凝胶渗透色谱法测定聚丙烯腈共聚物分子量中宽分布校正法的应用

应用宽分布校正法对凝胶渗透色谱(GPC)进行了校正，将校正曲线用于聚丙烯腈(PAN)共聚物分子量的计算。对扣除色谱峰扩展效应前后的测试结果与乌氏粘度法测得的数据进行比较。结果表明，应用宽分布校正法时，必须扣除色谱峰扩展效应，才能得到较为准确的测试结果。     

Studies on Natural CXN Zeolite： Modification, Framework De-alumination and Ion-exchange

A natural CXN zeolite (stilbite, type code-STI) discovered in China was modified with NH4^ exchange by using ammonium salt and calcinations (procedure Ⅰ), or with NH4 exchange followed by treatment with acid (procedure Ⅱ). The coordination state of Si and A1 atoms in the framework, the property of ion exchange, and the adsorption of the H-STI zeolite samples prepared by different modification procedure were investigated with XRD,EDX,^29Si and ^27Al MAS NMR, Ag^ ion exchange and Ne adsorption. The results of the investigations indicate that different procedure of the modification made variety on the distribution of the framework Si atoms and A1 atoms,the content of non-framework aluminum, and the blocking channels and the shielding effect to the positions of the exchangeable cations. The H-STI zeolite prepared by the procedure Ⅱ possesses high ion exchange capacity, open and perfect pore system, and high thermal stability.     

2-氨基-3-硝基吡啶和2-氨基-5-硝基吡啶的CI-MS-MS分析

二氨基-3-硝基吡啶和2_氨基-5-硝基吡啶的EI—MS质谱图接近，单纯通过Ⅱ-MS质谱图较难区分这两种异构体，作者以甲烷为反应气对2-氨基-3-硝基吡啶和2-氨基-5-硝基吡啶进行化学电离，并利用离子阱质谱的串联质谱技术在离子阱内以He作碰撞气进行碰撞诱导裂解，所得的CI—MS—MS质谱图表明，两者之间存在明显的差别，可用于2-氨基-3-硝基吡啶和2-氨基一5一硝基吡啶的鉴别。     

铁氰化镍/银复合无机膜修饰电极对肼的催化氧化作用

在含有Ag+、Ni2+的胶体混合溶液中,多次循环扫描在电极表面形成复合无机膜(Ag/NiCHF),此复合膜修饰电极对肼有显著的催化氧化作用。N2H4的浓度在5.0×10-6～6.0×10-3mol/L范围内与电流呈线性关系,检出限达到1.0×10-6mol/L。该电极已成功的用于水样中肼的测定。     

CeO2添加剂对等离子ZrO2涂层抗热震性的影响

在ZrO2陶瓷涂层中加入适量的CeO2，使陶瓷涂层的抗热震性能得到提高，这主要是由于CeO2的加入，涂层的微小孔隙增加、涂层产生细微的网状裂纹，增加了微裂纹密度，从而降低了徐层的弹性模量，释放了涂层中的应力，提高了涂层的裂纹失稳扩展时的临界温差ΔTc，并可阻止裂纹沿单方向的快速扩展，使涂层的抗热震起裂性能和抗热震失效能力得到提高。其中，CeO2加入量为9％效果最佳，过量加入CeO2，会过早地促进裂纹的扩展、断裂，不利于提高涂层的抗热震性能。     

高效液相色谱法紫外检测人尿中美托洛尔和α－羟基美托洛尔

 用高效液相色谱法紫外检测人尿中美托洛尔（Ｍ）和α－羟基美托洛尔（ＨＭ）浓度，采用ＳｐｈｅｒｉｓｏｒｂＯＤＳ１２５ｍｍ×４ｍｍｉ．ｄ．（５μｍ）色谱柱，甲醇：水：冰乙酸：三乙胺（７０：３０：０：１２：０：０３）为流动相，紫外检测波长为２１５ｎｍ。Ｍ和ＨＭ的平均回收率分别为９８．５／和９９．８％，日内和日间变异系数均小于４．５％。方法快速、简便、灵敏，可用于药物氧化分型研究。     

用混合床离子色谱柱同时测定阴阳离子

将阴离子交换树脂和阳离子交换换树脂混合后填充在一根色谱柱中，即所谓阴阳离子混合床柱。研究了阴阳离子在此混合柱上的保留行为并探讨了其保留机理。     

生晒参、全须生晒参中19种有机氯残留农药的毛细管气相色谱测定

建立了生晒参、全须生晒参中19种有机氯农药残留的毛细管气相色谱分析方法。对样品中六六六的4种异构体、滴滴涕的5种异构体、四氯苯胺、六氯苯、五氯硝基苯、七氯、五氯苯胺、艾氏剂、百菌清、环氧七氯、狄氏剂及异狄氏剂共19种有机氯农药的残留量进行了测定。以石油醚-丙酮混合物作为提取剂,样品采用索氏提取,提取液用弗罗里硅土柱层析净化。采用OV-1701石英毛细管气相色谱柱分离样品,ECD检测器进行检测。在3个水平添加时的回收率(n=5)分别为75.7%~96.1%、78.8%~111.6%和81.7%~115·2%;相对标准偏差分别为2.4%~10.6%、2.1%~9.8%和1.4~10.0%。方法用于生晒参和全须生晒参样品中农药残留的测定,结果满意。     

Vibrational Spectroscopic Study on Ion Solvation and Association of Lithium Perchlorate in 4-Methoxymethyl-ethylene Carbonate

Solvation interaction and ion association in solutions of lithium perchlorate/4-methoxymethyl-ethylene carbonate （MEC） have been studied by using Infrared and Raman spectra as a function of concentration of lithium perchlorate. The splitting of ring deformation band and ring ether asymmetric stretching band, and the change of carbonyl stretching band suggest that there should be a strong interaction between Li^＋ and the solvent molecules, and the site of solvation should be the oxygen atom of carbonyl group. The apparent solvation number of Li^＋ was calculated by using band fitting technique. The solvation number was decreased from 3.3 to 1.1 with increasing the concentration of LiClO4/MEC solutions. On the other hand, the band fitting for the ClO4^- band revealed the presence of contact ion pair, and free ClO4^- anion in the concentrated solutions.     

嘌呤衍生物在葫芦［6］脲单轮烷键合固定相上的色谱行为

在反相和正相色谱模式下,研究了几种嘌呤衍生物在葫芦［6］脲单轮烷键合硅胶固定相上的高效液相色谱行为,并在反相模式下与ODS固定相进行了比较,考察了流动相中甲醇含量、流动相pH值和离子强度对嘌呤化合物保留的影响。研究结果表明:在反相模式下,嘌呤化合物与葫芦［6］脲单轮烷键合相之间存在多种相互作用,除疏水作用外,分离过程中还存在与ODS不同的色谱分离机制。在正相条件下,多作用力的色谱分离机制同样存在。葫芦［6］脲单轮烷键合相与溶质之间存在疏水、氢键、π-π和偶极-偶极等多种作用力,协同作用提高了固定相对嘌呤化合物的分离选择性。