分析裂化气中0.5ppm～1%含量的杂质烃

本文介绍了一种分析裂化气中杂质烃的方法。所建分析系统由填充玻璃毛细管柱和填充预柱各一根、阀和FID各一个组成。采用一次进样、外标法定量,约30分钟即可完成测定裂化气中低至0.5ppm含量的痕量C_2～C_4炔和二烯。方法适用围范至少是0.5ppm～1%。当样品含量为1～5 ppm时,相对标准偏差小于50%。     

腐霉利及其代谢物(TBPC)在土壤中残留分析方法标准研究

研究了腐霉利及其代谢物(TBPC)在土壤中残留分析方法.样品以丙酮提取,加入CHCl3,分离出有机相,加入少量正癸醇,旋转蒸发近干,前处理后的样品上机检测,其中腐霉利采用FPD中的S检测器,其代谢物TBPC采用FID监测器.腐霉利的最小检测量为0.01 ng,代谢物(TBPC)的最小检测量为0.03ng.用优化后的方法在土壤中分别进行添加回收实验,得到的腐霉利平均添加回收率:添加0.1 ppm时为79.4%,添加1.0 ppm时为81.3%,代谢物(TBPC)平均添加回收率:添加0.1 ppm时为85.5%,添加1.0 ppm时82.7%.该方法达到农药残留分析的要求.     

特殊钢中稀土变质夹杂物行为研究

通过加入稀土金属(Ce),研究不同稀土含量对变质夹杂物的影响。发现在洁净度较高的A l脱氧特殊钢中稀土能够使氧化铝、硫化锰夹杂变质并能形成硬度较低的铝酸稀土夹杂物。研究结果表明:当稀土含量Ce15 ppm时,钢中没有稀土夹杂物;当15 ppm≤Ce≤140 ppm时,能够生成稀土铝氧化物和稀土硫氧化物夹杂物;当Ce140 ppm时,夹杂物进一步转变为稀土铝氧化物和稀土氧硫化物的复合夹杂物,并有部分稀土氧硫化物和稀土硫化物,夹杂物的尺寸也随着增大。热力学分析计算表明:在[O],[S]含量较低的前提下,Ce变质A l2O3所需的条件是aCe.aA-l1=0.145,当[A l%]=0.01~0.03时,对应溶解的稀土含量[Ce]=22~67 ppm。     

二氧化碳的络合固定

<正> 近代工业迅速发展的结果,使燃料消耗量剧增,燃料消耗过程放出大量的二氧化碳,加上大量砍伐吸收二氧化碳的树木,使得地球上大气中二氧化碳含量逐日增加。据报导,十九世纪末大气中二氧化碳含量为295ppm,现在大气中二氧化碳含量已达320ppm若这样下去,下世纪大气中二氧化碳含量将超过400ppm,这样将使地球表面和大气层辐射的一些长波光线难以穿透,热量不易散失,结果将使地球表面气温逐年上升。     

具有抗硫性能的CO氧化复合氧化物催化剂

SO_2对钙铁矿型及其它氧化物型的CO氧化催化剂是一种强烈毒物,而汽车尾气中的SO_2含量一般为10—20ppm.因此,这类催化剂对SO_2的敏感性是其实际应用的一     

气相色谱法测定柑桔中甲基托布津残留量

本文根据甲基托布津在一定温度下,分解放出含硫化合物的特点,建立了用气相色谱法直接测定甲基托布津残留量的方法。用丙酮提取样品,二氯甲烷液液分配净化,用带FPD气相色谱仪检测。在5～30ng范围内呈良好的线性关系。方法最低检测浓度为0.02ppm,回收率为87.3～98.2%,变异系数为2.0%。     

