Facile Synthesis of the Magnetic Metal Organic Framework Fe3O4@UiO-66-NH2 for Separation of Strontium.

A magnetic metal organic framework (MMOF) was synthesized and used to separate Sr2+ in aqueous solution. The shape and structure of prepared Fe3O4@UiO-66-NH2 were characterized, and the absorbed concentration of strontium was determined through inductively coupled plasma mass spectrometry. The results indicated that Fe3O4 and UiO-66-NH2 combined through chemical bonding. The experimental adsorption results for separation of Sr2+ in aqueous solution indicated that the adsorption of Sr2+ to Fe3O4@UiO-66-NH2 increased drastically from pH 11 to pH 13. The adsorption isotherm model indicated that the adsorption of Sr2+ conformed to the Freundlich isotherm model (R2 = 0.9919). The MMOF thus inherited the superior qualities of magnetic composites and metal organic frameworks, and can easily be separated under an external magnetic field. This MMOF thus has potential applications as a magnetic adsorbent for low level radionuclide 90Sr.

Determination of Trace Elements in Edible Nuts in the Beijing Market by ICP-M.

Nuts have received increased attention from the public in recent years as important sources of some essential elements, and information on the levels of elements in edible nuts is useful to consumers. Determination of the elemental distributions in nuts is not only necessary in evaluating the total dietary intake of the essential elements, but also useful in detecting heavy metal contamination in food. The aim of this study was to determine the mineral contents in edible nuts, and to assess the food safety of nuts in the Beijing market. Levels of Li, Cr, Mn, Co, Cu, Zn, As, Se, Rb, Sr, Mo, Cd, Cs, Ba, Pb, Th, and U in 11 types of edible nuts and seeds (macadamia nuts, lotus nuts, pistachios, sunflower seeds, pine nuts, almonds, walnuts, chestnuts, hazelnuts, cashews, and ginkgo nuts) as well as raisins were determined by inductively coupled plasma mass spectrometry (ICP-MS). The accuracy of the method was validated using standard reference materials GBW10014 (cabbage) and GBW10016 (tea). Our results provide useful information for evaluating the levels of trace elements in edible nuts in the Beijing market, will be helpful for improving food safety, and will aid in better protecting consumer interests.

Determination of total tritium in urine from residents living in the vicinity of nuclear power plants in Qinshan, China.

To estimate the tritium doses of the residents living in the vicinity of a nuclear power plant, urine samples of 34 adults were collected from residents living near the Qinshan nuclear power plant. The tritium-in-urine (HTO plus OBT) was measured by liquid scintillation counting. The doses of tritium-in-urine from participants living at 2, 10 and 22 km were in a range of 1.26-6.73 Bq/L, 1.31-3.09 Bq/L and 2.21-3.81 Bq/L, respectively, while the average activity concentrations of participants from the three groups were 3.53 ± 1.62, 2.09 ± 0.62 and 2.97 ± 0.78 Bq/L, respectively. The personal committed effective doses for males were 2.5 ± 1.7 nSv and for females they were 2.9 ± 1.3 nSv. These results indicate that tritium concentrations in urine samples from residents living at 2 km from a nuclear power plant are significantly higher than those at 10 km. It may be the downwind direction that caused a higher dose in participants living at 22 km. All the measured doses of tritium-in-urine are in a background level range.

Determination of the metals by ICP-MS in wild mushrooms from Yunnan, China.

UNLABELLED: The elemental contents of Li, Cs, U, Co, As, Sr, Cd, Ba, Pb, Sb in 157 wild-grown mushrooms were determined by inductively coupled plasma mass spectrometry (ICP-MS). The mushrooms including 9 species were collected from 5 counties in Yunnan province, China. Based on the findings for the results from the certified reference materials GBW10014 (cabbage) and GBW10016 (tea), the data from the sample mushrooms were corrected. The contents of investigated trace elements in mushroom samples were determined as µg/g dry weight (dw) in the range of 0.030 to 13 for Li, 0.070 to 8.1 for Cs, 0.0010 to 0.28 for U, 0.040 to 5.4 for Co, 0.070 to 44 for As, 0.28 to 86 for Sr, and 0.15 to 23 for Cd. The maximum contents were 58, 11, and 0.11 for Ba, Pb, and Sb, respectively. The minimum contents of Ba, Pb, and Sb were below the detection limit of the method used. PRACTICAL APPLICATION: The analysis of 9 species wild-grown edible mushrooms in different regions provides the useful information to evaluate the levels of elements or of the toxic heavy metals, such as Cd, As in wild-grown edible mushrooms which grew in different regions of China for consumers and other interested groups, especially for the regulators.