电感耦合等离子体发射光谱仪测定磷酸中铅、砷、镉、铬

在GB/T2091—2008[1]中严格规定了工业磷酸中重金属的限量,采用砷斑法及比色法测定,但是由于砷、铅、镉、铬微量元素都要分别测定,分析时间较长。使用电感耦合等离子体发射光谱法可同时测定磷酸中的砷、铅、镉、铬,有效缩短了分析时间。笔者建立的磷酸中砷、铅、镉、铬等微量元素的电感耦合等离子体发射光谱分析方法与参考文     

电感耦合等离子体质谱法测定菊花中镉、铬、铅和砷4种有害元素

菊花样品通过微波消解预处理,采用ICP-MS测定样品中镉、铬、铅和砷元素含量。结果显示,该方法RSD<4%,加标回收率在96.3%～104.5%。该方法便捷、灵敏度好、准确性高,能够同时测定菊花样品中多种有害元素。菊花中镉、铬、铅和砷的含量分别在0.100 3～0.209 3,0.554 0～1.663 7,0.148 3～1.070 7和0.063 0～0.137 0 mg/kg范围内,符合国家相关限量标准。     

塑料中铅、镉、铬、汞四种重金属遴选设立的研究

通过比较研究国内外法律、法规强制性标准对各种塑料中的砷、铅、铬、镉等四种重金属限定值及这四种重金属对孕妇和婴幼儿的影响,形成塑料材料中铅、镉、六价铬、汞限量参考数值,为婴幼儿制品、食品接触塑料制品、药品包装材料、日用塑料制品及其他工业塑料材料中铅、镉、六价铬、汞含量的测定提供技术保障。     

嵊泗县枸杞养殖贻贝残留重金属的监测与污染评价

分析和评价了嵊泗县枸杞岛贻贝残留重金属"汞、砷、镉、铬、铅"的含量现状,并对潜在的污染风险进行评价。研究结果表明:嵊泗县枸杞岛两个采样站位的养殖贻贝中重金属"汞、砷、镉、铬、铅"的含量相当,均小于食品中污染物的限量标准;研究还发现,嵊泗枸杞贻贝受"汞、砷、铬"的污染较小,重金属含量符合一类海洋生物质量标准,而贻贝中"镉、铅"的含量已超过一类海洋生物质量标准,存在污染风险,应加强监测。     

对肥料中重金属元素含量测定的研究

介绍《肥料中砷、镉、铅、铬、汞限量》国家标准制定的目的意义、技术要求和试验方法 ,并将砷含量测定采用二乙基二硫代氨基甲酸银分光光度法或砷斑法 ,镉、铅、铬、汞含量的测定采用原子吸收分光光度法作为测定肥料中重金属元素的推荐方法     

海南不同产地眼树莲中4种重金属元素含量分析

目的对海南不同产地眼树莲中砷、汞、铅、镉4种重金属元素含量进行测定。方法采用氢化物原子荧光法测定眼树莲中重金属砷、汞、铅、镉元素的含量。结果镉未检出,砷、汞、铅含量极低,且均远低于《药用植物及制剂进口绿色行业标准》中重金属的限量标准。但不同来源的海南眼树莲重金属含量存在一定差异。结论原子荧光光谱法快速、简便、准确、稳定,可用于眼树莲中重金属含量测定。     

我国颜料标准中重金属安全限量标准的未来走向

我国颜料领域标准采用国际标准的采标率约为59％,其中涉及颜料中重金属限量的标准基本采用了国际标准,但相关指标仍有差异。我国标准GB／T3184—2008对重金属的限量要求与发达国家的标准要求一致,但GB／T3185—1992和GB／T3494—1996中缺乏对氧化锌颜料中重金属铅和镉的限量要求,GB／T6890-2000中缺少对锌粉颜料中砷的限量要求,HG2351—1992中缺少对镉红颜料中重金属汞的限量要求,     

ICP-MS法测定大米中铬、砷、镉、汞、铅的含量

采用微波消解法处理大米样品,应用ICP-MS测定了大米中铬、砷、镉、汞、铅等5种重金属元素的含量,结果表明:5种元素的检出限范围为0.05~5.43μg·kg-1;线性关系良好(r0.9993);回收率为94.9%~106.1%,RSD小于5.0%。该方法准确、灵敏、简便,适用于大米中铬、砷、镉、汞、铅等元素含量的检测。     

ICP-MS法测定美白祛斑类化妆品中的汞、砷、铅、镉和铬

为建立电感耦合等离子体质谱法(ICP-MS法)测定美白祛斑类化妆品中汞、砷、铅、镉、铬5种元素含量的方法,将样品经硝酸和过氧化氢微波消解后,用电感耦合等离子体质谱仪测定美白祛斑类化妆品中重金属汞、砷、铅、镉、铬的含量。结果发现:汞、砷、铅、镉、铬混合标准溶液在0～100 ng/mL范围内线性关系良好,相关系数为0.9998～1.0000,各元素最低检出浓度均小于0.1 mg/kg,各元素加标回收率在97. 5%～108. 6%之间。该方法简便、灵敏,有较低的检出限,符合方法学验证要求,可用于美白祛斑类化妆品中汞、砷、铅、镉、铬的同时测定。     

土壤中主要重金属污染物的迁移转化及治理

介绍了土壤中主要重金属污染物汞、镉、铅、铬、砷在土壤中的主要存在形式、来源、迁移及转化过程。对土壤中主要重金属污染物提出了治理方法。     

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