模拟汽油中痕量磷元素的ICP-OES和ICP-MS方法测定

采用浓硝酸结合过氧化氢的酸消解体系对模拟汽油样品进行了微波消解前处理,建立了电感耦合等离子体发射光谱(ICP-OES)和电感耦合等离子体质谱(ICP-MS)准确测量模拟汽油中痕量磷元素的分析方法,整个过程安全、高效、无污染。结果表明,ICP-OES和ICP-MS测量痕量磷元素(50～400μg/kg)具有良好的线性,相关系数优于0.999 9,方法检出限为2～3μg/kg;ICP-OES和ICP-MS测得模拟汽油中痕量磷元素的含量分别为0.450 7、0.444 mg/kg、加标回收率为96.2%～106.6%,两种方法测量结果具有良好的一致性。以ICP-MS测定方法为例,评定了模拟汽油中痕量磷元素的测量结果不确定度(2.6%,k=2),测量重复性和工作标准溶液配制是测量结果不确定度的两个主要来源。所建立的模拟汽油中痕量磷含量准确测量方法为进一步的汽油中痕量磷元素标准物质研制积累了良好的技术基础。     

微波消解—ICP-MS测定稻米中的铅、砷、汞、镉

探讨了微波消解条件、ICP-MS(电感耦合等离子体质谱)仪器工作条件及影响测定的因素。用微波消解法进行样品的消解,直接用ICP-MS测定稻米样品中的铅、砷、汞和镉4种微量重金属的含量。结果表明,该法对各微量重金属元素的检出限为0.01~0.03μg/L,相对标准偏差为0.3%~3.8%,加标回收率均在90%以上。方法操作简便、分析速度快、灵敏度高,各项分析性能指标均达到要求,用于大米中微量重金属元素的分析,有助于了解和预警稻米的安全性,结果满意。     

ICP-OES测定选择性加氢催化剂中的铂、钯含量

选择使用微波消解仪法消解选择性加氢催化剂样品,结合电感耦合等离子体収射光谱仪(ICP-OES)测定选择性加氢催化剂中的Pt、Pd元素含量。系统考察了微波消解法消解样品条件,优化了电感耦合等离子体収射光谱仪(ICP-OES)的工作条件,采用内标校正标准工作曲线法,建立了ICP-OES法测定选择性催化剂中Pt、Pd元素含量的分析方法。结果表明,以8 mL硝酸和2 mL氢氟酸体系混合酸体系,微波消解法能够充分消解选择性加氢催化剂样品;测定选择性加氢催化剂中Pt含量:6.489～6.703 mg/L、Pd含量:14.85～15.31mg/L;相对标准偏差(RSD)分别为铂:1.216%、钯:1.217%;样品加标回收率分别为Pt:99.25%～101.26%、Pd:99.58%～102.24%。ICP-OES测定方法用于可以应用于选择性加氢催化剂中Pt、Pd元素含量的测定,分析快速,结果准确,已应用于生产分析中。     

电感耦合等离子体质谱法测定稀土回收料中15种稀土元素含量

利用电镜能谱分析(EDS)对样品的组成及含量做半定量分析。基于该结果设计样品消解方案，结合电感耦合等离子体质谱法(ICP-MS)测定稀土回收料中15种稀土元素，再采取钆元素通过氨气反应质量转移模式消除基体的干扰。结果显示：15种稀土元素校准曲线相关系数大于0.999 7。通过回收率实验，样品的回收率在95%～110%之间。该测试结果与电感耦合等离子体发射光谱法(ICP-OES)取得结果基本一致。     

电热板消解ICP-MS测定生物质中的砷

选择硝酸-过氧化氢消解体系于电热板上对生物质样品进行消解,采用电感耦合等离子体质谱(ICP-MS)测定消解液中砷的含量并采用标准加入法进行定量分析,以消除基体干扰。结果表明,电热板消解ICP-MS法测定生物质中的砷,具有准确度高、精密度好的特点,标准加入法的线性回归方程Y=16390X+443035,相关系数(r)=0.9998;样品加标回收率在102%～104%之间;6次平行测定的标准偏差RSD为1.5%,对生物质样品中砷的检出限为0.0109 mg/kg。本研究建立了一种快速准确测定生物质样品中砷含量的方法。     