丁二烯中痕量气体杂质的分析

本文提出一简便的气相色谱法,用于分析丁二烯中含2-100ppm的气体杂质.采用高灵敏度钨丝热导池作鉴定器,用5埃分子筛作吸附剂而分离H_2,O_2,N_2,CO,CH_4.用丁酮酸乙酯为固定液使CO_2和所有气体烃分离.又讨论用热导池作鉴定器时,影响气相色谱法最小鉴知量的各种因素.这分析方法的最小鉴知量为0.02微升H_2,0.1微升O_2,0.3微升N_2,0.4微升CO,0.4微升CH_4,0.3微升CO_2,0.2-0.9微升气体烃.分析氢时的取样10毫升,分析O_2,N_2,CO,CH_4时50毫升,分析CO_2和气体烃时为13毫升.此时最小鉴知浓度分别为2ppm H_2,2ppm O_2,6ppm N_2,8ppm CO或CH_4,20ppm CO_2和14-74ppm气体烃,     

原子捕集原子吸收光谱法测定银的研究

West等人用硅管在空气-乙炔焰中捕集银2分钟,测得银的特征浓度为9×10~(-4)ppm,比常规火焰原子吸收法的灵敏度提高40倍。孙汉文用不锈钢管在空气-乙炔焰中捕集0.005ppm银10分钟,测得银的特征浓度为4×10~(-4)ppm。根据原子捕集和释放机理,本文改进了实验装置和方法,即采用贫焰捕集,脉冲富焰释放的方法,在石英捕集管上捕集0.001ppm银溶液8分钟,测得银的特征浓度为5.5×10~(-5)ppm,比常规方法的灵敏度提高1090倍。初步测定了电镀液中银含量。     

SUBSTITUENT CHEMICAL SHIFT (SCS) AND THE SEQUENCE STRUCTURE OF ETHYLENE-VINYL ALCOHOL COPOLYMERS

Three ethylene-vinyl alcohol copolymers were studied by means of the substituent chemical shift (SCS) method. The SCS parameters of hydroxy (-OH) in two different solvents were obtained: in deuterium oxide/phenol (20/80 W/W ) the parameters are S_1 = 42.77±0.08ppm, S_2 = 7.15±0.06 ppm, S_3 (s)= -4.08±0.02ppm, S_3 (t) =-3.09±0.20ppm,S_4 = 0.48±0.03ppm, S_5 = 0.26±0.05ppm. In o-dichloro-benzen-d_4 S_1(s)=44.79±0.61ppm, S_2=7.40±0.00ppm, S_3(s)=-4.51±0.17ppm, S_3(t)=-3.13 ±0.00 ppm, S_4 =0.63±0.04ppm, S_5=0.36±0.00ppm.Simultaneously the ~(13)CNMR spectra of EVA copolymers were assigned by using the SCS parameters obtained.     

离子色谱法在中药化学成分分析中的应用进展

离子色谱作为一种新型高效液相色谱技术,最初主要应用于测定样品中的阴阳离子含量,如今发展为应用于有机酸、生物胺、糖类等化合物的组成及含量测定.离子色谱法具有操作简便、灵敏度高以及选择性好等优点,因此,目前离子色谱法已在能源、环境、地质、食品、药物等领域得到了广泛应用.总结了近年来离子色谱在中药金属离子、无机阴离子、有机酸、糖类成分的研究进展,为离子色谱法分析中药化学成分提供了参考.     

Thermal behaviour of solid complexes of phenoxyalkanoic acids and divalent metals

Two solid copper(II) phenoxyacetates (anhydrous and dihydrate) were prepared and investigated by DSC and TG techniques. The results obtained indicated that the water molecules of the dihydrate compounds were weakly and differently bonded; also, both anhydrous and dihydrate compound decomposed with formation of CuO as final product, but by different steps. Some thermodynamic parameters associated with the observed thermal processes were evaluated and the results obtained were discussed and interpreted.     

Recovery of lanthanides from extraction phosphoric acid produced by the dihydrate process

Variant of precipitation of a concentrate of lanthanides from the extraction phosphoric acid formed in the dihydrate processing of the Khibiny apatite concentrate by introduction of sulfuric acid and sodium compounds into the acid is suggested. The main components of the concentrate are double sulfides of lanthanides with sodium, calcium sulfate dihydrate, and sodium hexafluorosilicate. The efficiency of recovery of lanthanides into the concentrate was studied in relation to a sodium compound used.     

