加芯毛细管填充柱的理论研究

从速率方程和柱压降两个方面对加芯毛细管填充柱的柱效和渗透性进行了探讨，并详细讨论了柱直径、芯直径、芯根数和柱压降的关系。综合考虑柱压降、板高和拉制柱子时颗粒在柱内的镶嵌状况可知最佳柱型是３芯的毛细管填充柱。     

新型微填充柱-毛细管柱二维色谱系统的理论研究(Ⅱ)──双柱条件对柱效的影响

从色谱动力学角度探讨了改变微填充柱-毛细管柱二维色谱系统中双柱条件对柱效的影响规律,进一步证实了短填充柱接长毛细管柱及高预柱柱温、快预柱载气线速有利于提高双柱系统柱效的结论;同时,通过对主柱柱温、载气线速及柱间分流比的讨论,从理论和实验上也证实了相对较低的主柱柱温、较慢主柱线速以及稍大的分流比有益于柱效利用率的提高。     

加芯毛细管填充柱的理论研究

 从速率方程和柱压降两个方面对加芯毛细管填充柱的柱效和渗透性进行了探讨，并详细讨论了柱直径、芯直径、芯根数和柱压降的关系。综合考虑柱压降、板高和拉制柱子时颗粒在柱内的镶嵌状况可知最佳柱型是３芯的毛细管填充柱。     

干凝胶无机整体柱的制备及评价

以硅酸钾为硅源,甲酰胺为催化剂在毛细管内原位聚合形成干凝胶柱,制备了一系列致密度不同的整体柱。该法在柱制备及高温干燥过程中不会发生柱床断裂和塌陷现象,此特点明显优于以烷氧基硅烷为前驱体制备无机整体柱的方法。考察了不同模数硅酸钾对整体柱柱床结构的影响,用扫描电镜(SEM)和氮吸附法对整体柱结构进行了表征,考察了整体柱柱压与流速的关系;对整体柱进行十八烷基修饰后,测定了反相整体柱(C18整体柱)对蒽的柱效,通过考察甲苯在该柱上的突破曲线,获得了其对甲苯的柱容量。结果显示该整体柱柱床刚性好,在高温、高柱压、高流速时柱床能保持其物理结构的稳定性,对蒽的柱效达到41400理论塔板/m,对甲苯的柱容量为61 ng。     

Alltech集束毛细管柱和常规毛细管柱的比较

对集束毛细管气相色谱柱的色谱性能,如流速对柱效的影响、柱温对柱效的影响、柱容量等进行了考察,并将其对典型火炸药成分ＤＮＴ,ＴＮＴ的分离与常规毛细管气相色谱柱进行了比较。结果表明,集束毛细管气相色谱柱综合了填充柱与石英毛细管气相色谱柱之优点,弥补了二者的不足,是一种柱容量较大且分离效能好、可以在高载气流速下操作的新型气相色谱柱。     

溶胶-凝胶法制备用于分离极性有机化合物的毛细管气相柱

 采用溶胶 凝胶法制备了用于分离有机极性化合物的毛细管气相柱 ,其制备工艺简单 ,制柱时间较传统工艺大为缩短。该柱涂层与毛细管内壁间形成的化学键使得其热稳定性好。游离的脂肪酸、有机碱可直接在该柱上得到很好的分离 ,其他极性化合物也在该柱上得到极好的分离。该类柱不仅在同一柱上显示了良好的分离重复性 ,而且不同柱间在容量因子、柱效、对称性及姆氏常数上也显示了良好的重复性。     

开管离子色谱柱的制备与表征

近年来,开管离子色谱(OTIC)的研究已取得重大进展,尤其是兼容OH^-淋洗液的OTIC柱的成功研制使OTIC梯度洗脱得以实现。该文介绍了各种OTIC柱的制备和表征方法,涵盖早期的二氧化硅开管柱和新近出现的有机聚合物基质开管柱,对静电乳胶附聚的OTIC柱的一系列表征方法进行了系统阐述,包括开管柱柱容量的实验测定和理论计算方法、固定相相同时填充柱与开管柱之间的联系、柱效改善方法以及开管柱均一性表征等。     

原位合成分子筛气-液改性毛细管柱的制备与评价

 用原位合成方法成功地制备了一类新型NaA分子筛毛细管柱 ,与传统柱型相比 ,原位合成柱的分子筛层更加均匀与致密、分离效果更佳。在此柱上涂敷不同极性的固定液制备了一类新型气 液分子筛改性SCOT柱 ,测试表明该柱型分离效果较佳、热稳定性好 ,其中超短柱及大口径柱的成功应用更显示该柱型具有很高的实际应用价值 ,值得推广。     