电感耦合等离子体原子发射光谱法测定印染污泥中的重金属元素

选取某印染厂污泥作为样品,经硝酸-高氯酸-硫酸消解体系进行微波消解后,采用电感耦合等离子体原子发射光谱法对样品中铜、铬、锌、镉、铅5种有害重金属元素进行定量分析。方法相对标准偏差小于4.0%,加标回收率在93.8%～108.2%。     

ICP-OES法测定铝镍钴磁钢铝、镍、钴、铁和铜含量

采用微波消解电感耦合等离子体原子发射光谱(ICP-OES)法测定了铝镍钴磁钢废料中的铝、镍、钴、铁和铜元素。结果表明:微波消解以硝酸为介质溶解样品所得溶液清亮,无残渣;铝、镍、钴、铁和铜元素的线性良好,相关系数在0.9997～0.9999之间,标加回收率在98.84%～102.00%之间,方法精密度RSD≤0.21%。该方法操作简单易行、灵敏度高、重复性好,与x-荧光光谱法、化学容量法的对照结果表明,测试结果可靠性强。     

ICP法测定土壤中4种痕量重金属元素实验研究

采用石墨消解仪对土壤进行前处理,建立电感耦合等离子体发射光谱法同时测定土壤中铍、锑、钼、银等4种痕量重金属元素含量的方法。该方法相关系数均在3个9以上,测定国家标准物质土壤样品,测定值与保证值一致,相对标准偏差0.3%～11.5%,检出限为0.005～0.1 mg/kg,加标回收率为87%～95%。     

电感耦合等离子体质谱法测定AES中的Cu和Fe

为了建立脂肪酸聚氧乙烯醚硫酸钠中(AES)Cu和Fe金属元素含量的测定方法,用微波消解法处理样品,电感耦合等离子体质谱法测定AES中的Cu和Fe,最终建立了电感耦合等离子体质谱法同时测定AES中Cu和Fe金属元素含量的方法。方法的检出限为0.0004898～0.0041500μg/L,相对标准偏差(RSD)小于1.0%,加标回收率为96.8%～99.8%。该研究结果为AES中Cu和Fe重金属元素的定量分析提供理论依据。     

ICP-MS法测定电子级高纯盐酸中的痕量元素

为了有效检测电子级高纯盐酸中的痕量元素，利用电感耦合等离子体质谱法(ICP-MS)进行测定，用全基体进样系统(AMS)进样，用标准加入法进行上机检测，无需前处理，避免了在样品前处理时的污染问题。电感耦合等离子体质谱法可以消除多分子离子干扰，降低检出限，提高定量准确性。该方法的检出限为0.05～5.4 ng/L,加标回收率为96%～108%,稳定性RSD均不超过5%;操作简单，结果可靠，适用于高纯盐酸中痕量元素的快速测定。     

水镁石、水菱镁石和斜方云石资源、加工与应用

对水镁石、水菱镁石和斜方云石资源及其加工和应用进行了评述。包括上述资源的发展历史、化学组成和物性参数、资源储量和矿石品位、生产加工以及在不同领域(如镁质阻燃剂、中和剂、重金属离子脱除剂、镁肥、饲料添加剂等)的应用,并对它们的发展前景进行了展望。     

Pd-, Ni-, Fe-, and Co-Catalyzed Cross-Couplings Using Functionalized Zn-, Mg-, Fe-, and In-Organometallics

The development of new methods for preparing polyfunctional organometallics has made a broad range of such reagents available for various transition metal-catalyzed cross-couplings. An overview of the most general preparation methods will be presented. Applications to practical cross-coupling procedures will be covered, emphasizing the functional group compatibility and the reaction scope.     

