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51.
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Four positionally isomeric 2-(2-quinolinyl)-1H-indene-1,3(2H)-dionedisulfonic acids (SA) and one triSA, components of the color additive Quinoline Yellow (QY, Color Index No. 47005), were isolated from the dye mixture by affinity-ligand pH-zone-refining counter-current chromatography (CCC) through complementary use of ion-exchange and ion-pair reagents as the ligand. The added ligands facilitated the partitioning of the very polar polysulfonated components into the organic stationary phase of the two-phase solvent systems that consisted of isoamyl alcohol–methyl tert-butyl ether–acetonitrile–water (3:5:1:7), (3:4:1:7) or (3:1:1:5). Thus, separation of a 5-g portion of QY using sulfuric acid as the retainer and dodecylamine as the ligand (an ion-exchange reagent, 20% in the stationary phase), resulted in 1.21 g of 6′,5-diSA and 1.69 g of 6′,8′,5-triSA, both of over 99% purity. A minor component, 8′,4-diSA, not previously reported was also obtained (4.8 mg of over 94% purity) through a similar separation of a different batch of QY using hydrochloric acid as the retainer and 10% dodecylamine as the ligand in the stationary phase. Two components that co-eluted (0.55 g) in the 5 g separation were separated when trifluoroacetic acid was used as the retainer and tetrabutylammonium hydroxide (an ion-pair reagent) as the ligand. The separation resulted in 20.7 mg of 6′,4-diSA, not previously reported, and 111.8 mg of 8′,5-diSA, both of over 98% purity. The isolated compounds were characterized by high-resolution mass spectrometry and proton nuclear magnetic resonance with correlated spectroscopy assignments. 相似文献
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Guerino Mazzola 《manuscripta mathematica》1979,27(1):81-101
The scheme Alg5 of associative, unitary algebra structures on k5, k an algebraically closed field with char (k)2 is investigated. We establish the list of GL5-orbits on Alg5 under the action of structural transport. The numberalg5 of irreducible components of Alg5 is 10; a list of generic structures is included. We exhibit upper and lower bounds for the asymptotic behaviour of the numberalgn. 相似文献
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Letícia Caramori Cefali Daniele Cristina Barbosa de Oliveira Cristina Maria Franzini Janaína Artem Ataíde Patrícia Moriel Priscila Gava Mazzola 《Journal of Dispersion Science and Technology》2018,39(8):1149-1152
The aim of the present study was to carry out stability tests and in vitro sun protection factor (SPF) evaluations of formulations containing free or microencapsulated chemical sun filters to improve their use. To this end, three formulations were developed and subjected to stability studies. The most stable formulation was chosen as a vehicle for free and microencapsulated chemical sun filters, and subjected to further stability studies and in vitro SPF assays. The SPF values were approximately 12 and 11 for formulations containing free and encapsulated sun filters, respectively, and both types were stable under stress. Chemical sun filters can be microencapsulated, which may aid in generating innovative sunscreen formulations. 相似文献
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Chiappini Andrea Chiasera Alessandro Berneschi Simone Armellini Cristina Carpentiero Alessandro Mazzola Maurizio Moser Enrico Varas Stefano Righini Giancarlo C. Ferrari Maurizio 《Journal of Sol-Gel Science and Technology》2011,60(3):408-425
Sol–gel is a handy, very flexible, and cheap method to fabricate, study, and apply innovative photonic structures. The possibility
of starting from molecular precursors and elementary building blocks permits to tailor structures at the molecular level and
to create new materials with enhanced performances. Of specific interest for the study of important physical effects as well
as for application in light management are confined structures on the nano-micro scale as photonic crystal and planar waveguides.
Activation by luminescent species and in particular by rare earth ions allows results in the integrated optics area covering
application in sensing, biomedical diagnostic, telecommunication, lightning, and photon management. The present review is
focused on some recent results obtained by the authors in Sol–gel photonics. The first part presents colloidal structures
including single nano-micro spheres and photonic crystal structures. The second part of the review deals with amorphous and
transparent glass–ceramic employed for the fabrication of confined structures in planar format. Some specific application
are also reported to highlight the role of sol gel photonics in the development of high performance optical sensors, waveguide
lasers, and nanostructured materials. 相似文献
59.
Ackerman LK Noonan GO Begley TH Mazzola EP 《Rapid communications in mass spectrometry : RCM》2011,25(9):1336-1342
Two unknown compounds were previously determined to be potential interferences in liquid chromatography/tandem mass spectrometry (LC/MS/MS) analysis of bisphenol A (BPA) in canned infant formula. Both yielded two identical MS/MS transitions to BPA. The identities of the unknowns were investigated using accurate mass LC/MS, LC/MS/MS, and elemental formula and structures proposed. Exact identities were confirmed through purification or synthesis followed by (1)H and (13)C nuclear magnetic resonance (NMR) experiments, as well as comparisons of one unknown with commercial standards. Comparisons of negative ion electrospray ionization (ESI) MS/MS and accurate mass spectra suggested both unknowns to be structurally identical (to BPA and each other). Positive ion ESI spectra confirmed both were larger molecules, suggesting that in the negative mode they likely fragmented to the deprotonated BPA ion in the source [corrected]. Elemental composition of positive ion accurate mass spectra and NMR analysis concluded the unknowns were oxidized forms of the known epoxy can coating monomer, bisphenol A diglycidyl ether (BADGE). One of the unknowns, 2,2-[bis-4-(2,3-dihydroxypropoxy)phenyl]propane, commonly known as BADGE*2H(2)O, is widely reported as an epoxy-phenolic can coating migrant, but has not been suggested to interfere with the MS/MS analysis of BPA. The other unknown, 2-[4-(2,3-dihydroxypropoxy)phenyl]-2-[4'-hydroxyphenyl]propane, or the oxidized form of bisphenol A monoglycidyl ether (BAMGE*H(2)O), has not been previously reported in food or packaging. 相似文献