高压消解-电感耦合等离子体原子发射光谱法测定电子电气产品塑料中的铅、镉、铬和汞

采用密闭高温压力罐技术，将电子电气产品中塑料样品用硝酸-氟硼酸-过氧化氢在180℃的温度下加热4h溶解后，用全谱直读的电感耦合等离子体原子发射光谱（ICP-AEs）同时测定塑料中的铅、镉、铬和汞，方法的检测限为0．0015～0．014μg／mL，方法的回收率和精密度分别为87．7％～100．8％和0．12％～4．60％，实际样品的检测结果较为满意。该方法快速简便，可应用于电子电气产品塑料中的铅、镉、铬和汞的日常检验。     

微波消解－石墨炉原子吸收法测定鱿鱼中的铅和镉

铅和镉的检测方法归纳起来有原子吸收光谱法、电感耦合等离子体原子发射光谱、质谱法、分光光度法等,本文研究了硝酸－双氧水体系对鱿鱼样品微波消解微波消解石墨炉原子吸收分光光度法测定鱿鱼中的铅和镉的方法,选择正磷酸作为基体改进剂,寒曼扣背景,结果表明本方法简便易操作、精密度好、准确度高。铅和镉的方法检测限为0．017μg／g和0．00055μg／g,铅、镉样品回收率分别在80．0％～98．0％和83．0％～96．1％之间。精密度和重现性均能满足试验要求。     

微波消解-ICP-MS测定蜂胶软胶囊中砷铅镉

采用微波消解法对蜂胶软胶囊样品进行处理,研究了微波消解和ICP-MS的测定条件,建立了微波消解-电感耦合等离子体质谱法测定蜂胶软胶囊中砷、铅,镉的方法。砷、铅、镉测定下限分别为0．08、0．02和0．02μg／g,RSD均小于3％,加标回收在99％～102％之间,方法用于实际样品分析。     

一次性输液器中金属元素的测定与分析

目的测定输液器中钡、铬、铜、铅、锡、镉六种金属元素的含量。方法参照GB 8368-2005的样品处理方法,利用ICP-MS对其进行金属元素分析。结果在全国范围内随机抽取的50批供试品中,该六种金属元素含量全部符合要求:钡、铬、铜、铅、锡的总含量1μg·m L~(-1),镉的含量0.1μg·m L~(-1)。结论通过随机测试分析,可为输液器的安全使用和监管提供一定数据参考。     

微波消解-电感耦合等离子体发射光谱法同时测定铜阳极泥中的有害元素Pb、As、Cd、Cr

建立了一种可以同时、准确测定铜阳极泥中有害元素铅、砷、镉、铬的方法。铜阳极泥样品经王水微波消解,定容后采用电感耦合等离子体发射光谱法进行分析,本研究探讨了称样量和分析谱线对检测结果的影响。Pb、As的线性范围为0-100μg/mL,0-60μg/mL,Cr、Cd的线性范围为0-30μg/mL,4种元素的检出限在0.00054-0.053μg/mL之间,测定下限在0.0018-0.176μg/mL之间,本方法中铅、砷、铬、镉的回收率在91.7%-108.3%之间,Pb、As、Cd、Cr的相对标准偏差为0.0036～0.00972,0.00520～0.00998,0.0099～0.068,0.0066～0.059。     

微波消解-火焰原子吸收光谱法测定土壤中的铅、镍、铜

应用微波消解和火焰原子吸收光谱法测定土壤中的铅、镍、铜。考察了土壤的最佳微波消解条件,样品用HNO3-HCl04-HF混合酸经微波消解后,溶解时间由原来的3～5h缩短到3min。以原子吸收光谱法测定土壤中铅、镍、铜。铅、镍、铜的测定波长分别为283．3、232．0、324．8nm;检出限分剐为0．0005、0．0004、0．0001μg／mL;工作曲线的线性范围为0．002～30．00μg／mL,0．001～50．00μg／mL,0．001～6．00μg／mL。方法用于土壤样品的分析,铅、镍、铜的相对标准偏差分别小于0．31％、1．52％、3．29％,回收率在98．00％～102．00％。     

