Selenium speciation in soil extracts using LC-ICP-MS

Selenium (Se) speciation in soil affects its bioavailability to crops. An analytical procedure for the determination of inorganic Se species (selenite and selenate) in soil extracts by anion-exchange liquid chromatography (LC) with ICP-MS detection has been developed, with 10-fold higher sensitivity than existing HGAAS-based soil Se measurements. A comparison of phosphate extraction solutions on agricultural soils amended with 20?µg?kg^–1 selenate or selenite was carried out, and a 0.016?M?KH₂PO₄ extraction solution is recommended. Recovery of selenate was >91%; however, selenite recovery ranged between 18.5% and 46.1%, due to rapid binding to the soil. Soil preparation did not have a significant (p?>?0.05) effect on the extractability of the selenate or selenite amendments. The stability of Se species in the phosphate extracts was variable, depending on temperature and storage time. Therefore, immediate (<1?h) analysis of the soil extracts is preferable. The method developed was applied to the determination of extractable Se from six arable soils in the UK. Extractable Se levels in these soils ranged between 6 and 13?µg?kg^–1 consisting of selenite and some soluble organic Se.     

Comparison of ICP-AES and ICP-MS for the Analysis of Trace Elements in Soil Extracts

Abstract

The extraction of the chemical species Cr, Ni, Cu, Zn, Cd, and Pb, operationally defined, from a sewage sludge treated soil with various extractants (ammonium acetate, acetic acid and EDTA) has been studied by using two analytical techniques: inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma atomic emission spectroscopy (ICP-AES). A comparison of the mean values measured by the two techniques with the t-criterion reveal that the differences are not significant in all the extractants mentioned above.

Results are also compared with data from a laboratory intercomparison exercise organized in the BCR-programme (Bureau Communautaire de Reference) and discussed. A fast screening of the concentration of other trace metals could be provided by ICP-MS with good precision and low detection limits.     

Trace element speciation by ICP-MS in large biomolecules and its potential for proteomics

Latest studies on the chemical association of trace elements to large biomolecules and their importance on the bioinorganic and clinical fields are examined. The complexity of the speciation of metal-biomolecules associations in various biological fluids is stressed. Analytical strategies to tackle speciation analysis and the-state-of-the-art of the instrumentation employed for this purpose are critically reviewed. Hyphenated techniques based on coupling chromatographic separation techniques with ICP-MS detection are now established as the most realistic and potent analytical tools available for real-life speciation analysis. Therefore, the status and potential of metal and semimetals elemental speciation in large biocompounds using ICP-MS detection is mainly focused here by reviewing reported metallo-complexes separations using size-exclusion (SEC), ion-exchange (IE), reverse phase chromatography (RP) and capillary electrophoresis (CE). Species of interest include coordination complexes of metals with larger proteins (e.g. in serum, breat milk, etc.) and metallothioneins (e.g. in cytosols from animals and plants) as well as selenoproteins (e.g. in nutritional supplements), DNA-cisplatin adducts and metal/semimetal binding to carbohydrates. An effort is made to assess the potential of present trace elements speciation knowledge and techniques for "heteroatom-tagged" (via ICP-MS) proteomics.     

Evaluation of Ammonium Oxalate for Fractionating Metallic Trace Elements in Soils by Sequential Extraction

Abstract

Ammonium oxalate is largely used to extract the trace elements bound to Mn-oxides, amorphous compounds and crystalline Fe-oxides. The objective of this work was to evaluate the selectivity and the efficiency of ammonium oxalate for extracting Cd, Cu, Ni, Pb and Zn by sequential extraction of soils. For this purpose, three schemes were selected and applied to three different soil samples of the Swiss Jura. Each extraction scheme consisted of six steps, where different reagents were used to extract Cd, Cu, Ni, Pb and Zn bound to the Mn and Fe compounds. The results showed that metallic trace elements extraction with ammonium oxalate are very dependant on the metal studied. The reason could be the capability of oxalate to form stable complexes with the metals considered which sometimes are only slightly soluble.     