高效制备液相色谱柱技术的研究进展

本文概述了高效制备液相色谱柱的柱型结构、填料以及柱填充方法等研究的最新进展,讨论了制备柱与分析柱的不同特征,对目前普遍使用的压缩型制备柱的类型、结构及填充方法作了较为全面的评述,总结比较了工业化制备色谱填料不同于分析色谱填料的特点,探讨了高效制备液相色谱柱技术的应用和发展前景.     

基于微机电系统的微型气相色谱柱研究进展

气相色谱柱是气相色谱仪的关键部件,主要用于混合气体组分的分离。与传统气相色谱柱相比,基于微机电系统（MEMS）技术设计制作的微型气相色谱柱具有重量轻、体积小、功耗低、分离快速等优点,便于集成到便携式气相色谱仪中,适应了目前气相色谱仪微型化的发展趋势。该文综述了MEMS微型气相色谱柱的研究进展,首先阐述了MEMS微型气相色谱柱理论基础,随后对MEMS微型气相色谱柱沟道布局及柱内结构、固定相支撑层及固定相制备等方面进行了综述,最后对其发展趋势进行了展望。     

Theoretical basis for multielement analysis by coherent forward scattering atomic spectroscopy

A theoretical basis for multielement analysis by coherent forward scattering atomic spectroscopy is discussed. Forward scattering spectra are calculated for various atomic transitions in the Faraday and Voigt configurations. It is shown that the multielement capability of forward scattering stems from spectral response to continuum radiation. Comparison is made with the Zeeman atomic absorption method. An experimental result with a xenon arc lamp is also given.     

The yields of photonuclear reactions for multielement photon-activation analysis

A comprehensive study on the yields of photonuclear reactions of various types has been performed, and sensitivities and the effects of interferences in multielement photon-activation analysis have been evaluated by bremsstrahlung activation of many elements with maximum energies ranging from 30 to 60 MeV. The applicability and reliability of the method were demonstrated by analyzing standard round-robin samples and then by presenting the elemental abundances in several geological, biological and environmental materials. The method was almost insensitive to matrix effects and was assessed to be promising for nondestructive multielement determination of the materials of wide variety, giving good reproducible results for 20 or more elements.     

Neutron activation analysis without multielement standards

A physical approach is described for instrumental multielement activation analysis with whole neutron spectrum (without Cd-cover) using the monostandard (single comparator) method. To test the capabiliteries of this method, 15 samples representing different Egyptian granite rocks were analyzed. As many as 21 trace elements beside Fe, K and Na were determined. Calculation of the experimental data has been done using the Gamma-Monostandard Analysis program with the Commodore Computer available at the Institute of Radiochemistry at Garching near München. The accuracy of the method for nondestructive multielement analysis agrees within 3% with the relative method using multielement standards.     

Determination of trace levels of metal ions in water samples by inductively coupled plasma mass spectrometry after on-line preconcentration on SO3-oxine CM-cellulose

Summary A method utilizing a miniature chelated ion-exchanger column of SO₃-oxine CM-cellulose has been developed to increase the sensitivity for multielement measurements by inductively coupled plasma mass spectrometry (ICP-MS). This matrix/analyte separation and preconcentration technique has been used to preconcentrate Mn, Co, Ni, Cu, Cd, and Pb from natural water samples. The multielement detection limits are in the low ppt (pg/mL) range. This FIA-ICP-MS method has been applied to the determination of various trace levels of metal ions in riverine reference material SLRS-2 and open ocean seawater reference material NASS-3.     

Multielement photon activation analysis of biological materials.

A non-destructive photon activation procedure with 30-MeV bremsstrahlung followed by high-resolution γ-spectrometry is proposed for multielement analysis of biological materials. The materials tested were the NBS SRM Orchard Leaves and Bovine Liver, Bowen′s kale and Kentucky 1R1 tobacco standards. Simultaneous irradiation of the sample with synthetic multielement standards containing 25 elements showed that up to 12 elements can be determined in a single sample. The method is quite simple and gives good reproducible results. Agreement of the results with published data is excellent.     