任意多阶程序升温优化程序用于氨基酸对映体的分离

用氨基酸对映体在手性毛细管柱上扮离作实例, 研究了任意多阶程升优化程序的普遍适用性. 按计算结果进行实验所得的实际色谱图证明, 优化程序的应用将有助于在保证分离度的前提下, 大大缩短分析时间.提出了一种可以大体反映程序升温下复杂样品各组分在柱内运动过程的轨迹图(x-t图).轨迹图上所显示的每一组分在到达行程终点的时间的准确性得到了色谱实验的验证, 从而为探讨物质在各种条件下的柱内运动状,况特别是为多维色谱的深入研究提供了可能性.     

Thermal analysis of cis- and trans-potassium bis-malonate and bis-monomethylmalonate chromate(III) complexes

The cis- and trans-potassium bis-malonate chromate(III) dihydrate and cis- and trans-potassium bis-monomethilmalonate chromate(III) dihydrate were prepared and analyzed by TG, DTG and DSC. Detailed results are reported and the thermal stability order is discussed in terms of steric hindrance in the two configurations. Data for the corresponding tris compounds are also reported as reference.     

Theoretical and experimental comparative studies of nonlinear optical properties for selected melaminium compounds

The bis(melaminium) sulphate dihydrate, 2,4,6-triamine-1,3,5-triazin-1,3-ium tartrate monohydrate, 2,4,6-triamine-1,3,5-triazin-1-ium hydrogenphthalate, 2,4,6-triamine-1,3,5-triazin-1-ium acetate acetic acid solvate monohydrate, 2,4,6-triamine-1,3,5-triazin-1-ium bis(selenate) trihydrate, melaminium diperchlorate hydrate, melaminium bis(trichloroacetate) monohydrate and melaminium bis(4-hydroxybenzenesulphonate) dihydrate were discovered recently as perspective materials for nonlinear optical applications. On the basis of X-ray structures for eight melaminium compounds the time dependent Hartree Fock (TDHF) method was used for calculation of the polarizability, and first and second hyperpolarizability. Detailed directional studies of calculated hyperpolarizability for all investigated melaminium compounds are shown. The theoretical results are compared with experimental values of β.     

Thermodynamic evaluation of the intermolecular interactions of potassium fluoride crystal dihydrate in gas chromatography

Summary Potassium fluoride crystal dihydrate is used as the stationary phase for the rapid analysis of polar compounds in aqueous solutions. KF·2H₂O is compared with some conventional stationary phases, organic salts and molten crystal hydrates of inorganic salts.     

α-干扰素的液相色谱/毛细管电泳两维分离分析

用亲和色谱/反相色谱、亲和色谱/毛细管电泳和凝胶色谱/毛细管电泳等两维系统, 对白细胞提取液中的α-干扰素进行分离分析, 并对结果进行比较,充分肯定了亲和色谱/毛细管电泳联用在蛋白质类药物制备纯化中的显著作用,以及毛细管电泳作为此类药物分析工具的可能性。     

气相色谱柱温的智能最佳化II. 程序设计原理及其应用

本文给出了气相色谱柱温智能最佳化的程序设计原理及其应用实例, 用烃/卤代烃混合样作为实际样品进行验证, 预测值与实验值能很好吻合。     

3,3′-bi(6,8-dialkyl-2,4-dioxa-7-thia-6,8-diazabicyclo[3.3.0]-octane-7,7-dioxides): Structure and synthesis

Derivatives of a new heterocyclic system, 3,3′-bi(6,8-dialkyl-2,4-dioxa-7-thia-6,8-diazabicyclo[3.3.0]-octane-7,7-dioxides), were synthesized by condensation of 1,3-dialkylsulfamides with glyoxal (as a dihydrate trimer). Their structure was investigated by spectral methods, XRD, and X-ray phase analysis of one among these compounds.     

Thermal behaviour of solid complexes of phenoxyalkanoic acids and divalent metals

Solid Co(II) and Ni(II) phenoxyacetates were studied by DSC and TG techniques. The results showed that they were dihydrate and tetrahydrate respectively in the solid state. No evidence of the location of water molecules in different coordination shells was obtained. Both compounds decomposed with the formation of oxide as final product; the corresponding activation energies suggested a stronger metal-carboxylate bond in the nickel salt.