天然沸石处理含铅、镉废水的试验研究

天然沸石经改性后对铅、镉有较好的吸附能力，当铅的浓度为2mg／L，沸石用量30g，动态变换3小时，吸附效率达90％以上，吸附容量达5mg／g；当镉的浓度为l00mg／L，沸石用量l0g，动态交换24小时，吸附效率可达99．8％以上。在450℃时处理的沸石吸附效果最佳，改性后的沸石对铜的吸附具有较好的选择性。     

石墨炉原子吸收法测定化探样品中镉

本文以氢氟酸-硝酸-2高氧酸-硫酸分解化探样品,在25％HCl介质中测定镉。镉的测．定下限为0．0052（Cd）μg／g。镉0．20μg／g样品,其相对标准偏差分别为2．88%。     

2-羟基-5-氟-3-磺酸基苯基重氮氨基偶氦苯的合成

合成了2-羟基-5-氯-3-磺酸基苯基重氮氨基偶氮苯，并研究了它与镉（Ⅱ）的显色反应。实验表明，在Triton X-100的存在下，pH11．2的Na2B4O7-NaOH缓冲介质中，镉（Ⅱ）与之形成1：3的红色配合物，在528nm处有最大吸收。表观摩尔吸光系数为2．46×10^5L·mol^-1,cm^-1，镉（Ⅱ）在0～20μg／25mL范围内遵守比耳定律。方法应用于废水中微量镉的测定，结果令人满意。     

微波消解——DUO-ICP-AES测定电子电气产品塑料中的铅、镉、铬和汞的方法研究

采用微波消解技术,将电子电气产品中的塑料样品用硝酸-氟硼酸-过氧化氢在210℃的温度下加热约1h溶解后,用全谱直读DUO-ICP-AES同时测定塑料中铅、镉、铬和汞,方法的检测限为0.0015~0.011μg/m l,该方法的回收率和精密度分别为91.2%~100.5%和0.45%~3.18%,2h内实际样品的检测结果较为满意。该方法快速简便,可应用于电子电气产品塑料中的铅、镉、铬和汞日常检验。     

无钴黑色陶瓷颜料中铬含量测定的新方法

本文以盐酸羟胺作还原剂,研究了三价铬与二甲酚橙的显色反应,结果发现Cr3 在0～80滋g/50ml范围内,其吸光度与Cr3 含量成正比相关,用于无钴黑色陶瓷颜料中铬含量的测定,作出了回归方程,且进行了显著性检验,获得了理想的结果。     

Effects of chloride, bromide and iodide ions on internal stress in films deposited during high speed nickel electroplating from a nickel sulfamate bath

The effects of chloride, bromide and iodide additions on the internal stress developed in nickel films deposited during high speed electroplating from nickel sulfamate baths operated close to the nickel ion limiting current density were investigated. The variations in internal strain in the films were detected in situ using a resistance wire-type strain gauge placed on the reverse side of the copper substrate. The film resistance on the as-plated electrodes was measured using an electronic current interrupter technique. The effects of chloride, bromide, and iodide additions could be classified into two groups: (a) chloride and bromide ions, and (b) iodide ions. For chloride and bromide additions over the concentration range of 0.1 to 0.5M, the nickel deposits exhibited a block- and pyramid-like texture with a (200) crystal orientation. The internal tensile stress developed in 20m thick nickel films deposited in the presence of these two halides was as low as 140–170MPa. Conversely, for additions of iodide, at iodide concentrations greater than 0.1M the deposited nickel exhibited a fine granular texture of disordered crystal orientation. The internal tensile stress developed in 20m thick nickel films deposited from these latter baths tended to rise with increasing iodide concentration to values considerably higher than those observed at similar concentrations of NiCl₂ or NiBr₂.     

