Synthesis of a UiO-66/g-C3N4 composite using terephthalic acid obtained from waste plastic for the photocatalytic degradation of the chemical warfare agent simulant, methyl paraoxon.

In our study, Zr-based UiO-66 (Zr) was synthesized using terephthalic acid obtained from waste plastic. Thereafter, UiO-66/g-C3N4 composites were prepared by the solvothermal method, and their photocatalytic activity in the photodegradation of the chemical warfare agent simulant, dimethyl 4-nitrophenyl phosphate (DMNP), was evaluated. The as-synthesized UiO-66/g-C3N4 exhibited a high surface area (1440 m2 g-1) and a high capillary volume (1.49 cm3 g-1). The UiO-66/g-C3N4 samples absorbed a visible light band with bandgap energies of 2.13-2.88 eV. The as-synthesized UiO-66/g-C3N4 composites exhibited highly efficient degradation of DMNP with a short half-life (t 1/2 of 2.17 min) at pH 7 under visible light irradiation. The trapping experiments confirmed that the h+ and ˙O2 - radicals played an important role in the photocatalytic degradation of DMNP. The UiO-66/g-C3N4 catalyst simultaneously performed two processes: the hydrolysis and photocatalytic oxidation of DMNP in water. During irradiation, a p-n heterojunction between UiO-66 and g-C3N4 restricted the recombination of photogenerated electrons and holes, resulting in the enhancement in the degradation rate of DMNP.

Immobilization of D-Amino Acid Oxidase (DAAO) Enzyme on Hybrid Mesoporous MCF, SBA-15 and MCM-41 Nanomaterial.

Hybrid mesoporous materials as carriers for immobilization of D-amino acid oxidase (DAAO) were prepared via three steps: (i) hydrothermal synthesis of nanoporous MCF, SBA-15 and MCM-41 powders, (ii) functionalization with 3-aminopropyltriethoxysilane (APTES) by post-synthesis grafting; and (iii) activation with glutardialdehyde. The resulting mesostructured solids were characterized by various techniques: XRD, IR, TGA-DTA and N2 adsorption­desorption (BET). The characterization results indicated that these materials still maintained their structure after functionalization. IR data and TGA-DTA analysis demonstrated the existence of amine functional groups on the surface of APTES-functionalized samples. The DAAO immobilized on these materials exhibited higher catalytic activity and stability of enzyme for conversion of cephalosporin C (CPC) as compared to those of the non-functionalized ones. The catalytic activity and stability of enzyme decreased in the order MCF > SBA-15 > MCM-41.

Analytical ingredient content and variability of adult multivitamin/mineral products: national estimates for the Dietary Supplement Ingredient Database.

BACKGROUND: Multivitamin/mineral products (MVMs) are the dietary supplements most commonly used by US adults. During manufacturing, some ingredients are added in amounts exceeding the label claims to compensate for expected losses during the shelf life. Establishing the health benefits and harms of MVMs requires accurate estimates of nutrient intake from MVMs based on measures of actual rather than labeled ingredient amounts. OBJECTIVES: Our goals were to determine relations between analytically measured and labeled ingredient content and to compare adult MVM composition with Recommended Dietary Allowances (RDAs) and Tolerable Upper Intake Levels. DESIGN: Adult MVMs were purchased while following a national sampling plan and chemically analyzed for vitamin and mineral content with certified reference materials in qualified laboratories. For each ingredient, predicted mean percentage differences between analytically obtained and labeled amounts were calculated with the use of regression equations. RESULTS: For 12 of 18 nutrients, most products had labeled amounts at or above RDAs. The mean measured content of all ingredients (except thiamin) exceeded labeled amounts (overages). Predicted mean percentage differences exceeded labeled amounts by 1.5-13% for copper, manganese, magnesium, niacin, phosphorus, potassium, folic acid, riboflavin, and vitamins B-12, C, and E, and by ∼25% for selenium and iodine, regardless of labeled amount. In contrast, thiamin, vitamin B-6, calcium, iron, and zinc had linear or quadratic relations between the labeled and percentage differences, with ranges from -6.5% to 8.6%, -3.5% to 21%, 7.1% to 29.3%, -0.5% to 16.4%, and -1.9% to 8.1%, respectively. Analytically adjusted ingredient amounts are linked to adult MVMs reported in the NHANES 2003-2008 via the Dietary Supplement Ingredient Database (http://dsid.usda.nih.gov) to facilitate more accurate intake quantification. CONCLUSIONS: Vitamin and mineral overages were measured in adult MVMs, most of which already meet RDAs. Therefore, nutrient overexposures from supplements combined with typical food intake may have unintended health consequences, although this would require further examination.