Determination of Mineral Elements in Milk Products by Inductively Coupled Plasma-Optical Emission Spectrometry

The determination of mineral elements in milk products is of great importance since their excess or deficiency may affect human health. In this study, calcium, magnesium, potassium, sodium, phosphorus, and iron were determined in milk products from South Korea. The samples were wet-digested by microwave-assisted combustion using nitric acid and hydrogen peroxide, and analyzed by inductively coupled plasma-optical emission spectrometry. The method was validated by sensitivity, linearity, precision, recovery checks, and the analysis of a milk powder certified reference material. The elemental concentrations were similar in the milk products. Calcium and potassium were the most abundant, followed by phosphorus, sodium, magnesium, and iron. All concentrations were comparable to previous values and were within the limits of recommended dietary allowances and tolerable upper levels.     

断续流动氢化物发生原子荧光法测定饮用矿泉水中硒

介绍断续流动氢化物发生原子荧光测定饮用矿泉水中硒的方法， 研究了酸度、硼氢化钾浓度、灯电流、载气流速等对测定硒的影响，找出最佳测定饮用矿泉水中硒的条件。方法具有操作简便、快速、灵敏度高等优点。     

黄龙山天然矿泉水临床应用观察

观察了黄龙山天然矿泉水系统治疗多种常见慢性病,如：消化功能紊乱,小儿厌食症,高血压病,神经衰弱、皮肤病等的效果,总有效率达92．58%,其原因是该矿泉水富含人体必需微量元素。     

银离子固相萃取-程序升温大体积进样-气相色谱法定量分析市售巧克力中的饱和烷烃矿物油

建立了银渍硅胶固相萃取柱离线(Ag-SPE)净化,程序升温进样-气相色谱-氢火焰离子化检测器(PTV-GC-FID)定量分析巧克力中饱和烷烃矿物油(MOSH)的方法.以正己烷浸泡提取巧克力中的MOSH,离心后取1 mL上清液,过0.3％ Ag渍硅胶SPE柱净化,氮吹浓缩,定容至0.2 mL,注入GC分析; GC的进样口程序升温过程:初始温度45℃,保持1 min(分流比200∶1),以250℃/min升温至360℃(分流阀关闭2 min),并保持27 min(分流比100∶1); 进样量40 μL; 柱温箱升温程序为:35℃保持3 min,以25℃/min升温至350℃,以5℃/min升温至370℃,保持10 min,载气为高纯氮气,流速1.3 mL/min(压力60 kPa); FID温度为380℃.结果表明,本方法的MOSH定量限为0.5 mg/kg,加标回收率为84.9％～108.6％,相对标准偏差(RSD)为0.2％～1.5％.运用本方法对25个市售巧克力样品中的MOSH含量进行了测定,3个样品未检出,其余22个样品中MOSH含量为1.09～8.15 mg/kg(其中C16～C35 的含量为0.56～4.43 mg/kg),有3个样品含量高于5.00 mg/kg,为严重污染样品.本方法操作简便,检出限低,适用于巧克力中MOSH的定量测定.     

矿物分析技术及进展

评述了2001年11月至2003年10月期间国内有关矿物分析技术的现状及进展概况。内容包括综述与会议、重量法与滴定法、光度法、电化学分析法、原子光谱分析法、X射线荧光光谱法、电感耦合等离子体质谱法、联用技术、国家标准方法及其它。     

Stokes flow through microstructural model of fibrous media

Viscous flow through a two-dimensional model of fibrous media is analyzed. The periodic model is based on array of cylindrical fibres on a triangular lattice. The numerical approach consists in satisfying boundary conditions by using a least squares method applied to the analytical solution of Stokes motion around a cylinder. Our interest is in the drag force exerted on the array, and hence the permeability of such arrays. Results are given over the full porosity range. Furthermore, the flow structure analysis is carried out as a function of porosity. For low porosity values, recirculation motion composed of Stokes eddies are obtained that play an important role in pollution phenomena.     

Coupling of imaging NEXAFS with secondary ion mass spectrometry for the chemical and isotopic analysis of presolar cosmic grains

We present first results of the combination of imaging photoemission electron spectroscopy with imaging mass spectrometry. Imaging NEXAFS was combined with TOF-SIMS in order to perform a spatially resolved chemical and isotopic analysis of microscopic grain samples. Imaging NEXAFS was used for the nondestructive lateral characterization of mineral phases prior to isotopically resolved mass analysis by imaging TOF-SIMS. This novel approach was demonstrated by performing a chemical and isotopic analysis of the rare presolar grain fraction present in the Murchison meteorite.     

改进的堆栈稀疏自编码矿物高光谱端元识别研究

自然界中岩石一般是由多种矿物集合而成的紧致混合物,由于高光谱传感器低空间分辨率的特征,获得的高光谱数据多为矿物组分的综合反映.受噪声干扰以及矿物复杂的混合机理等因素影响,高光谱端元识别和定量分析成为目前研究的热点与难点.基于深度学习理论,对原始自编码结构进行改进,提出了一种改进的堆栈稀疏自编码的矿物高光谱端元识别方法(...     

改性钢渣-矿粉复合橡胶填料补强-阻燃机理的光谱学分析

钢渣作为炼钢过程中产生的固体废弃物,矿渣作为高炉炼铁过程中的副产品,其存在难以利用与附加值的问题.面对上述问题,利用钢渣与矿渣开发一种价格低廉的复合橡胶填料用于橡胶领域.采用磁选热闷渣、未磁选热闷渣、矿粉和助磨-改性复合剂制备改性钢渣-矿粉复合橡胶填料,并且用于复合橡胶体系.研究磁选热闷渣用量、未磁选热闷渣用量、矿粉用...