沉积物中~(129)I不同形态的逐级浸取分离

随着核技术的不断发展,核试验、乏燃料后处理及核电站事故等人类核活动向自然界释放了大量的~(129)I。~(129)I在沉积物中的含量与化学形态分布对揭示其迁移规律和沉降信息有着重要的意义。因此,对于研究沉积物中~(129)I不同形态所需要的合理分离及制备流程就尤为重要。结合太湖湖泊沉积物的特点并通过比较众多沉积物中~(129)I形态的分离流程,提出了改进的逐级浸取流程。在温度、时间不同的实验条件下,对沉积物样品分离出沉积物中~(129)I可交换态、有机结合态、金属氧化物态、残余矿物态四种不同形态,并通过高温热解法及125I示踪计算回收率及损失率。改进后的逐级浸取法能达到90%的提取效率,离子可交换态、有机结合态、金属氧化物结合态的适宜浸取时间和温度分别为4.5h、30℃,4.5h、75℃,5.5h、75℃。流程适用于同类湖底沉积物样品分析。     

沉积物中重金属形态分析方法研究进展

介绍近年来国内外对沉积物中重金属的研究概况,以及重金属形态分离方法和监测方法的最新进展,对国内外常用的沉积物中重金属的形态分析提取方法如Tessier法、Forstner法和BCR法进行了比较,概述了重金属形态分离检测方法。     

象山港海底沉积物中重金属的赋存形态

以象山港海底沉积物为研究对象,采用了五步连续萃取法对象山港区域表层沉积物中重金属(Fe、Mn、Cu、Zn)赋存形态进行了研究,分析了各形态重金属在象山港不同采样点中的分布特征和影响因素.结果表明,象山港海域表层沉积物中各重金属元素主要来源于自然输入的残留态,人为输入的各种活性形态所占比例相对较少,但受两种因素的影响的差...     

水体沉积物中汞形态分析方法进展

文中对近年来汞的形态分析的发展作了评述.主要涉及色谱法、原子吸收光谱法、原子荧光光谱法、电化学分析法、中子活化法及毛细管电泳法在汞形态分析中的应用(引述文献32篇).     

沉积物样品中痕量元素汞的形态分析研究进展

归纳总结了沉积物中汞形态分析研究进展,内容包括沉积物汞的赋存形态,样品的预处理和不同形态汞的原子光谱法、色谱法、电感耦合等离子体质谱法及联用技术等分析方法,指出了存在的问题和未来的发展方向。     

硝酸、硫化钠溶液浸取冷原子荧光法选择性测定土壤及河流沉积物中硫化汞

本文研究了饱和硫化钠溶液对土壤样品中硫化汞的浸取效率(其加标回收率达100%),以及用硝酸和硫化钠溶液对样品中汞的选择性浸取并研究了土壤中硫化汞垂直分布。提出了利用硝酸、饱和硫化钠溶液浸取,由冷原子荧光法选择性测定土壤及河流沉积物中硫化汞的新方法。用该方法对同一样品进行8次测定,其相对标准偏差为7.1%。     

两步酸化DPASV对乐安江沉积物水提液中铜的毒性形态分析

本文采用两步酸化分脉冲阳极溶出伏安法（ＤＡＭ－ＤＰＡＳＶ）对乐安江沉积物水提液中的铜进行形态分析，并与直接ＤＰＡＳＶ测试及生物测试（Ｄ，ｍａｇｎａ）结果进行了比较，结果表明，直接ＤＰＡＳＶ测试因水体中络合剂和表面活性剂的干扰而低估了毒性形态，而两步酸化ＤＰＡＳＶ较好地反映出了铜的毒性形态。     

连续萃取法研究海湾养殖区沉积物中重金属形态

以连续萃取法研究海湾养殖区沉积物中重金属(Cd, Cu, Pb, Zn)的形态,将重金属分离为酸溶态、还原态、有机质结合态、硫化物结合态和残渣态.分别采用基体匹配法和内标法消除高盐基体对电感耦合等离子体光谱法(ICP-OES)和质谱法(ICP-MS)分析结果的影响.对海洋沉积物标准物质分析结果表明,样品稀释后测定值与标准值一致.比较了本连续萃取法和BCR法对沉积物样品中重金属形态的提取结果,并考察了萃取剂的选择性.实验表明,本方法可用于有机质污染和富营养化环境沉积物中重金属形态分析,特别是有机质结合态和硫化物结合态的分析.     