多级气液鼓泡塔中筛板结构对气垫层高度及局部气含率的影响

采用压差法和双电导探针法考察了筛板结构对f300 mm多级鼓泡塔中筛板下侧气垫层高度和筛板上下两处局部气含率的影响. 结果表明,气垫层高度随表观气速ug增加而增加,随开孔率降低而增加,当ug从0.04 m/s增加到0.24 m/s时,气垫层高度从0.01 m增加到0.06 m. 而局部气含率的径向分布与普通鼓泡塔相似,都随ug增加而增加,随径向位置r/R增加而减小;筛板的引入使局部气含率在轴向方向发生较大变化,ug=0.027 m/s时,筛板上下两侧的局部气含率均在0.05左右,但ug增加到0.11 m/s时,下侧气含率则普遍增加到0.3~0.35,而上侧则在0.25~0.3之间,下侧普遍比上侧气含率高.     

电感偶合等离子体原子发射光谱法测定氯化聚乙烯中的钙含量

建立了电感偶合等离子体原子发射光谱法分析氯化聚乙烯中钙含量的方法。采用标准曲线法分析氯化聚烯中钙含量,结果表明,钙在氯化聚乙烯样品中的平均加标回收率为98．62％,相对标准偏差小于1．29％,实验中钙的检出限（DL=3Sb／m）0．011ug／mL。     

Surface-mediated stereoselective hydrogenation of dienes over chromium subcarbonyls encaged in zeolite

Tricarbonyl chromium (0) species encaged in LiX or NaX was found to be highly efficient and stereoselective for the hydrogenation of butadiene at > 230 K. The selectivity to cis-2-butene depended both on the reaction temperature and butadiene pressure. The reaction mechanism is proposed, in which cis-2-butene is formed via (⁴-C₄H₆)Cr(CO)₃, while 1-butene via (²-C₄H₆)Cr(CO)₃ and (²-C₄H₆)₂Cr(CO)₃.     

Supported Cu Catalysts with Yttria-Doped Ceria for Steam Reforming of Methanol

The steam reforming of methanol was studied over Cu/Al₂O₃ catalysts with the addition of yttria-doped ceria (YDC). The YDC-modified catalysts were prepared by impregnating a -Al₂O₃ support with Y and Ce then with Cu. The addition of YDC drastically enhanced the activity of Cu/Al₂O₃ in the methanol reforming reaction. The enhanced activity was attributed to the increase of Cu⁺ species by YDC in the methanol reforming environment. However, the addition of YDC decreased the copper dispersion. The Cu dispersion could be enhanced by adding chromium oxide. The addition of YDC and Cr where Al₂O₃ was first impregnated with Cr then with YDC showed the most pronounced enhancement of the catalyst activity. At reaction temperatures of 200250 °C, the CO concentration in the products was smaller than 0.1%.     

铬酸钠碳化母液制备氢氧化铬工艺优化 及三氧化二铬粒度分布的影响

研究了利用铬酸钠碳化母液制备氢氧化铬工艺优化及三氧化二铬粒度分布的影响,主要考察了恒温温度、氢氧化铬洗涤方式对产品质量的影响;还考察了在固定煅烧条件下,铬酸钠含量对三氧化二铬颗粒形貌的影响以及铬酸钠碳化母液碳化率与三氧化二铬粒度分布的关系。结果表明,随着铬酸钠碳化母液碳化率的提升,Cr（Ⅵ）达到最大还原率时所需恒温温度下降,经过3次洗涤的氢氧化铬滤饼煅烧后铬酸钠质量分数为13%~15%,制备的三氧化二铬呈类球体,颗粒粒径均匀,洗涤烘干后各项参数指标均优于GB/T 20785—2006《氧化铬绿颜料》。通过增加原料碳化率,三氧化二铬颗粒的中位径D50随之增大,在碳化率为39.87%时制得的三氧化二铬中位径D50为 3.13 μm,粒度分布为典型的正态分布,其特征粒径值均符合高端氧化铬绿产品的技术要求。     

