高效液相色谱对二苯甲烷4,4'-二异氰酸酯(MDI)及中间产物的快速测定

本文利用高效液相色谱法对二苯甲烷4,4'-二异氰酸酯(MDI)及中间产物的乙醇衍生物进行分析,实现了MDI及中间产物的测定。色谱条件:采用Agilent Eclipse XDB-C18色谱柱分离,以水-甲醇(体积比40∶60)溶液为流动相,流速1.2mL·min-1,检测波长:245nm,柱温30℃,中间产物和MDI衍生物的线性较好(r均在0.999以上)。该方法重复性好,灵敏度高,简便且快速。     

苯黄隆高效液相色谱分析

本文报道用正相高效液相色谱法，以乙腈、石油醚、氯仿、异丙醇、甲醇等混合溶剂为流动相，以邻苯二甲酸二异辛酯为内标物，对苯黄隆可湿性粉剂进行了定量分析。本方法的变异系数为０．４５％，回收率为９９．３０￣１００．１３％，线性相关系数为０．９９９９。     

二硫氰基甲烷的高效液相色谱分析方法

文章建立了一种利用反相高效液相色谱测定二硫氰基甲烷含量的方法。色谱柱为C18反相柱,流动相为60/40(体积比)的乙腈/水,柱温为室温,流速为0.9 mL/min。采用外标法定量。实验结果表明,该方法的标准偏差为0.27%,变异系数为0.28%,平均回收率为99.6%,线性相关系数为0.9999,呈良好的线性关系,该方法操作简单、快速、准确,是用于生产控制的较理想的测定方法。     

苯氧威的高效液相色谱分析

采用高效液相色谱法分析苯氧威,使用反相柱和可变波长紫外检测器,以甲醇 水 冰醋酸为流动相,外标法对苯氧威有效成分进行定量分析.其标准偏差为0.33%,变异系数为0.34%,平均回收率为100.60%.     

苯黄隆反相高效液相色谱分析

本文报道用高效液相色谱法在Ｃ１８反相柱上，以甲醇和水为流动相，以β－萘酚为内标物，对苯黄隆进行了定量分析，九次测定结果，其平均值为９０．２８％，平均回收率为９９．１￣１０１．２％，相对偏差为０．４５％，变异系数为０．６８％。     

醚苯磺隆的反相高效液相色谱分析

本文利用反相高效液相色谱外标法测定了醚苯磺隆的含量,方法的标准偏并为０．２８２４,变异系数为０．３６６８％,回收率为１００．４％。     

毒死蜱的高效液相色谱分析

关于毒死蜱的分析方法,已报道的有高效液相色谱法、紫外分光光度法及气相色谱法。但高效液相色谱法流动相的配比比较繁杂(采用乙腈、水、乙酸三者混合配比),且内标物不易找到;紫外分光光度法适宜于测纯度较高的毒死蜱原药;气相色谱法因其柱温、汽化室温度对测量结果影响较大,故重复性较差。有鉴于此,我们对液相色谱法中的流动相、流速、检测波长进行了改进,用于毒死蜱分析的结果证明,效果较为理想,方法简便迅速。     

苯噻菌酯的高效液相色谱分析

[目的]建立苯噻菌酯的高效液相色谱分析方法。[方法]采用高效液相色谱法,使用C18反相色谱柱,以乙腈-三氟乙酸水溶液(体积比65∶35)为流动相,流速为0.8 mL/min,在UV230 nm下,对苯噻菌酯进行定量测定。[结果]在0.1~10.0 mg/L范围内,苯噻菌酯质量浓度与色谱峰面积呈良好的线性关系,相关系数为0.9999,标准偏差为0.0172,变异系数为0.332%,平均回收率为102.7%。[结论]方法具有简便、快速、精密度和准确度高、线性关系好等优点,适用于苯噻菌酯的定量分析。     

SO_3H-功能化离子液体催化4,4'-MDC合成反应

The synthesis of methylene diphenyl dimethylcarbamate (4,4′-MDC) from methyl N-phenyl carbonate (MPC) and formaldehyde (HCHO) was conducted in the presence of sulfonic acid-functionalized ionic liquids (ILs) as dual solvent-catalyst. The influences of the kind of anion in the ionic liquids, reaction conditions and the recycle of the ionic liquid on 4,4′-MDC synthesis reaction were investigated. In addition, the acid strength of ILs was determined by the Hammett method with UV-visible spectroscopy, and the acid strength-catalytic activity relationship was correlated. The activity estimation results showed that [HSO3-bmim]CF3SO3 was the optimal dual solvent-catalyst. Under the suitable reaction conditions of 70°C, 40 min, molar ratio of nMPC/nHCHO 10/1 and mass ratio of WILs/WMPC 4.5/1, the yield of 4,4′-MDC based on HCHO was 89.9 % and the selectivity of 4,4′-MDC with respect to MPC was 74.9%. Besides, [HSO3-bmim]CF3SO3 was reused four times after being purified and no significant loss in the catalytic activity was observed.     

双酚A及其衍生物的热分解动力学研究

采用热分析方法(TG,DTA)、热分解气相色谱和红外光谱等联合手段,对双酚A(2,2-双对羟基苯基丙烷)及两个二取代产物[2,2-二(4-羟基-3-硝基苯基)丙烷和2,2-二(3-氨基-4-羟基苯基)丙烷]的热稳定性和热分解反应动力学进行了研究,发现它们的稳定性和分解机理与取代基性质有关,建立了相应的动力学方程,并对其稳定性、热解机理从电荷分布出发进行了理论分析。     

Thermal decomposition of 4,4′-azobis(4-cyanopentanol)

Summary Several workers (Reed, 1971, 1972, Goldfein, 1975, Kartavykh, 1977) have employed the 4.4-azobis(4-cyanopentanol) (ACP) as the initiator for the radical polymerization of butadiene, isoprene or acrylic monomers. Nevertheless, the decomposition of (ACP) has never been studied, only the rate constant of decomposition (k_d) of (ACP) at 70 °C in acetone has been determined.The present paper reports the kinetics of the thermal decomposition of (ACP): the rate constant of decomposition (k_d) at various temperatures and the activation energy of decomposition are determined in dimethyl sulfoxide.     