FIA-ICP/AES法分析茶叶浸取液中多元素的形态

本文报道了分析茶叶浸取液中[Zn、Mn、Fe、Al及Mg]形态的新方法。研究了以C-18柱为分离柱的流动注射与ICP/AES的联用技术。     

加速器质谱法测定环境和生物样品中的129I

建立了环境和生物样品中的129I的分析方法,采用碱式灰化、萃取-反萃、沉淀等步骤对环境和生物样品中的碘进行预浓集,用131I[NaI] 为放射性示踪剂优化各分步的制备条件,运用加速器质谱法测定了北京地区松针和干草、青岛地区海藻和海水中的129I/127I.用超热中子活化法测定样品中的稳定碘(即127I)含量.上述松针、干草、海藻和海水样品中的129I/127I分别为8.11×10-9、5.97×10-9、1.70×10-10和6.05×10-10;相应的129I浓度分别为3.22×10-15、1.24×10-14、1.27×10-14 g/g干重和2.30×10-14 g/L.与文献报道值相比,我国与国外同类地区相当甚至更低,比法国和英国乏核燃料后处理厂附近环境中的129I低2～3个数量级,表明我国这些非核设施影响地区的129I处于当今全球环境的本底放射性沉降水平.     

Continuous Ultrasound-Assisted Leaching of Phenoxyacid Herbicides in Soil and Sediment with in-situ Sample Treatment

Summary Ultrasound, water and Na₂EDTA·2H₂O have been used for continuous leaching with in-situ sample treatment of acid herbicides (namely, bentazone, 2,4-D, trichlopyr, 2,4,5-T and 2,4,5-Tp) from different types of soil (namely, clayey, slimy, sandy, organic and limy) and one sediment. The subsequent steps for quantitation of the leached analytes (namely, preconcentration, individual chromatographic separation and UV detection) were performed using a flow injection manifold that permits automation of the overall process. The main factors contributing to the leaching efficiency—namely, ultrasound radiation amplitude, probe position, percentage of duty cycle of ultrasound exposure, extractant flow-rate and temperature of the water bath in which the extraction cell is immersed—were optimized by means of a central composite design. Also, the kinetics of the leaching step with Na₂EDTA·2H₂O was studied. In all cases, the recoveries of the target analytes were higher than 92%. The detection and quantification limits were 10 and 30 ng g^–1, respectively, for all analytes, but trichlopyr (detection and quantification limits 5 and 12 ng g^–1, respectively). The relative standard deviations for repeatability range between 2.8–5.3%.     

129I levels in soils from Ukraine and Slovenia in the last decade

¹²⁹I is important as an environmental tracer of the biogeochemical cycling of iodine and of the dissemination of nuclear pollution, because anthropogenic ¹²⁹I has been released from only few point sources and with its short mixing time its distribution therefore reveals the movement of ¹²⁹I in the environment. A radiochemical neutron activation analysis method was developed to measure the concentration of ¹²⁹I in soil samples. A procedure to pre-concentrate iodine from up to 150?g of soil was developed and validated using IAEA standard reference material IAEA-375 (Chernobyl soil). The method was applied to determine ¹²⁹I/¹²⁷I isotopic ratios as well as ¹²⁹I and ¹²⁷I concentrations in soils from several locations in Ukraine collected in 2006, 1996, 1993 and 1989, and from Slovenia, collected at various places in 2009 and 2006. The ¹²⁷I concentrations in surface soils from Ukraine were in the range 2.3–23.1?µg?g^?1 and for ¹²⁹I (11.1–245.7)?·?10^?8?µg?g^?1 dry matter with the highest value of 1.47?·?10^?3?µg?g^?1 found in a soil sample collected in Yaniv, Ukraine in July 1993. In soil samples from Slovenia ¹²⁷I concentrations ranged 0.73–130?µg?g^?1 and ¹²⁹I (8.0–245.7)?·?10^?8?µg?g^?1. The ¹²⁹I/¹²⁷I isotopic ratios of surface soils from Ukraine were in the range of the order of 10^?9–10^?5 and of 10^?10–10^?8 for soils from Slovenia. The highest isotopic ratio 13.6?·?10^?5 was found in a soil sample collected in Yaniv, Ukraine in July 1993.     

