Fractionation and Bioaccessibility of Manganese,Copper, Zinc,Cadmium, and Lead in Commercial Vegetable and Rice Baby Foods Using Inductively Coupled Plasma - Mass Spectrometry (ICP-MS) with Central Composite Design (CCD)

Abstract

Herein the bioaccessibility of Mn, Cu, Zn, Cd, and Pb, selected from essential and toxic elements, was determined in commercially sold vegetable purees intended for infant and toddler consumption. Chemical fractionation studies using water, acetone, diethyl ether, chloroform:methanol, and n-hexane were employed to predict the importance of the protein and lipid parts of a matrix to assess the bioaccessibility data. In addition, in-vitro gastrointestinal digestion was performed to determine the bioaccessibility of the elements using a five level, three factor central composite design (CCD) to maximize the elemental solubility. The total elemental concentrations in all of the fractions were determined by inductively coupled plasma – mass spectrometry (ICP-MS). Based on the consumption of one jar of vegetable/rice-based baby food, Zn was 1.3% of the recommended dietary allowance and Mn was 4.2% of the adequate intake level, while Cu was almost 100% of the adequate intake level. Additionally, Pb was always below the detection limit and Cd was sometimes under the detection limit for the percent bioaccessibility. However, in some samples, Cd was as high as 80% of the tolerable weekly intake level depending on the body weight.     

Zur Kenntnis der Hydrate M(HSeO3)2 · 4H2O (M = Mg,Co, Ni,Zn). Röntgenstrukturanalytische,schwingungsspektroskopische und thermoanalytische Untersuchungen

On the Hydrates M(HSeO₃)₂ · 4H₂O (M = Mg, Co, Ni, Zn) – Crystal Structures, IR, Raman, and Thermoanalytical Investigations From aqueous solutions of M(HSeO₃)₂ single crystals of Mg(HSeO₃)₂ · 4H₂O and of the hitherto unknown compounds Co(HSeO₃)₂ · 4H₂O, Ni(HSeO₃)₂ · 4H₂O and Zn(HSeO₃)₂ · 4H₂O could be obtained. The crystal structures, X-ray powder, IR, Raman and thermoanalytical (DTA, TG, Raman heating) data are presented and discussed. The crystal data of the isotypic compounds are: monoclinic, space group C2/c, Z = 4, Mg: a = 1 464.6(2), b = 755.3(1), c = 1 099.9(1) pm, β = 126.59(1)°, V = 0.9769(1) nm³, Co: a = 1 462.5(2), b = 756.5(2), c = 1 102.2(2) pm, β = 126.53(1)°, V = 0.9798(2) nm³, Ni: a = 1 452.2(2), b = 751.0(1), c = 1 091.5(1) pm, β = 126.28(1)°, V = 0.9595(1) nm³, Zn: a = 1 468.3(2), b = 755.8(1), c = 1 103.1(1) pm, β = 126.79(1)°, V = 0.9804(2) nm³. The crystal structures consist of hexagonal packed [M(HSeO₃)₂ · 2H₂O]_n chains of [MO₄(H₂O)₂] octahedra linked by Se atoms. They contain trigonal pyramidal SeO₂OH^?ions with “free” hydroxyl groups and also “free” molecules of water of crystallization. The hydroxyl groups build strong H-bonds (O? H …? O distances: 265–268 pm). The IR spectra show AB doublett bands in the OH stretching mode region of the hydroxyl groups. The water molecules of crystallization are linked to planar (H₂O)₄ tetramers by H-bonds with unusually short O? H …? O bond distances of 271–273 pm. DTA and TG measurements indicate that thermal decomposition results in the direct formation of the respective diselenite MSe₂O₅. Raman heating measurements show under quasi static conditions the intermediate formation of the anhydrous hydrogen selenites.     

Schrödinger Equation Solutions for the Central Field Power Potential Energy I. V(r) = V 0(r/a 0)2ν−2, ν ≥ 1

The solution of a generalized non-relativistic Schrödinger equation with radial potential energy V(r)=V ₀(r/a ₀)^2–2 is presented. After reviewing the general properties of the radial ordinary differential equation, power series solutions are developed. The Green's function is constructed, its trace and the trace of its first iteration are calculated, and the ability of the traces to provide upper and lower bounds for the ground eigenvalue is examined. In addition, WKB-like solutions for the eigenvalues and eigenfunctions are derived. The approximation method yields valid eigenvalues for large quantum numbers (Rydberg states).     

