Comparison of the thermal decomposition behavior for members of the hydroxylamine family

In the present work the thermal stability of some members of the hydroxylamine family was studied using adiabatic calorimetry. The study included aqueous solutions of hydroxylamine free base, hydroxylamine hydrochloride, hydroxylamine sulfate, and hydroxylamine-o-sulfonic acid of concentrations typically used in industry. Also, the catalytic effect of metal surfaces of stainless steel, carbon steel, and titanium was studied. From the solutions studied HA is the most reactive with higher maximum temperature, pressure, non-condensable pressure, and lower time to maximum rate. HA maximum heat rate is at least ∼3 times higher than that of the other solutions studied, and the pressure generation rate is ∼13 times higher. All decompositions were catalyzed by stainless steel, but only HA was catalyzed significantly by titanium metal. Solid hydroxylamine hydrochloride, hydroxylamine sulfate, and hydroxylamine-o-sulfonic acid exhibited stability up to ∼60 °C. Hydroxylamine 100% was not studied because it is not readily available, is not used industrially, and is known to be unstable at room temperature. A violent reaction was measured for solid hydroxylamine sulfate that generated a heat rate >500 °C/min and pressure rate >5200 psia/min before the sample cell was completely destroyed by the generated pressure.     

Analysis of the iron state in iron containing vitamins and dietary supplements by Mössbauer spectroscopy

An analysis of iron in some commercial products of vitamins and dietary supplements containing ferrous fumarate, ferrous bisglycinate chelate (Ferrochel^®) and ferrous sulfate was made by Mössbauer spectroscopy. Various ferric and ferrous impurities were found. Two vitamin products contained major iron compounds that did not correspond to ferrous fumarate or ferrous bisglycinate chelate announced by the manufacturer.     

同时萃取-火焰原子吸收光度法测定锂盐及某些盐中锰、铬、铜、锌、镉、铁、钴、镍和铅

本文系用二乙基二硫代氨基甲酸二乙铵(DEDTC)/甲基异丁基甲酮(MIBK)pH5.7萃取体系,预浓缩以后,用原子吸收法在RbCl、 CsCl、 Sr(NO_3)_2、H_3BO_3、NH_4NO_3、NaBr、KI、Li_2CO_3、NaCl、KCl、CaCl_2、MgO、BaCl_2、KH_2pO_4、KNaC_4H_4O_6、C_6H_6O_7等盐类中测定痕量的锰、铬、铜、锌、镉、铁、钴、镍、铅等九个元素,其中应用于前面七个样品是我们提出的。检出限为1×10~(-4)％,九个元素的回收率在93～106％之间,相对标准偏差(n=7)为2.7％。     

有机改性剂胶束电动色谱分离测定去痛片等药物中的有效成分

运用有机改性胶束电动色谱，在ｐＨ＝８．０的磷酸盐和硼砂，十地基硫酸钠缓冲体系中加入乙腈１４％，操作电压１２ｋＶ时，咖啡因，苯巴比妥，扑热息痛，非那西丁，安替比林得到了很好分离。将本法用于实际药品的分析，其结果与标示量一致。     

CO和H2与Ni基催化剂的相互作用研究

用活性测试和程序升温动态红外光谱方法研究了ＣＯ和Ｈ２在Ｎｉ／Ａｌ２Ｏ３催化剂上的行为，并用量子化学从头算方法进行了模拟表征。结果表明，在较低温度下，ＣＯ在Ｎｉ／Ａｌ２Ｏ３上的线式吸附态和桥式吸附态相比，桥式对ＣＯ压力更敏感，而线式则对温度更敏感。     

有机共沉淀-石墨炉原子吸收光谱法测定高纯氧化镧、氧化钇中微量钴和镍

本文系用吡咯啶二硫代氨基甲酸铵(APDC)在0.3mol/L硝酸介质中共沉淀、石墨炉原子吸收法测定了高纯氧化镧、氧化钇中微量钴和镍、对于钴和镍的相对标准偏差分别为1.9～3.0％和3.9～4.1％;回收率分别为100～103％和95～100％;检出限分别为9.6×10~-(10)g和9.9×10~-(10)g。     

