem
January 2015
Institute of Chemistry, Departments of †Analytical and ‡Inorganic Chemistry, L. Eötvös University, 1117, Pázmány Péter sétány 1/A, Budapest, Hungary.
A novel, selective acylation of primary phenylalkyl amines (PPAAs) using hexamethyldisilazane (HMDS) and perfluorocarboxylic acids (PFCAs) is noted. Couples, like HMDS and trifluoroacetic acid, HMDS and pentafluoropropionic acid, or HMDS and heptafluorobutyric acid trigger PPAAs’ quantitative acylation. Processes’ selectivity was characterized by applying all couples to derivatize benzyl, 2-phenylethyl, 3-phenylpropyl, 4-phenylbutyl amines, and their relevant substituted versions.
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