原子荧光光谱法测定土壤样品中痕量锌

土壤样品经硝酸-盐酸(3+1)溶液、氢氟酸和高氯酸消化处理后,在酸性条件下,以硼氢化钾为还原剂,用氢化物发生-原子荧光光谱法测定样品溶液中痕量锌的含量。锌的质量浓度在250μg.L-1以内与荧光强度呈线性关系,检出限(3s)为0.55μg.L-1。方法用于土壤样品分析,锌的测定值的相对标准偏差(n=11)在3.4%～6.3%之间,加标回收率在87.5%～102%之间。     

标准加入法在激光剥蚀电感耦合等离子体质谱测定粉末样品中的应用

采用固体混合制样方法研究了标准加入法在激光剥蚀电感耦合等离子体质谱(LA-ICP-MS)测定粉末样品中的应用.以汽车尾气催化剂中贵金属元素为研究对象,选择具有2,4-二巯基-1,3,5-三嗪官能团的硅胶(DMT)定量吸附不同含量的贵金属元素,与汽车尾气催化剂混合均匀后,制备成薄片,使用LA-ICP-MS方法测定各元素强...     

测定土壤中重金属元素的样品消解方法

探讨适用于重金属分析的土壤样品处理方法。利用原子吸收光谱法测定土壤中Cu,Mn,Ni,Pb和Zn 5种元素的含量,对电热板、微波和水浴3种消解方法进行比较,结果表明:3种样品预处理方法的检出限、准确度和精密度均满足分析检测要求。其中,电热板法样品消解较彻底,Cu和Pb的测定结果准确,但试剂、时间和人力消耗多,且为敞开式消解,高温及产生的大量酸雾危害环境与健康;微波法为密闭式消解,样品和试剂用量少,耗时短,自动化程度高,消解彻底,安全环保,Mn的测定结果准确,但成本高,不适于大批量样品分析;水浴法为半封闭式消解,简单易行,Ni和Zn的测定结果准确,但消解剂中不含氢氟酸,不适于含有大量硅酸盐样品的处理。     

粉末样品制备方法对扫描电子显微镜成像质量的影响

纳米粉末材料是化学化工领域常见的样品,在其扫描电子显微镜表征中,通常会遇到以下几个问题：二次电子产率低,粉末聚集结块从而导致无法观察纳米形貌,以及荷电效应等.以二氧化硅小球粉末、ZSM-5分子筛纳米片以及聚苯乙烯小球粉末为研究对象,在不镀金属膜的前提下,分别采用粉末直接涂抹在导电碳胶或银胶上和溶液分散后滴涂在不同基底上的方法进行样品制备,比较了直接涂抹和分散后滴涂在基底上两种方法对扫描电子显微镜成像的影响.结果表明,样品经过溶液分散能够有效的减小粉末的团聚,其中,滴涂在硅片基底上可以减小荷电效应和背景影响,清晰观察到粉末的纳米级形貌.     

土壤中总铬测定样品预处理方法的探讨

用GB／T 17137—1997中规定的两种方法即硝酸—氢氟酸—高氯酸—盐酸和硫酸—硝酸—氢氟酸—盐酸法对土壤样品进行消解；再用火焰原子吸收分光光度法测定其中铬的含量，两种样品消解方法测定结果之间存在显著性差异，后一种样品消解方法测定结果明显偏低。     

XPS分析固体粉末时的样品制备法研究

用XPS分析固体粉末样品时通常将粉末直接撒在双面胶带上进行测试.这种方法粉末容易脱落,并导致仪器污染或损坏.本文介绍一种将粉末样品铺在胶带上压成薄层进行测试的制样方法.后一种方法不需模具,简单快捷,实验表明它不仅有利于保护仪器,而且有利于提高XPS分析的灵敏度和分辨率.     