Pyrolysis and TG Analysis of Shivee Ovoo Coal from Mongolia

The coal sample of the Shivee Ovoo deposits has been non-isothermally pyrolysed in a thermogravimetric analyser to determine the influence of temperature, heating rate and purge gas employed on the thermal degradation of the sample. The heating rates investigated in the TG were 10–50 K min^–1 to final temperature of 1000°C. N₂or CO₂ were employed as well as type of purge gas on the process of thermal degradation of the coal sample. The coal was also investigated in a fixed bed reactor to determine the influence of temperature and heating rate of the pyrolysis on the yield of products and composition of the gases evolved. The main gases produced were H₂, CH₄, C₂H₂, C₂H₄, C₂H₆, C₃H₆ and C₃H₈ and also minor concentrations of other gases. This revised version was published online in August 2006 with corrections to the Cover Date.     

Thermal behaviour and slow molecular mobility in two isomers of biphenylmethanol

This research was aimed to investigate the role of clay on the combustion and kinetic behavior of crude oils in limestone matrix. For this purpose, simultaneous TG (thermogravimetry) and DTA (differential thermal analysis) experiments were performed at three different heating rates as 10–15 and 20°C min^–1, respectively. A uniform trend of decreasing activation energies was observed with the addition of clay. It was concluded that clays surface area affects the values of Arrhenius constant, while it is the catalytic properties of clay, which lower the activation energies of all the reactions, involved in the combustion process.     

Ternary and tetrahedral symmetry in hybrid fluorides, fluoride carbonates and carbonates

Tren amine cations and carbonate anions adopt a ternary symmetry while tetra amine cations are tetrahedral. The symmetry of these constitutive ions influences strongly the nature of the solids which crystallise from solutions. Large fluorinated aluminate polyanions with tetrahedral symmetry appear in the presence of tren amine, while infinite chains of AlF₆ octahedra are observed with tetra amine and that noncentrosymmetric structures are frequently encountered in rare earth fluoride carbonates.     

Calibration of a quenching and deformation differential dilatometer upon heating and cooling: Thermal expansion of Fe and Fe-Ni alloys

Dilatometry is a technique for precise measurement of thermal dilatation of materials during heating or cooling. A procedure has been presented for calibration of a differential dilatometer operating with electromagnetic heating for metallic specimens both upon heating and cooling as well as under uniaxial compressive and tensile loading. The dilation signal has been calibrated for both heating and cooling and for uniaxial loading (compressive and tensile) using platinum or iron reference specimens, for which recommended dilational data are available. The ferro- to paramagnetic transition (characterised by the Curie temperature) of pure iron or iron-based alloys has been adopted to calibrate the temperature in the dilatometric measurement under different loading modes during heating and cooling. On this basis calibrated data for the thermal expansion coefficients of Fe and Fe-Ni alloys have been obtained.     

Estimation of a quantile in some nonstandard cases

A necessary condition for the asymptotic normality of the sample quantile estimator isf(Q(p))=F(Q(p))>0, whereQ(p) is thep-th quantile of the distribution functionF(x). In this paper, we estimate a quantile by a kernel quantile estimator when this condition is violated. We have shown that the kernel quantile estimator is asymptotically normal in some nonstandard cases. The optimal convergence rate of the mean squared error for the kernel estimator is obtained with respect to the asymptotically optimal bandwidth. A law of the iterated logarithm is also established.This research was partially supported by the new faculty award from the University of Oregon.     

Convolution semigroups and central limit theorem associated with a dual convolution structure

We consider hypergroups associated with Jacobi functions ⁽⁾ (x), (–1/2). We prove the existence of a dual convolution structure on [0,+[i(]0,s ₀]{{) =++1,s ₀=min(,–+1). Next we establish a Lévy-Khintchine type formula which permits to characterize the semigroup and the infinitely divisible probabilities associated with this dual convolution, finally we prove a central limit theorem.     

微波辐射下无催化剂一锅法合成N-甲基十氢吖啶-1,8-二酮化合物

为了研究从简单易得的原料在无催化剂的条件下一锅法合成N-甲基十氢吖啶-1,8-二酮化合物，我们以各类醛（脂肪醛、芳香醛、二醛）、达咪酮或1,3-环己二酮和甲胺为原料，以乙二醇或水为溶剂，经微波辐射，一步反应得到了一系列N-甲基十氢吖啶-1,8-二酮化合物。反应时间从传统热反应的4-5小时缩短至2-10分钟，产率较高（56-95%），并且不需要使用催化剂。该反应后处理方便，只需要简单洗涤，环境友好，为合成此类化合物提供了一种简便、有效的合成方法。该方法不仅适用于一元脂肪醛、芳香醛，还适用于芳香二醛，因此可以合成含有一个或两个十氢吖啶结构单元的杂环化合物。