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Elżbieta Lipiec Grzegorz Siara Katarzyna Bierla Laurent Ouerdane Joanna Szpunar 《Analytical and bioanalytical chemistry》2010,397(2):731-741
A method for the simultaneous determination of selenomethionine (SeMet), selenocysteine (SeCys), and selenite [Se(IV)] in
chicken eggs was developed. A sample preparation protocol including defatting, protein denaturation, and carbamidomethylation
was optimized in order to achieve complete protein digestion and to avoid SeCys losses. Quantification was carried out by
reversed-phase HPLC–inductively coupled plasma mass spectrometry (ICP MS) after quantitative isolation of the selenium-containing
fraction by size-exclusion liquid chromatography. The detection limits were 0.06, 0.003, and 0.01 μg g−1 (dry weight) for SeCys, Se(IV) and SeMet, respectively, and the precision was 5–10%. The end products of carbamidomethylation
of the different selenium species were identified for the first time by electrospray QTOF MS after custom-designed 2D HPLC
purification. Differences in selenium speciation in egg yolk and white were highlighted, the yolk containing more SeCys and
the white more SeMet. An insight into selenium bioaccessibility in eggs was obtained by digestion with simulated gastric and
gastrointestinal juices and size-exclusion HPLC-ICP MS. 相似文献
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Joseane Sarmento Lazarotto Vitória de Lima Brombilla Siara Silvestri Edson Luiz Foletto 《应用有机金属化学》2020,34(12):e6001
A novel composite, biochar derived from spent coffee grounds with immobilized TiO2 (biochar–TiO2) was prepared, characterized, and applied as an alternative, effective, and sustainable photocatalyst for degrading diclofenac from aqueous solution. Composites with different mass ratios between TiO2 and biochar were prepared by mechanical mixing and subsequent pyrolysis in an inert atmosphere of N2 at 650°C. The sample with biochar–TiO2 ratio of 1:1 presented a degradation efficiency of 90% at just 120 min versus 40% for TiO2 used as reference. This fact is associated with a set of intrinsic characteristics obtained during the formation of the composite, such as superior pore size, avoiding the recombination of the ē/h+ pair, bandgap reduction, and promotion of reactive oxygen species due to phenolic groups present on the biochar surface. The dominant reactive species involved during the photocatalytic degradation of diclofenac were h+ and •OH. The diclofenac degradation pathways were determined based on the identification of intermediates and nonpurgeable organic carbon (NPOC) analysis. The novel biochar–TiO2 composite prepared in this work showed high physical–chemical stability and efficiency over five consecutive cycles of reuse, proving to be a highly promising photocatalyst for degrading diclofenac in water. 相似文献
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Silvestri Siara Stefanello Nádia da Silveira Salla Julia Foletto Edson Luiz 《Research on Chemical Intermediates》2019,45(9):4299-4313
Research on Chemical Intermediates - In this work, different synthesis methods of zinc stannate (Zn2SnO4–ZTO) were proposed in order to obtain a material with a... 相似文献
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