Metaettringite, a decomposition product of ettringite

Dehydroxylation of ettringite in an atmosphere of constant partial water vapour pressure (30-400 Torr) and controlled temperature (55-95 °C) yields an X-ray amorphous product containing 11-13 H₂O per ettringite formula unit. The X-ray amorphous product does, however, give electron diffraction patterns similar to those of ettringite but with a considerably reduced from ∼1.123 nm (ettringite) to 0.85 nm in the partially dehydroxylated product, termed metaettringite. The structure of metaettringite is closely related to that of fleischerite, Pb₃Ge[(OH)₆](SO₄)₂·3H₂O and the isostructural despujolsite, Ca₃Mn^IV(SO₄)₂(OH)₆·3H₂O. These minerals contain columnar units. The columnar structure is like that of ettringite but with closer packing of columns in the a direction, resembling metaettringite.The mechanism of collapse of ettringite to metaettringite, involving loss of water and motion of columns, cannot be achieved without scissoring and possibly rotation of individual columns; this and other defect-producing mechanisms result in loss of crystallinity of the metaettringite product.     

医疗固体废弃物热解及其产物特性分析

目前关于医疗固体废弃物热解的研究主要集中在热解条件对产物分布的影响,在产物成分及应用方向少有报道。本试验将预处理后的医疗固体废弃物在450～550℃下进行热解处理,对热解后产生的气体、液体、固体三相产物,系统地分析了其成分及产物特性,并提出其进一步资源化利用方向。结果表明,所得气体产物中可燃组分占83.17%,热值为10995kcal/m³（1kcal=4.18kJ）;液体产物热值为8973kcal/kg,进一步分离提纯后所得产物中烃类组分占67.81%,热值可达10214kcal/kg;固体产物经过改质后,碳含量高达63.13%,热值为5455kcal/kg。研究表明,医疗固体废弃物热解得到的气、液、固三相产物在资源化利用方面都具有一定的价值,除了可以直接用作替代燃料外,三相产物中均含有多种应用广泛的化工原料。     

Modelling of organic liquid-phase decomposition reactions through gas-phase product analysis: Model systems and peracetic acid

A new method for modelling of liquid-phase decomposition reactions was developed. The method is based on rapid on-line mass spectrometric analysis of liberated products in gas phase. The experimental set-up and the generalized modelling principles were introduced. The approach was demonstrated with first and zero order as well as for complex decomposition kinetics (decomposition of peracetic acid). The interaction of decomposition kinetics and mass-transfer effects was illustrated with theoretical and real reaction conditions. The approach is generally applicable to any liquid-phase decomposition, provided that gaseous products can be quantitatively analyzed.     

Epoxy resins based on aromatic glycidylamines. IV. Preparation of N,N,N′,N′-tetraglycidyl-4,4′-diaminodiphenylmethane from aniline and analysis of the product by GPC and HPLC

Epoxy resins containing N,N,N′,N′-tetraglycidyl-4,4′-diaminodiphenylmethane (TGDDM) were prepared from aniline and epichlorohydrin and analyzed by GPC and HPLC. The product composition was compared with that of resins prepared from 4,4′-diaminodiphenylmethane (DDM) and epichlorohydrin, which had been analyzed in our previous work. A new byproduct designated Y4 was isolated by semipreparative HPLC and identified by NMR and mass spectroscopy. The course of formaldehyde condensation with N,N-dichlorohydrin of aniline (DCHA) was followed by GPC and HPLC and the mechanism of formation of Y4 was proposed on the basis of obtained results. Attention was also paid to the differences in reactivity of DCHA diastereoisomers.     

PTT纤维及其产品开发

介绍了PTT纤维的发展史、优越性能如良好的拉伸回弹性,柔软性,垂坠性,低温染色性,抗污性。概述了其在服用、产业用、装饰用三大纺织领域的应用以及PTT纤维在国内外的发展。     

碳酸氢钠湿分解技术及其应用

回顾了我院重碱湿分解技术开发的过程,介绍了目前湿分解技术在工业中的应用情况.     

辛酸TSEPIP荧光衍生物制备及荧光光谱研究与分析应用

合成了荧光衍生试剂1-[2-(对甲苯磺酸酯)乙基]-2-苯基咪唑[4,5-f]9,10-菲(TSEPIP),经衍生化和固相萃取制得了TSEPIP的辛酸衍生物(TSEPIP-C8)。研究了TSEPIP-C8在包括溶剂极性、温度、卤素离子、重金属离子等不同的溶液环境因素影响下的荧光光谱性质,为高效液相色谱荧光分析检测提供了依据。在EclipseXDB-C8反相色谱柱上,在380nm检测波长下采用梯度洗脱,实现了26种脂肪酸(FFA)TSEPIP衍生物的基线分离,应用该法完成了丹参中脂肪酸的含量分析。借助柱后串联质谱APCI大气压化学电离源正离子模式,能够实现各组分的快速定性。26种脂肪酸的线性回归系数均>0.9996,检出限为3.824～47.13fmol(进样量10μL,信噪比为3:1)。