电感耦合等离子体发射光谱同时测定生物环境和地质样品中的常量微量和痕量元素

研究了用ICP-AES同时测定大气漂尘中常量、微量和痕量元素,探讨了样品的前处理方法,盐酸、硝酸和硝酸-高氯酸对谱线强度的影响,研究了谱线之间的相互干扰情况和干扰校正,对其中大多数元素做了回收率试验。在折衷条件下应用本方法测定了美国NBS SRM1648城市颗粒物标准样品中的Ba、Ca、Cd、Co、Cu、K、Mg、Mn、Sr、Zn、Al、Fe、Li、Mo、Na、Ni、Sb、Ti、P、S、Sc和V,测定结果与标准值一致。     

Ca/Al物质的量比对Ni/CaO-Al_2O_3结构及其催化重整性能的影响

合成兼具催化、吸附性能的复合催化剂是实现CO_2吸附强化CH_4/H_2O重整制氢过程的关键。研究采用共沉淀法制备了一系列具有类水滑石结构前驱体的Ni/Ca O-Al_2O_3复合催化剂,考察了制备过程中Ca/Al物质的量比对复合催化剂结构及性能的影响。结果表明,Ca/Al物质的量比可调控活性组分Ni与载体之间的相互作用力,进而调变复合催化剂的比表面积和活性组分Ni的分散度。当Ca/Al物质的量比为3时,Ni与载体之间相互作用力适宜,复合催化剂具有最大的比表面积(12.9 m~2/g)和最高的Ni分散度(1.07%);该复合催化剂在CO_2吸附强化CH_4/H_2O重整制氢过程中可得到95%的H_2浓度和88%的CH_4转化率,循环10次后,H2浓度仍能保持在93%以上。     

不同月份栽培藏木香微量元素的含量测定及动态分析

采用火焰原子吸收光谱法对不同月份栽培藏木香中Cu、Zn、Fe、Mn、Ca、K、Mg和Na8种微量元素进行了分析测定。结果表明,在选定的测定条件下,栽培藏木香中各元素间相互干扰小,对测定无明显影响。方法的标准曲线线性关系良好(r=0.997 3~0.999 9),方法回收率(n=7)在97.5%~100.3%之间,RSD值(n=7)在1.16%~2.76%之间。栽培藏木香中K、Ca、Mg含量较高且不同月份微量元素含量有所不同,其中Zn、Cu、Mn含量基本稳定;K、Na、Ca、Mg、Fe等元素含量呈现较大幅度的变化趋势。研究结果为合理利用藏木香资源提供了可靠依据。     

ICP-AES中光谱干扰的计算机模拟——Ⅳ.不同分辨率条件下谱线互相干扰的模拟

本实验从仪器变宽角度出发,通过计算机模拟方法观察了不同分辨率条件下谱线之间的干扰情况。这种模拟既有助于样品分析前对仪器分光条件进行合理选择,又可为单色器的性能比较提供有益的参考依据。     

Synthesis of biodiesel from rapeseed oil catalyzed by Ca/A1 solid base

采用共沉淀法制备了Ca/Al复合氧化物固体碱催化剂,考察了沉淀剂种类、Ca/Al摩尔比、沉淀温度、溶液pH值、老化时间和焙烧温度等制备条件对其催化剂活性的影响.采用正交实验方法得到制备Ca/Al复合固体碱催化剂前躯体的最佳制备条件为,沉淀剂NaOH,Ca/Al摩尔比为3,沉淀温度为60℃,沉淀过程中pH值保持在10,在90℃老化18h.在该最优条件下制备的催化剂前驱体主要以Ca4Al2 O6(NO3)2· 10H2O晶相存在,在N2气保护下300℃焙烧2h后,催化剂形成高分散钙铝复合氧化物,且碱性强度达到26.5以上.在催化菜籽油和甲醇的酯交换反应中,菜籽油的转化率达到95％,脂肪酸甲酯的质量分数为95.9％.     