广东四会十月桔种植土壤中微量元素分析

用火焰原子吸收分光光度法和阳极溶出伏安法对广东四会９个地区的十月桔及其种植土壤中１１种元素进行了测定。结果表明,四会地区十月桔富含人体有益元素,而有害元素含量极低,是一种有较高营养价值及安全的食品,土壤中各元素含量范围广,但十月桔对同一元素具有相应的富集特征。     

川芎中微量元素的初级形态分析

中药川芎是伞形科藁木属川芎的干燥根茎,用于活血化瘀,治疗缺血性心、脑血管疾病及慢性心衰、肾衰,疗效良好。目前对于川芎及其提取物的药理作用、临床应用及其化学成分的研究较多,     

ICP-MS法测定彭泽贝母中微量元素的含量及形态分析

目的:测定彭泽贝母中微量元素含量,研究彭泽贝母中微量元素的存在形态,探讨微量元素的含量和形态.方法:采用HNO3-H2O2微波消解体系,电感耦合等离子质谱法(ICP-MS)测定彭泽贝母中铅、钙、铁、锰、锌、镉、钡、铬等10种微量元素的含量,初步探究微量元素的存在形态.结果:Ca元素在彭泽贝母中含量最高,而Mo元素含量最低;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.结论: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.     

微量元素改变中国的科学面貌（下）——为中国微量元素科学研究会成立三十周年而作

以矿物药为标志、以炼丹术为核心的中国古代微量元素研究曾领先世界绵延2000年之久,公元17世纪后逐渐走向衰落。20世纪六十年代,中国现代微量元素研究崛起,取得了令世人瞩目的成就。微量元素改变中国的科学面貌,大数据可以作证。从知识普及、期刊论文和会议论文、成果和专利、学位论文、基金项目、图书出版、元素形态分析、微量元素组学研究八个方面作了诠释。     

微量元素改变中国的科学面貌（上）——为中国微量元素科学研究会成立三十周年而作

以矿物药为标志、以炼丹术为核心的中国古代微量元素研究曾领先世界绵延2000年之久,公元17世纪后逐渐走向衰落。20世纪六十年代,中国现代微量元素研究崛起,取得了令世人瞩目的成就。微量元素改变中国,大数据可以作证。从知识普及、期刊论文和会议论文、成果和专利、学位论文、基金项目、图书出版、元素形态分析、微量元素组学研究八个方面作了诠释。     

Arsenic speciation in hair extracts

Ingested arsenic is known to be not only excreted by urine, but to be stored in sulphydryl-rich tissue like hair, nail or skin. We developed an extraction method for arsenic species from these tissues and studied the stability of different arsenic species during the extraction process. Inorganic and pentavalent methylated arsenic was found to be stable under the extraction conditions, whereas trivalent methylated arsenicals and the thio-analogue of DMA^V (DMAS) showed reduced stability. The absorption ability of hair for these different species was studied as well. Inorganic arsenic is better absorbed by hair than monomethyl- or dimethyl-arsenicals, whereby the trivalent forms are taken up better than the pentavalent forms. Independent of which methylated arsenical was used for the incubation, the pentavalent form was always the dominant form after extraction. Hair and nail samples from humans suffering from chronic arsenic intoxication contained dominantly inorganic arsenic with small and strongly varying amounts of DMA^V and MA^V present. DMAS was only found in some nail sample extracts containing unusually high amounts of DMA^V and is believed to be formed during the extraction process.     

蒙药匝迪-5中有害金属元素的初级形态研究

采用ICP-ASE法对匝迪-5中的Cu,As,Cd,Hg和Pb元素进行了初级形态分析。结果显示Pb和Cu在头煎液和二煎液中的含量之和分别为0.25mg/kg和0.53mg/kg。As,Cd和Hg未检出;人工胃液中Pb的含量为0.02mg/kg,Cu的含量为0.37mg/kg。说明匝迪-5煎煮液和人工胃液中重金属均低于国家药典标准的要求。     

Evaluation of extraction methods for arsenic speciation in polluted soil and rotten ore by HPLC-HG-AFS analysis

Three extraction systems including shaking, ultrasonic and microwave-assisted extraction were evaluated. Water and phosphate buffer were tested for the extraction of arsenic compounds in polluted soil, describing the water-soluble or plant-available fraction. The stabilities and recoveries of various arsenic species indicated that no obvious changes of species occurred during the extraction process. The raw extracts were cleaned up by C₁₈ cartridge before analysis. Having optimized the extraction conditions, the arsenic species in polluted soil and ore from the different pollution sources were extracted by microwave-assisted extraction with 0.5 M phosphate buffer as extractant. Arsenic species were quantitatively determined by high performance liquid chromatography on-line coupled with hydride generation atomic fluorescence spectrometry (HPLC-HG-AFS). As(III) and As(V) were the major arsenic species in the polluted soil samples resulting from irrigation by waste water. As^V was the only form found in the rotten ore sampled in mining area. During the extraction process, the recoveries of spiked As(III), As(V), DMA(V) and MMA(V) were 85.4 ± 7.2%, 80.2 ± 6.7%, 101.6 ± 6.7% and 98.8 ± 9.1%, respectively, showing that most water-soluble arsenic could be measured.     