X射线荧光光谱法测定土壤和水系沉积物等样品中碳、氮、氟、氯、硫、溴等42种主次和痕量元素

采用粉末压片制样,用X射线荧光光谱法测定土壤、水系沉积物等样品中C、N、F、S、Cl、Br、Na、Mg、Al、Si、P、K、Ca、Ti、Mn、Fe、Co、Ni、Cu、Zn、Pb、Ga、As、Rb、Sr、Y、Zr、Nb、Th、U、Ba、La、Ce、Nd、Ge、Yb、W、Hf、Sc、Sn、Mo、Cs等42种元素。着重研究了C、N、F、S和Cl等元素的测量条件和存在问题;并研究了痕量元素的背景选择和谱线重叠校正的问题。方法的检出限,精密度和准确度绝大多数能满足覆盖区多目标地球化学调查样品的质量要求。     

粉末压片-X射线荧光光谱法测定富硅土壤和沉积物样品中的5种重金属元素

X射线荧光光谱法测定土壤和沉积物中的重金属具有简便、快速、准确等优点,但现有的环境行业标准方法不适用于SiO2含量大于80%的土壤和沉积物。为提高X射线荧光光谱法测定土壤和沉积物中的重金属在环境监测领域中的适用性,建立基于粉末压片-X射线荧光光谱法测定富硅土壤和沉积物中重金属的分析方法。通过选取富硅的土壤和沉积物标准物质提高校准曲线的测量范围以及优化各元素的测量条件,探讨基体效应和谱线重叠干扰、研究压片制样的最佳压力等途径,测定富硅土壤和沉积物中的Pb、Cr、Cu、Ni、Zn。结果表明在已优化的测定条件下,通过延长校准曲线的测量上限,保证待测元素含量在校准曲线范围内,同时采用经验系数法和康普顿散射内标法校正基体效应,可进一步提高方法的准确度和精密度。方法比对结果显示该方法的测定结果与原子吸收光谱法的测定结果无显著性差异。选用2种不同的富硅标准物质进一步验证方法的精密度和准确度,Pb、Cr、Cu、Ni、Zn的测定结果与标准物质认定值的对数误差为0.002~0.08,相对标准偏差为1.0%~4.6%。该方法的精密度和正确度满足土壤和水系沉积物环境监测分析的技术要求,具有良好的应用前景。     

Application of dried-droplets deposited on pre-cut filter paper disks for quantitative LA-ICP-MS imaging of biologically relevant minor and trace elements in tissue samples

In this work, a novel calibration approach for minor and trace element quantification in LA-ICP-MS imaging of biological tissues is presented. Droplets of aqueous standard solutions are deposited onto pre-cut pieces of filter paper, allowed to dry, and sputtered with a thin gold layer for use as pseudo-internal standard. Analysis of the standards using LA-ICP-MS is performed using radial line-scans across the filters. In contrast to conventionally used preparation of matrix-matched tissue standards, the dried-droplet approach offers a variety of advantages: The standards are easy to prepare, no characterization of the standards using acid digestion is required, no handling of biological materials is necessary, and the concentration range, as well the number of investigated analytes is almost unlimited. The proposed quantification method has been verified using homogenized tissue standards with known analyte concentrations before being applied to a human malignant mesothelioma biopsy from a patient who had not received any chemotherapeutic treatment. Elemental distribution images were acquired at a lateral resolution of 40 μm per pixel, limits of detection ranging from 0.1 μg g⁻¹ (Mn, Ni, Cu, Zn) to 13.2 μg g⁻¹ (K) were reached.     

铑靶康普顿散射校正XRF测定铝用碳素材料中的微量元素

通过对常用粘结剂中杂质元素含量的测定,选择硬脂酸做粘结剂,研磨压片制备样品,用X射线荧光光谱仪(XRF)测定铝用炭素阳极材料中硫、钒、钠、钙、硅、铁、镍、钛、铝、镁、磷、铅、锌、铬、锰含量的元素含量。通过实验确定了最佳的样品和粘结剂比例为12 g炭素试样加入2 g硬脂酸,研磨时间为20 s。测定铅元素时,选择一点法扣除背景,通过谱线强度数据确定使用PbLβ1做分析线。用铝用炭素阳极材料系列标准样品制作校准曲线,用铑靶康普顿散射内标校正铁、镍、铅、锌、铬、锰等元素,其余元素用经验系数法校正。样品精密度试验表明,样品中各元素测定结果的相对标准偏差(RSD,n=11)一般在8%以下,最高的钠元素和钛元素也在10%左右,未知样品的检测结果与标准结果没有显著性差异。     

Determination of trace elements in ambient aerosol samples

A microwave-assisted digestion procedure using HNO₃, HF, and H₂O₂ has been developed for analysis of elements in ambient particulate matter (PM). The samples are collected on cellulose filters and analyzed by inductively coupled plasma mass spectrometry (ICP-MS). The ICP-MS is calibrated with external standards, and recovery of analytes is tested with NIST SRM 1648 Urban Dust. This method has been used to quantify the airborne concentrations of a large number of elements, including Ag, As, Ba, Be, Ca, Cd, Ce, Co, Cr, Cs, Cu, Fe, Ga, K, Li, Mg, Mn, Mo, Ni, Pb, Rb, Se, Sb, Sr, Ti, Tl, V, and Zn. For the majority of these elements, recovery of the NIST SRM is within 15% of the certified values.     