氮化硅粉中微量杂质金属的ICP-AES测定

本文论述了应用ICP-AES法测定氮化硅中微量杂质元素的分析技术,考察了样品处理及元素间相互干扰。采用板波模式超声雾化进样、去溶剂技术,ICP-AES法同时测定Si_3N_4中Al、Ca、Cr、Cu、Fe、Mg、Mn、Mo、Sr、Ti、V和Zr十二种杂质元素。各元素相对标准偏差为2.5～9.8%,回收率为84～108%。     

ICP–AES法测定稀土硅铁球化剂和孕育剂中钙、镁、铝、锰、镧、铈

建立了电感耦合等离子体原子发射光谱法(ICP–AES)测定稀土硅铁球化剂和孕育剂中Ca,Mg,Al,Mn,La,Ce等元素含量的方法。通过基体匹配消除了铁基体的干扰,Ca,Mg,Al,Mn,La,Ce的分析谱线分别为317.933,279.553,394.401,257.610,333.749,456.236 nm。各元素标准曲线的线性相关系数均在0.999以上,检出限在0.000 1%~0.000 4%之间。方法的加标回收率为99.4%~102.8%,测定结果的相对标准偏差均小于3%(n=11)。用该方法测定标准样品,测定结果与认证值相吻合。该法适用于稀土硅铁球化剂和孕育剂中钙、镁、铝、锰、镧、铈的测定。     

等离子发射光谱法测定碳化硼颗粒增强铝基复合材料中6种元素

采用等离子发射光谱法同时测定碳化硼颗粒增强铝基复合材料中Al,Si,B,Mg,Cu,Fe等元素的含量。分析了各元素之间以及基体的光谱谱线相互干扰情况,对标准溶液采取与样品大致相同的基体匹配方式,消除了基体干扰,使测定结果更加准确。     

丙酮酸在悬汞电极上的电化学行为及其与Al髥的相互作用

研究了酸性、中性、碱性范围内丙酮酸在悬汞电极上的电化学行为,对实验条件进行了优化,在最佳条件下丙酮酸的还原峰电流和浓度有良好的线性关系。同时在不同pH值条件下研究了Al髥和丙酮酸的相互作用,结果表明,不同pH值范围内Al髥和丙酮酸的相互作用均为弱作用,弱作用强度为酸性>碱性>中性。这种作用强度的差别可能来自于不同条件下Al髥的存在形态不同。     

野生唐古特大黄矿物元素含量特征

对比青海果洛境内野生唐古特大黄中10种矿物质元素含量特征,用原子吸收光谱法分析了其常量元素K、 Na、 Ca、 Mg 、 P及微量元素Cu、 Zn、 Fe、 Mn、 Al含量。结果表明,唐古特大黄根部与其土壤环境呈现出不同的矿物质元素含量特征,植物中Na、 Ca和P总体表现出富集趋势。矿物质元素含量在不同居群的差异,提示在不同的生境条件下唐古特大黄对矿物质元素采取选择性吸收。     

从基体干扰角度进行电感耦合等离子体原子发射光谱分析条件的优化

本文探讨了不同分析条件下基体干扰效应的分布规律,从消除基体干扰效应角度对ICP-AES操作条件的优化进行了讨论。结果表明,在一般分析条件下,典型基体元素的零干扰点主要出现于10～15mm的观察区域。在此区间仔细选择观察高度,同时结合入射功率、载气流量的调整及加入基体缓冲剂,可以将基体的影响减至最小。     

Spectral interference on the emission of sulphur I 180.73 nm in an inductively coupled plasma

Spectral interferences on the S I 180.73 nm emission line by Al, Ca, Mn and Fe in an inductively coupled plasma are described. The critical concentration ratios for Ca, Mn, Al and Fe with respect to S are 90, 300, 3300 and 25000 respectively (full width at half maximum = 0.0075 nm). Intensity measurements at various observation zones in the plasma show that the spectral interference from Ca and Mn emission line overlaps may be reduced by observing the S emission at a lower observation height in the plasma.     

Systematic investigation of aluminium interferences with the alkaline earths in flame atomic absorption spectrometry