微量元素与高血压

论述了微量高血压的关系,着着讨论了铅、镉、硒、锌与高血压的关系。     

黄芪中微量元素的形态分析

按照传统煎煮法对中药黄芪中铜、锌、铁、镁、钙和铬6种元素进行提取;用微孔滤膜分离提取液中的可溶态与悬浮态;利用大孔吸附树脂柱对可溶态中的有机态与无机态进行分离;采用火焰原子吸收光谱法对各种形态中的6种元素进行测定。结果显示:黄芪中6种元素的总提取率在44.0%~74.4%,浸留比在79·4%~293.8%,悬浮态颗粒吸附率在10%左右,可溶态中铬的有机态与无机态的比例为114.6%,铜、锌、铁、镁、钙的有机态与无机态的比例在3.7%~43.5%。该法对各元素的加标回收率在96.8%~103.1%;相对标准偏差小于1.5%。     

微量元素与糖尿病

糖尿病是一种常见病。成人糖尿病患病率约为３％,亦即现有糖尿病人达１亿左右。估计到２０１０年,全球糖尿病人将超过２亿。糖尿病的发展涉及多种病理过程,已有令人信服的证据表明,微量元素在胰岛素的生成和作用以及糖尿病人的能量底物代谢中起着极为重要的作用。本文从糖尿病行病学、微量元素在胰岛素代谢中的作用、糖尿病人的微量元素含量变化和糖尿病的微量元素治疗等四个方面综述了微量元素与糖尿病的关系。参考文献７０,表     

癫痫与微量元素

评论了微量元素锌,铜,铁,锰与癫痫的关系。癫痫患者血浆中锌、铜、铁含量比正常对照组增高,锰含量降低。锌／铜比值较正常对照组明显降低。而癫痫患者发锌,铁含量比正常人对照组升高,发铜,锰含量降低。     

微量元素与心血管疾病Ⅱ.微量元素在心血管病中的可能作用及机制

心血管病的发生和发展至少与体内35例元素不平衡有关，本文重点叙述了镁，钙，铜，铬，硒，锰，铁，锌，锶，铅等10种元素在心血管病中的可能作用及机制。附5图，20表和63篇参考文献。     

豫产桔梗的土壤与药材中部分微量元素含量与分析

为了解桔梗中微量元素含量特征,研究土壤中微量元素对桔梗药材道地性的影响,采用原子吸收光谱法、冷原子荧光法、双道原子荧光法对不同产地的桔梗药材及生境土壤中8种微量元素含量进行了测定,所得数据用SPSS 11.0软件进行分析比较。结果表明,不同产地的桔梗微量元素含量有差异;药材与土壤中微量元素之间具有相关性。桔梗对土壤中微量元素是主动与被动相结合的有选择吸收。     

微量元素与病毒性肝炎

微量元素参与机体各种酶及活性物质的代谢，从多方面影响着人的生命过程。肝脏是人体的重要代谢脏器，对微量元素的代谢关系更为密切。病毒性肝炎患者血清硒，锌均明显降低，铜元素高于正常。因此测定患者机体内的微量元素含量，为诊断及治疗提供新的途径和措施，可及时纠正患者体内微量元素的盈缺，有助于改善肝细胞功能及增强机体免疫力。     

微量元素与高血压Ⅰ.高血压病人的元素含量异常

高血压是脑卒中和冠心病的主要危险因素，我国现有1．2亿人正受到高血压的威胁。大多数高血压是可以防治的。膳食防治高血压的本质是维持元素平衡或纠正破坏了的元素平衡关系。本文简述了我国高血压流行情况、不同血压水平的心脑血管病发病危险、血压与微量元素的相关关系、高血压患者的元素含量异常，以及高血压的元素食疗防治。附1图、33表、44篇参考文献。