高纯钛的辉光放电质谱法多元素分析

采用辉光放电质谱法(GD-MS)测定高纯钛中Mg、Al、Cr、Fe、V、Mn、Co、Ni、Cu、Zn、As、Sn、Sb、Ta、W、Pb、Bi等痕量杂质元素,并对GD-MS工作参数及条件进行了优化。主要元素与内标校正ICP-MS法定量分析的结果一致,对结果差异的原因进行分析,论述了Element GD辉光放电质谱仪在痕量杂质元素分析方面的优势。     

ICP-MS法测定高纯钛中痕量元素

建立了ICP-MS直接测定高纯钛中Be,V,Co,Ni,Ga,Mo,Nb,Cd,Sb,TI,Pb的分析方法,并对ICP-MS工作参数及条件进行了优化和选择.高纯钛用HF与HNO3溶解后加入Sc、Cs、Re内标,用ICP-MS直接检测.方法的检出限为0.03～0.1 ng/mL,测定下限为0.2～0.5 ng/mL,各元...     

Determination of trace elements in fly ash samples by FAAS after applying different digestion procedure

The fly ash samples obtained from Kangal Power Plant were prepared for FAAS analysis by a new approach. The trace elements of the fly ash samples were leached with appropriate solvents under suitable conditions. The leaching method is known as an effective technique for substances dissolving very hard and refractory materials. The leaching effects of solvents and their mixtures were investigated on fly ash samples that are used largely in analysis of soil and sediment samples.The fly ashes mainly consist of glassy aluminosilicates. The major components of the samples are SiO₂, Al₂O₃, CaO and Fe₂O₃. Therefore, decomposition of the silicate lattice of the fly ash is required for liberation of trace elements. The dissolution process can be completed by using a mineral acid such as concentrated HCl. This technique has an advantage that the fly ash can be dissolved without any oxidation at room temperature.Maximum element recoveries were obtained by the procedure of 37% HCl leaching after the samples were treated with 2.0 ml of concentrated HF. It was also observed that maximum mass loss occurred in this procedure. The effect of the four leaching reagents, which are HCl, HNO₃, HClO₄ and HNO₃ + HClO_4, were investigated on fly ash samples that were treated with concentrated HF. An optimum leaching method was determined based on the confidence of analytical results and element recovery rates.     

GD-MS法和ICP-MS法测定高纯铌中痕量元素

采用辉光放电质谱法(GD-MS)对高纯铌中Ta,Mo,W等痕量杂质元素进行了测试,并对GD-MS工作参数进行了优化,部分元素与采用电感耦合等离子体质谱法(ICP-MS)定量分析的结果进行比较,对某些元素含量差别较大的原因进行了分析,论述了Element GD辉光放电质谱仪的特点及其在痕量杂质分析上的优势。     

彭泽贝母中微量元素的测定及初级形态分析

采用HNO3-H2O2微波消解体系,电感耦合等离子质谱法(ICP-MS)测定彭泽贝母中Pb、Ca、Fe、Mn、Zn、Cd、Ba、Cr等10种微量元素,初步探究微量元素的存在形态.结果表明:彭泽贝母中含有丰富的人体必需微量元素,可能促进其有效成分作用的发挥.其中Ca在彭泽贝母中含量最高,而Mo含量最低;彭泽贝母中微量元素是以无机态为主、多种形态共存的复杂体系.     

离子色谱-膜去溶-ICP-MS法测定高纯钨粉中痕量金属杂质

灵敏地检测了高纯钨粉中的痕量金属杂质.钨粉用H2O2溶解后进入离子色谱的阳离子交换柱,经水淋洗后,用HNO3洗脱,洗脱后的溶液经过膜去溶装置雾化去溶后进入电感耦合等离子体质谱检测.除B,V,Sb外,其它杂质元素如Mg,Al,Ti,Cr,Be,Fe,Mn,Co,Ni,Cu,Zn,Ga,Sr,Cd,Ba等的回收率均在90%～107%之间,检出限在0.001～0.5μg/g之间.