Bioaerosol Science,Technology, and Engineering: Past,Present, and Future

Poor air hygiene as a result of bioaerosol contamination has caused diverse forms of adverse health effects and diseases. In addition, global biosecurity is threatened by purposeful use of biowarfare agents and the vulnerability of people to the infectious agents. Accordingly, developments in high-volume biosampling, including aerosol-to-hydrosol techniques with low cut-off size, real-time bioaerosol detection, adequate biological quantification, and exposure control, as well as the investigation of the link between disease outcome and bioaerosol exposure, are current areas of bioaerosol research. Although milestone progress has been achieved both in bioaerosol sampling and analysis techniques since late 1800s, compared to atmospheric chemistry the bioaerosol field is still understudied. This is partially because of the lack of both bioaerosol scientists and multidisciplinary collaboration. It is becoming necessary to develop a pool of scientists with different expertise, e.g., bioaerosol scientists, environmental engineers, biomedical engineers, epidemiologists, microbiologists, chemists, physicists, as well as researchers in other engineering fields, in mitigating bioaerosol-related adverse health effects, eliminating diseases, and preventing and controlling epidemic outbreaks. This work is conducted to broadly review current state-of-the-art sciences and technologies in the bioaerosol field. In tackling the challenges ahead, the review also provides perspectives for bioaerosol research needs, and further reminds bioaerosol scientists of those existing technologies in other fields that can be leveraged. In view of the past, forward-looking hypotheses and revolutional perspectives are needed to be formed in order to allow the bioaerosol research have major impacts in the academic community in this new millennium.     

Stable silyl, germyl, and stannyl cations, radicals, and anions: heavy versions of carbocations, carbon radicals, and carbanions

The rapidly growing chemistry of the cations, radicals, and anions based on the group 14 elements heavier than carbon (Si, Ge, Sn, and Pb) is one of the most important organometallic fields. Recent developments in this research area moved such species from the class of short-lived reactive intermediates to the class of easily accessible, isolable, and fully characterizable compounds. In this Account, we deal with the major accomplishments in the field of the stable representatives of "heavy" cations, radicals, and anions.     

Breaking, making, and twisting of chemical bonds in gas, liquid, and nanocavities

In this Account, we recount on our studies of 1'-hydroxy-2'-acetonaphthone (HAN, a proton transfer prototype molecule) in gas, solutions, and nanocavities. The internal H-bond photoreaction in HAN leads to a keto type structure, and following its formation, an internal twisting motion gives birth to keto rotamers. Theory, temperature, and solvent effects on its photodynamics show the involvement of efficient radiationless processes in both keto structures. When HAN is caged in a cyclodextrin nanocavity, the spectroscopy, photodynamics, and issues of twisting motion are strongly affected and could be tuned: a behavior relevant to those of many chemical and biological systems.     

Polystyrene nanocomposite materials: Preparation,morphology, and mechanical,electrical, and thermal properties

In this study, we prepared polystyrene (PS) resin nanocomposites with antistatic properties by melt‐blending PS with nanoscale zinc oxide (ZnO). The effects of nanoscale ZnO on the electrical and physical characteristics of the PS nanocomposites were investigated. Two kinds of nanoscale powders, spherical zinc oxide (s‐ZnO) and zinc oxide whisker (w‐ZnO), were selected. The coupling agents vinyltriethoxysilane (VTES) and phenyltriethoxysilane (PTES) were used to improve the compatibility between the nanopowders and PS resin. The addition of s‐ZnO and w‐ZnO improved the antistatic characteristics of the materials. The surface resistivities of the s‐ZnO and w‐ZnO nanocomposites were significantly reduced by modification with VTES and PTES. The addition of ZnO nanopowder increased the flexural modulus and reduced the flexural strength. The silane coupling agents improved the flexural properties of the nanocomposites. The glass‐transition temperatures and thermal degradation temperatures of the ZnO/PS nanocomposites increased with ZnO content. Treatment with silane increased the glass‐transition temperatures and thermal degradation temperatures of the composites. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2266–2273, 2005