离子液体中不同形貌ZnO纳米材料的合成及表征

在不同的咪唑基离子液体中通过微波加热合成出了ZnO的片状聚集体、棒状聚集体和塔棒聚集体等纳/微米结构, 考察了不同合成条件对ZnO形貌的影响, XRD表明产物为六方相纤锌矿ZnO结构, SEM和TEM表明产物形貌主要分为片的聚集体和棒的聚集体, 电子衍射表明ZnO棒具有单晶结构, 片的聚集体的PL谱表明在室温下这种形貌的ZnO具有很强的绿光发射和弱紫外光发射现象.     

硫化锌精矿氧压酸浸渣中硫和铁的物相存在形式及其含量的测定

利用X射线衍射(XRD)方法分析研究了硫化锌精矿加压酸浸渣的物相存在形式,总结了硫和铁元素的存在形态,根据其相存在形式特点,提出并研究了在硫元素化学物相分析流程中同时测定铁物相的方法。实验表明,硫的相对误差小于5%,各物相有较好的重现性;铁物相分析误差不及硫,但多数小于5%,基本上符合分析测试要求,具有一定参考价值。建立了一种快速、有效表征硫和铁物相的方法,揭示了浸出渣中硫和铁元素赋存状态以及分布状态,为工艺研究、渣相处理以及理论分析提供了一种有效的表征方法。     

Some Considerations with Regard to the Quality of Results of Analysis of Trace Element Extractable Contents in Soil and Sediment

Abstract

Attention is drawn to the necessity to demonstrate accuracy of analytical results in order to make them comparable with results obtained elsewhere in the world. Besides the general aspects of quality management (e.g. within and between laboratories), attention is paid to the pitfalls that may occur in soil and sediment extract analysis. Especially the practical aspects of calibration are being dealth with.     

Controllable Synthesis of CaCO3 Micro/Nanocrystals with Different Morphologies in Microemulsion

Lens-like vaterite CaCO 3 microrings composed of CaCO3 nanoparticles were synthesized via a micro-emulsion-mediated route at room temperature with ethanol and n-hexanol as co-surfactant. This process did not de-mand any additional energy such as heating or continuous agitation. It was the first time to use ethanol as co-surfactant in the synthesis of micro or nanomaterials. And the ethanol was believed to play an important role in the aggregation fashion of CaCO 3 nanoparticles. Moreover, shuttle-shaped nanorods, hexagonal nanoplates, and rice-like nanoparticles were also fabricated by modulating the growth parameters. Additionally, the introduce of ethanol into microemulsions as co-surfactant may be generalized as a novel green route to control the structure of other functional materials.     

反相胶束法控制合成不同形貌半导体Ag_2S纳米晶

采用水 (溶液 ) /TritonX 10 0 /环已烷 /正戊醇反相胶束体系 ,制备出不同形貌的Ag2 S纳米晶 ,其中合成出的直径为 5 0～ 10 0nm、长度为 2 .0～ 3.5 μm、长径比为 2 0～ 70的纯相Ag2 S纳米棒为首次报导 .就不同ω0 、反应物浓度和陈化时间等因素对合成Ag2 S的形貌和尺寸的影响进行了研究 ,获得了控制合成不同形貌Ag2 S纳米晶的反应条件 .所得产物利用透射电子显微镜分析进行了表征     

超声辅助萃取/气相色谱-质谱测定沉积物中的对苯二酚

建立了超声波辅助萃取,乙酸酐衍生化后用气相色谱-质谱(GC - MS)法测定沉积物中对苯二酚的分析方法.对超声辅助萃取影响因素如萃取溶剂、超声功率、萃取次数和萃取时间进行了优化.在优化条件下,对苯二酚的回收率为85%～92%,相对标准偏差(RSD)为3.0% ～7.2%,线性范围为0.05～10 mg/L,检出限为12...