Summary Aluminium interferes with the absorption of Mg and Ca in the air-acetylene flame to such an extent that the corresponding absorbances may fall even to zero. This well-known chemical interference can be overcome with the nitrous oxide-acetylene flame, completely in the case of Mg, however only to a restricted extent in the case of Ca. Mg and Ca with concentrations of the AAS-working range in aqueous solutions and Cl^– or NO ₃ ^– as anions (in an aqueous HCl or HNO₃ matrix, respectively), were determined in the air-acetylene flame with continuously rising Al portions and with (or without) 0.25% Cs as radiation buffer, in order to quantify the degree of these interferences. The same was done to evaluate the extent of the suppression of those interference when using a releaser or protector reagent in both the air-acetylene and the nitrous oxide-acetylene flame. After the decrease of absorption in the air-acetylene flame by forming thermally stable Mg or Ca aluminates, a rapid increase (positive interference) occurs unexpectedly in the presence of Cl^–±Cs and with further rising Al contents. This effect still appears for Ca also in the hotter nitrous oxideacetylene flame, however, only in a restricted extent. In the air-acetylene flame the undisturbed absorptions for Mg and Ca (i.e. the starting data without Al) are nearly reached again within the range of the positive interference. This supports the assumption that in consequence of a continuous equilibrium change in the flame because of the rising Al content and in the presence of Cl^– and ±Cs the formation of only pure Al oxides now generates the release of Mg and Ca (instead of the thermally stable aluminates in the beginning). In the air-acetylene flame interferences of 1000 mg/l Al are completely removed by an addition of 1% releaser-La, when measuring up to 0.2 mg/l Mg and up to 4 mg/l Ca. The extent of releasing Mg and Ca is effective only up to that Al concentration range which leads to the absorption maximum of Mg and Ca. In the nitrous oxideacetylene flame 5000 mg/l Al are compensated when determining up to 1 mg/l Mg. In the case of Ca, which is detected up to 4 mg/l, interferences of 1000 mg/l Al are only avoided by using the nitrous oxide acetylene flame together with 1% releaser-La. The excellent sensitivity of Ca in this flame (in contrast to the air-acetylene flame) permits a strong dilution, lowering thereby the interfering Al concentration, too. For Mg the same option is valid because of its high sensitivity in the air-acetylene flame.     

塞曼石墨炉原子吸收光谱法直接测定血液中痕量铝

采用偏振塞曼原子吸收法，以Ｃａ作基体改进剂，注入热解涂层石墨管中，直接测定用ＯＰ溶液稀释血液样品中的痕量铝，有效地消除了血液基体的干扰，克服了铝的记忆效应，从而提高了方法的测定灵敏度、重现性和准确度。     

Multi-elemental profile patterns during the life cycle stage of the soybean Part 1. Determination of representative elements, Na, Mg, Al, K and Ca

We present Na, Mg, Al, K and Ca profiles, determined by neutron activationanalysis (NAA) in a soybean plant during its life cycle in water culture.The concentrations of Mg and Ca in leaves were higher than the other tissuesduring the developmental stage of a plant. The concentration of K was relativelyuniform within a plant. When a plant was treated with V, element uptake amount,especially Mg, K and Ca, was decreased throughout the life cycle. Vanadiumtreatment also induced low concentration of Mg and K in roots.     

光度络合滴定(Ⅱ)——微量铝的滴定(以丙二酸隐蔽铝)

本文报导了在室温下以DCTA定量络合铝,并使用DCTA-丙二酸隐蔽法分光光度滴定微量铝的方法。本法的选择性极好。利用这种方法测定了石英石、石英砂、石灰石、白云石和自来水中的微量铝,得到了满意的结果。     

Study on the excitation mechanism 1. Non-Boltzmann–Saha distributions in the inductively coupled plasma

This work has further shown that the collisional–radiative multi-level model for the analyte atom and ion could be approximated by the step-wise series model. The non-Boltzmann and non-Saha factors of Ca for 48 levels corresponding to radiative decay, radiative recombination, Penning ionization and absorption processes, respectively, as well as to their mutual processes occurring at the axial channel of inductively coupled plasma and at an observation height of 15 mm above the load coil, were calculated. It was found that the high level relative to low level is over populated.     

Electrothermal behavior of sodium,potassium, calcium and magnesium in a tungsten coil atomizer and review of interfering effects

The electrothermal behavior of Na, K, Ca and Mg in a 150-W tungsten coil atomizer was investigated in order to gather information about the atomization processes and the underlying factors responsible for chemical interferences of them on atomization of Al, Ba, Cd, Co, Cr, Pb and Yb. The interference effects were discussed considering the thermal stability of the species that could be formed in the condensed phase, the effect of protective gas composition in the atomization process and the pyrolysis temperature curves. Ca is the most serious interferent due to its high thermal stability (up to 1600°C) and to the possibility of double oxides formation. As hydrogen is decisive for the atomization of Na, K, Ca and Mg, some interference processes caused by these elements seem to be related to the competition towards hydrogen present in the protective gas composition. The knowledge of the correct temperature of the tungsten coil surface shows that most strategies for overcoming interferences based on chemical modifiers will fail for Cd and Pb, because tungsten acts as a natural permanent chemical modifier. It seems that in many applications previous separation and masking will be necessary.     

交流示波极谱滴定的研究(Ⅳ)——大量镁存在下用EGTA滴定钙

将交流示波极谱滴定应用于大量镁存在下钙的EGTA滴定。Ca:Mg的比例可达1:40,Fe、Ti、Al、Mn、Pb等杂质存在时,不需要另加其它掩蔽剂。此法优点:仪器简单、方法快速、终点明确、准确度好。用于石灰岩矿样分析,得到满意的结果。