Crystal structure of 1-methyl-1,3,5,7-tetraazaadamantan-1-ium ammonium sulfate hydrate,a double salt containing puckered layers of hydrogen-bonded NH 4 + and SO 4 2− groups

The double salt [(CH₂)₆N₄CH₃](NH₄)SO₄·H₂O crystallizes in space groupP2₁/a, witha=12.994(2),b=6.319(1),c=15.082(2) Å, =93.78(2)^o, andZ=4. The structure was solved by the heavy-atom method and refined toR _F ²=0.051 for 2478 MoK data. The ammonium and sulfate ions are cross-linked by hydrogen bonds to form puckered layers disposed about the (001) family of planes. Each water molecule bridges a [(CH₂)₆N₄CH₃]⁺ ion and a sulfate group, so that the organic cations lying on both sides of a puckered layer have their methyl groups pointing inward and fitting into depressions. Supplementary Data relating to this article are deposited with the British Library as Supplementary Publication No. SUP 82063 (18 pages).Carried out, in part, under contract DE-AC02-76CH00016 with the U.S. Department of Energy, Office of Basic Energy Sciences.     

等离子炬-质谱技术测定白菜、萝卜、大豆、土壤中的痕量锰、钴、镍、铜、锌、砷、钼和锶

营养学家们已经确定了锰、钻、镍、铜、锌、砷、钼和锶等10多种人体所必需的痕量元素,它们对于维持人体的健康和长寿起着重要的生理作用。本文首次应用等离子炬-质谱技术测定了白菜、萝卜、大豆和土壤中这八种痕量元素的含量,并报告了它们的测定结果和标准偏差,其中土壤样品的测定值与参考值相比较,经 T 检验,两者之间在统计学上,没有显著性差异。实验证明该方法可对多种痕量元素同时定性、定量分析。操作简便、快速,灵敏度高;方法准确可靠,重现性好。为开展食品卫生学、营养学的研究,提供了更为先进的测试技术。     

镍含量对超细粒子负载型催化剂性能的影响——镍含量调变对NiO/SiO_2-TiO_2性能的影响

用溶胶－凝胶法，制备了不同镍含量的镍基超细粒子负载型催化剂前体ＮｉＯ／ＳｉＯ２－ＴｉＯ２．用氨溶－原子吸收分光光度法、ＴＰＲ技术，考察了活性组分氧化镍与载体之间的相互作用；通过ＩＲ、ＸＲＤ、ＴＥＭ－ＥＤＳ等手段，研究它们的物化性质、结构特征．用加压固定床连续流动微反装置上苯加氢生成环己烷的反应，对它们的催化性能进行关联．实验结果表明，采用溶胶－凝胶法制备得到的镍基超细粒子负载型催化剂体系中，活性组分氧化镍与载体之间有较强的相互作用，氧化镍形成簇状微晶，均匀地分散在载体氧化物之中．镍含量的调变，影响体系中氧化镍的微晶尺寸及其与载体的相互作用．催化剂在低镍含量（ＮｉＯ≥８％）时，即显出很高的活性，并具有优良的热稳定性及很宽的反应活性温度区域（１２０～２８０℃）．     

Ni-Cu/α-Al2O3催化剂上天然气转化制备低能耗合成氨原料气

制备了一系列Ｎｉ／Ｃｕ原子比不同的镍铜催化剂，测定了该系列催化剂对天然气、水蒸气和空气转化制备合成氨原料气的催化活性、选择性和稳定性。采用ＴＰＲ技术研究了催化剂的还原性能，以ＳＥＭ观察了催化剂的形貌。此外，还考察了活性组分负载量、铜添加量、催化剂制备方法以及温度和空速等反应条件的影响。结果表明，添加金属铜后，镍催化剂的活性和选择性均提高，随着铜添加量和添加方式的改变，反应活性亦有变化，以镍铜共浸，