室温离子液体的热化学研究1.EMIES溶解热和Pitzer参数

在303．150K下,利用等温溶解反应量热计测定了不同浓度硫酸乙酯-1-甲基．3-乙基咪唑(EMIES)室温离子液体在水中的摩尔溶解热(△sHm),根据Pitzer理论得到了EMIES的无限稀释摩尔溶解热(△sHm^0)和Pitzer焓参数：βMX^(0)L,βMX(1)L和CMX^ФL,并计算了表观相对摩尔焓和溶质、溶剂的相对偏摩尔焓．     

硫酸预加热-容量法测定含氯地质样品中的有机碳

氯离子的存在影响有机碳的测定,导致结果偏高。采用硫酸预加热-重铬酸钾氧化的溶矿体系处理样品,在预加热过程中氯离子转化为氯化氢挥发,消除了氯离子的干扰;恒温电热板消解样品,避免了油浴对样品及环境的污染。通过对氯离子干扰定量实验、预加热温度、预加热时间等条件进行探讨,确定了最佳实验条件。在不影响有机碳与重铬酸钾正常反应的前提下,有效地消除了氯离子对有机碳测定的干扰,实现了含氯地质样品中有机碳的准确测定。通过土壤标准物质、海洋沉积物等含氯国家标准物质进行验证,相对误差小于1.5%,相对标准偏差小于7.3%,结果重现性好,准确度高,且操作简便,对环境无二次污染,易于推广应用。     

超微量铂丶铑连续催化极谱测定及其催化波机理的探讨

For simultaneous determination of ultramicro amounts of platinum and rhodium the optimum condition has been described as 1.5N H2SO4-1.2% NH4Cl-0.0012M (CH2)6N4-0.003% N2H4XH2SO4. Both platinum and rhodium produce hydrogen catalytic waves with peak potential at-1.03 V and - 1.27 V (vs. S. C. E.) and the peak height of differential wave in single-sweep polarograph is directly proportional to the concentration of the metals in the range from 0.05 ppb to 1.0 ppb for platinum and from 0.0025 ppb to 0.1ppb for rhodium, respectively. The influence of other platinum group metals and some base metals on the height of catalytic waves has been examined. It has been shown that the method is very selective. It is applied even at 200:1 or at 1:10 (Pt:Rh). The mechanism of the catalytic waves has been discussed. The catalytic waves of both platinum and rhodium are due to "surface catalytic wave of hydrogen". The wave of rhodium can be attributed to catalytic discharge of hydrogen ion by the complex (Rh(CH2O)2Cl4)-. One of the ligands, formaldehyde, is the product of hydrolysis of hexamethylenetetramine. The wave of plainum can be attributed to catalytic discharge of hydrogen ion by the complex (PtACl5)-, where a denotes intermediate product (a substance containing CH2=N group) formed during the hydrolysis of hexamethylenetetramine. The role of hydrazine sulfate in catalytic system has been shown. Hydzazine can react with formaldehyde to from (CH2=N)2 which promotes the growth of platinum catalytic wave and in this way the concentration of formaldehyde in the system can be controlled.     

LiCl/SO2-4-ZrO2催化剂上乙烷氧化脱氢制乙烯

 用辅以回流处理的两步法制备硫酸化氧化锆(SO2-4-ZrO2), 再用浸渍法制备Li质量含量为0.5%～15%的LiCl/SO2-4-ZrO2催化剂. 650 ℃时,在Li含量为15%的催化剂上,获得了90.6%的乙烷转化率、85.9%的乙烯选择性和77.8%的乙烯收率,在24 h的实验考察中,乙烯的收率一直保持在71%以上. 采用X射线粉末衍射、低温N2吸附、程序升温脱附和X射线光电子能谱等对催化剂的体相结构、比表面积、表面酸碱性和表面元素组成等进行了表征. 结果表明, LiCl的添加使催化剂中四方相ZrO2的含量降低,比表面积减小,表面酸性减弱,乙烷氧化脱氢催化性能明显提高,但ZrO2的体相结构对其催化性能没有明显影响. 随着反应时间的延长, LiCl慢慢流失,催化剂的乙烯选择性逐渐下降. 与未经回流处理制得的硫酸化二氧化锆相比,采用回流处理后的ZrO2制得的SO2-4-ZrO2具有较大的比表面积,单位质量的样品可负载更多的LiCl, 有利于延缓催化剂活性因LiCl流失而下降.     

甲苯胺蓝线扫极谱法测定硫酸软骨素

以电活性染料甲苯胺蓝(toluidine blue,TB)为生物探针,建立了一种线扫极谱法测生物多糖硫酸软骨素(chondroitin sulfate,CS)的电化学分析新方法。在pH5.0的Britton-Robinson(B-R)缓冲溶液中,TB在-0.04V(νs.SCE)处有一个灵敏的线性扫描二阶导数极谱还原峰。当在溶液中加入一定量的CS后,峰电流降低,但峰电位基本不变。这是由于两者在溶液中发生静电结合反应生成一种生物超分子复合物,导致其扩散系数降低,进而峰电流降低。利用峰电流降低建立了测定CS的电化学分析新方法。线性范围为6.0~30.0mg/L;检出限为1.9mg/L(3σ)。本方法成功应用于CS模拟样品的测定,利用电化学数据求解了结合比和结合常数。     

交沙霉素的光度分析研究

在一定条件下,稀H2SO4与交沙霉素(JSM)作用生成棕色配合物。该配合物的最大吸收波长为482 nm,表观摩尔吸光系数ε为8.55×103L.mol-1.cm-1,交沙霉素在一定浓度范围内遵从比耳定律,线性范围为0~16.5 mg/L。该法用于交沙霉素药剂中交沙霉素含量的测定,结果满意。