表面活性剂和硫酸盐还原菌去除污染土壤中的Cr6+

用表面活性剂和硫酸盐还原菌(SRB)淋洗Cr污染土壤,采用欧洲共同体参考物机构连续提取法分析淋洗前后土壤中铬化学形态和相对含量的变化. 结果表明,阴离子表面活性剂十二烷基苯磺酸钠和非离子表面活性剂Tween-80浓度分别为5.0, 0.01 g/L时,对土壤中Cr的淋洗效果最好,当土壤中Cr含量为200 mg/kg时,淋洗率分别为14.70%和24.74%,500 mg/kg时,淋洗率为35.99%和41.42%;反应体系中菌液量为10 mL时,淋洗18 h上清液中Cr6+转化率最大,分别为98.07%和94.73%;用表面活性剂和SRB共同处理Cr污染土壤,上清液中Cr6+可全部转化为Cr3+,未被淋洗出的Cr从较易被植物利用的可交换态转化为稳定态,主要以Cr2(CO3)3和Cr(OH)3存在于土壤中,达到了土壤环境质量标准.     

Origin of rate bistability in Mn–O/Al2O3 catalysts for carbon monoxide oxidation: role of the Jahn–Teller effect

Peculiarities in catalytic activity in carbon monoxide oxidation as well as some structure, electronic and magnetic properties of the three oxide catalysts, Mn³⁺–O/Al₂O₃ (1), Mn³⁺–O–Fe/Al₂O₃ (Mn-substituted spinel, 2) and -Fe₂O₃/Al₂O₃ (3), were studied by kinetic measurements and by Mössbauer spectroscopy. The catalysts 1 and 2 showed a kinetic bistability with a sharp transition towards more reactive state at 200°C (ignition point). In contrast, for catalyst 3, at 200–250°C, the behavior of reaction rate against temperature did not display noticeable hysteresis. On cooling the catalysts 1 and 2, extinction was observed at about 170 and 120°C, respectively, i.e., at 30–80°C lower than the corresponding ignition points. Proximity of activation energy for the high and low activity (15–19 kJ/mol) for both Mn-containing catalysts suggests an increase in the number of active sites at high temperature with no changes in the reaction mechanism. The considerable difference between Mn-containing catalysts 1, 2 and Fe-containing catalyst 3 may be caused by Jahn–Teller (JT) type distortions of the oxygen polyhedron around Mn³⁺. A significant spontaneous axial bond stretching within the local polyhedron seems to diminish Mn–O binding energy, facilitate the participation of surface oxygen species, O_S, in the oxidation of CO by a redox mechanism and promote oxygen vacancies at the surface that would cause considerable effect on the activity. An increase in the width of the counterclockwise hysteresis loop for the catalyst 2 compared to the catalyst 1 indicates that clusters of mixed spinel provide more active sites and more labile O_S species than clusters of the binary Mn oxide.     

化妆品中防腐剂7-乙基二环噁唑啉的气相色谱/质谱检测方法的研究

建立了化妆品中防腐剂7-乙基二环噁唑啉的气相色谱/质谱检测方法。采用Agilent DB-5MS石英弹性毛细管色谱柱,进样口温度250℃,柱温40℃,以15℃/min升至130℃,载气He,EI离子源,选择m/z55、83、113、143分别作为定量离子峰,并根据这4个抽出离子的峰面积比进行确证。结果表明,在此条件下7-乙基二环噁唑啉在0.1～10g/mL范围内的线性关系良好,检出限为1.75μg/kg,不同种类化妆品中7-乙基二环噁唑啉的加标回收率在72.1%～113.0%范围内,相对标准偏差（RSD）为1.92%～8.53%。此方法操作简便,分离速度快,检出限低,适用于对化妆品中防腐剂7-乙基二环噁唑啉的检测。