Simultaneous determination of lead, nickel, tin and copper in aluminium-base alloys using slurry sampling by electrical discharge and multielement ETAAS

The simultaneous multielement determination of Pb, Sn, Ni and Cu in aluminium alloys by electrothermal atomic absorption spectrometry (ETAAS) was performed by a quick method using slurry sampling. The metallic colloidal slurries were obtained by an electrical discharge operated in liquid medium. In this work, the effects of aluminium were evaluated and the results show that it causes a strong retention of Pb, Ni and Cu at low pyrolysis temperatures which is overcome by employing high pyrolysis temperatures. Aluminium also significantly improves the thermal stabilisation of Pb and Sn, it being possible to reach pyrolysis temperatures of 1100 and 1300 °C, respectively. Such stabilisation indicates that the performance of aluminium as a matrix modifier for Pb is better than that obtained using phosphate and magnesium nitrate without substantial changes of the figures of merit. The effects of aluminium on the atomisation characteristics of the elements and those coming from the simultaneous multielement determination on the figures of merit of the elements are also discussed. In this work, a calibration procedure involving a matrix matching method with aqueous aluminium standards is proposed as a simple and efficient way to solve the inconveniences originated by the aluminium matrix. The proposed method was applied to the simultaneous multielement determination of several aluminium-base alloy standards giving results well within the recommended values.     

Transport efficiencies and analytical determinations with electrothermal vaporization employing electrostatic precipitation and electrothermal atomic spectroscopy

Analyte transport efficiencies of solid as well as liquid samples were determined for electrothermal vaporization (ETV). A graphite furnace of the boat-in-tube type was employed for ETV. The generated aerosol was transported by an argon flow via a tubing into an external precipitator and deposited on a L’vov platform with a corona-like discharge. The sample on the secondary platform was analysed with a laboratory-constructed coherent forward scattering multielement spectrometer. For determining the analyte transport efficiencies, the comparative measurements were carried out with standard solutions dosed directly on the platform in the spectrometer furnace. The simultaneously investigated elements were Cu, Fe and Mn in the standard reference material BCR CRM 189 wholemeal flour and in a multielement standard solution containing approximately the same element ratio as certified for the solid sample. ETV boat-to-L’vov platform transport efficiencies of approximately 19% for Cu, 24% for Fe and 19% for Mn were calculated for both solid samples and multielement standard solutions. Cu, Fe and Mn in wholemeal flour were determined simultaneously by calibrating against aqueous multielement standard solutions injected into the boat as well as by the standard addition method. The results agree satisfactorily, the deviations from the certified values are below 10% and the relative standard deviations are typically 5–8%. The limits of detection are 250 pg for Cu (λ=324.8 nm), 230 pg for Fe (λ=248.3 nm) and 90 pg for Mn (λ=279.8 nm), loaded into the ETV boat.     

计算原子吸收分光光度法多元素同时测定

本文研究了用计算原子吸收分光光度法进行多元素同时测定的方法：利用火焰原子吸收法中的化学干扰效应．建立相应的关系函数，以标准增量法测定，非线性最小二乘法迭代求解，同时计算出主测素和干扰元素的含量，从而实现了多元素的同时测定。     

Instrumentation for simultaneous multielement atomic absorption spectrometry with graphite furnace atomization

Graphite furnace-atomic absorption spectrometry (GF-AAS) is restricted to the determination of 4 to 6 elements simultaneously due to the limitations of hollow cathode lamps. However, a consideration of prototype continuum source instruments and recent advances in the fields of spectrometer and detector technology suggests that a multielement GF-AAS instrument, with the multielement versatility associated with atomic emission spectrometry, is possible. Such a multielement instrument would employ a continuum source and provide 1.) multielement determinations for 30 to 40 elements, 2.) wavelength and time integrated absorbance measurements which are independent of the source width, 3.) detection limits comparable to line source AAS with the potential for another order of magnitude improvement using atomization at elevated pressures, 4.) extended calibration ranges limited only by the memory of the atomizer, and 5.) high resolution inspection of the spectra surrounding the analytical wavelength. Such an instrument could provide figures of merit comparable to inductively coupled plasma-mass spectrometer with considerably less complexity.     

Monostandard activation analysis: Evaluation of the method and its accuracy

The different approaches of the monostandard activation analysis are evaluated critically in order to put them into a common formulation. The nuclear data relevant to the method, which are selected and verified by experiment, are presented for general application. The accuracy of the method for multielement analysis is discussed by comparing the analytical results of the various reference materials from different methods and laboratories with those from monostandard activation analysis.