In the present work, the footprint of carbonyl compounds in hand scent was achieved by a miniaturized method consisting of sampling with cotton gauze, extraction and derivatization using 2,4-dinitrophenylhydrazine (DNPH) and preconcentration, separation and detection by in-tube solid-phase microextraction (IT-SPME) coupled to nano-liquid chromatography/Uv-vis diode array detection. The coupling IT-SPME-nanoLC-DAD was solved by using a two-valve system: the first valve for loading the sample and the second one to perform IT-SPME. To this aim, a nanoparticle-based capillary column was employed. Firstly, the transfer time from the load loop to the NP-based capillary column in the IT-SPME system was optimized. Additionally, the conditioning and clean-up steps were also studied. For the chromatographic separation of DNPH derivatives, gradient elution mode (acetonitrile/water) and a C nanocolumn were employed. The detection limits achieved were between 0.5 and 1.5 μg/L and % rsd was lower than 5% for quantification limits. The proposed methodology gave rise to different chromatographic profiles of carbonyl compounds in the hand scent of several volunteers. These profiles were obtained by estimating the relative peak area of selected carbonyls in hand scent. Nonanal, decanal and dodecanal and other low polarity carbonyl compounds (unknown hydrazones) were detected in the odor profiles.
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http://dx.doi.org/10.1016/j.chroma.2019.03.007 | DOI Listing |
J Org Chem
January 2025
Department of Chemistry, Indian Institute of Science Education and Research, Dr. Homi Bhabha Road, Pashan, Pune 411008, India.
β-Addition products are common in conjugate addition reactions consisting of α,β-unsaturated carbonyl compounds. Here, we are reporting an uncommon α-addition product as a major product in the thioacetic acid conjugate addition reaction on a peptide consisting of ()-α,β-unsaturated γ-amino acids. In addition, we observed highly diastereoselective β-addition products from the thiophenol and thioethanol conjugate addition reaction on peptides.
View Article and Find Full Text PDFPhys Chem Chem Phys
September 2020
GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstrasse 1, 64291 Darmstadt, Germany.
With the aim to render assistance to future experiments on the production and investigation of chemical properties of carbonyl compounds of element 109, Mt, calculations of the molecular properties of M(CO) and MH(CO), where M = Rh, Ir, and Mt, and of the products of their decomposition, M(CO) and MH(CO), were performed using relativistic Density Functional Theory and Coupled-Cluster methods implemented in the ADF, ReSpect and DIRAC software suites. According to the results, MH(CO) should be formed at experimental conditions from the M atom with a mixture of CO and He gases. The calculated first M-CO bond dissociation energies (FBDE) of Mt(CO) and MtH(CO) turned out to be significantly weaker than those of the corresponding Ir homologs.
View Article and Find Full Text PDFRSC Adv
January 2025
Faculty of Systems Engineering, Wakayama University 930 Sakaedani Wakayama 640-8510 Japan
C NMR chemical shifts ((C)) were analysed MO theory, together with the origin, using (C), (C) and (C), where C was selected as the standard for the analysis since (C: C) = 0 ppm. An excellent relationship was observed between (C) and the charges on C for (C, C, C, C and C) and (C, CH , CH and CH). However, such a relationship was not observed for the carbon species other than those above.
View Article and Find Full Text PDFOrg Biomol Chem
January 2025
School of Life Science and Engineering, School of Chemistry, Southwest Jiaotong University, Chengdu, 610031, China.
Under mild visible light conditions, formates facilitate C-O cleavage the EDA complex and SCS strategy, yielding α-carbonyl alkyl radicals. These radicals then react with olefins under air conditions, leading to the synthesis of diaryl 1,4-dicarbonyl compounds. Mechanistic studies reveal that α-formyloxy ketone is generated by the reaction between α-brominated acetophenone and formates, followed by the formation of the EDA complex.
View Article and Find Full Text PDFBiol Res
January 2025
Department of Biotechnology, Genetics and Cell Biology, State University of Maringá, Maringá, Paraná, 87020-900, Brazil.
Bees are essential pollinators that contribute to maintaining biodiversity and increasing agricultural production. However, by foraging on agricultural crops, bees may become contaminated with compounds used for pest control. In this study, we exposed bee (Apis mellifera L.
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