双波长分光光度法同时测定日落黄与柠檬黄

采用双波长分光光度法同时测定食品中日落黄与柠檬黄,其标准曲线的相关系数为r柠＝0．9999,r日＝0．9998,平均回收率也符合要求,该方法简便,所使用仪器普遍。     

柠檬黄的吸附伏安法测定

<正> 柠檬黄,其结构式为■是我国规定使用的人工合成食用色素之一。它是由煤焦油产物苯胺合成的,具有一定的毒性,用量大时对人身健康不利。我国卫生部规定人工合成色素的最大允许量为万分之一,因此对食品中色素含量的分析,对保障人民身体健康至关重要。     

高纯度单月桂酸甘油酯的酶催化合成

采用脂肪酶Novozyme 435催化月桂酸甲酯与甘油进行酯交换反应制备单月桂酸甘油酯。以反应体系中单月桂酸甘油酯的质量分数为考察指标,通过单因素实验和正交实验对酶催化合成工艺进行优化,得到最佳的工艺条件为:底物摩尔比n(月桂酸甲酯)∶n(甘油)=1∶5,底物质量分数为20%(即月桂酸甲酯与叔丁醇的质量百分数,下同),反应温度为55℃,酶添加量为7%(即酶与月桂酸甲酯的质量百分数,下同),初始含水量为20%(以月桂酸甲酯质量计,下同),转速为100 r/min,反应时间为1 h,在该条件下,体系中单月桂酸甘油酯的质量分数为71.86%。经提纯后终产物中单月桂酸甘油酯的质量分数高于95%,最高可达98.76%,而双月桂酸甘油酯的质量分数低于5%。酶重复使用6次,单月桂酸甘油酯的质量分数从71.75%降至68.36%,其催化性能无显著降低。     

双波长K系数分光光度法同时测定日落黄与柠檬黄

采用双波长K系数分光光度法同时测定饮料中的日落黄和柠檬黄,其中日落黄的回归方程为A1/A2=0.9083+2·604×10~(-2)c/A2,r_日=0.9998,线性范围为5～60μg/mL,柠檬黄的回归方程为A1/A2=0.9105+3.204×10~(-2)c/A2,r_柠=0.9999,线性范围为10～55μg/mL。对实际样品的测定表明,日落黄的加标回收率为99.72％,柠檬黄的加标回收率为94.76％,比双波长法更符合要求。     

高纯度苯乙腈制备工艺研究

采用ＧＣ－ＭＳ方法分析苯乙腈制备过程中的副产物,进而推测出发生的副反应。选择了合适的催化剂,ｐＨ和温度等工艺条件来抑制副反应的发生,获得高收率和高纯度苯乙腈。在复合相转移催化剂的存在下,过量２％－５％的氯化苄在７０℃－８０℃时滴加到３０％氰化钠中反应,ｐＨ维持在９－１０,然后减压蒸馏粗品可得到含量为９９％的苯乙腈,收率〉９９％。     

示差脉冲极谱法测定柠檬黄

建立了示差脉冲极谱法测定饮料中的合成色素柠檬黄的新方法。在pH 6.00的磷酸盐缓冲溶液中,柠檬黄在-0.59 V处产生一灵敏的还原峰,在1.25×10-6～4.37×10-5 mol/L浓度范围内,其峰电流与浓度呈线性关系,线性回归方程为ip（μA）=2.46×106 c（mol/L）＋11.4（相关系数r=0.970）,实验检出限为0.27μg/mL。利用该方法测定了两种市售饮料中柠檬黄,加标回收率在87.5%～109.6%之间。     

聚合物支载相转移催化剂的制备及应用

综述了以交联聚苯乙烯为支载体 ,各种冠醚、盐等为相转移催化功能团的P -PTC和其它非聚苯乙烯为支载体的P -PTC的制备及它们在各类相转移催化反应中的应用。     

相转移催化合成丁酸苄酯的研究

丁酸和氯化苄为原料,以新洁而灭为相转移催化剂合成了丁酸苄酯。通过实验,考查了催化剂用量、反应时间、反应温度及物料配比对反应的影响。结果表明,最佳的反应条件是:反应温度为135℃,催化剂用量为0.75mL,反应时间为2.0h,氯化苄与丁酸钠物质的量的比为1.3∶1。在此条件下,收率在93.5%以上,通过折光率、元素分析、红外光谱分析、色-质分析对产品进行了表征。     

相转移催化法合成对甲氧基苯乙醇酸的研究

以对甲氧基苯甲醛、三氯甲烷为原料,相转移催化羰基加成法合成了对甲氧基苯乙醇酸。分析探讨了其相转移催化机理及合成工艺参数。     

相转移催化技术在无机化工中的拓展

相转移催化理论一直应用于有机物的合成领域。相转移催化技术也可用于无机盐水溶液或固态盐类与有机物之间的液—液和固—液多相反应。将相转移催化技术理论首次拓展到无机难溶盐之间的固—固类型转化反应中 ,利用此技术 ,可从生产硼砂的废渣硼泥中提取出轻质碳酸镁 ,为硼泥的综合利用提供了一条经济、切实可行的途径     

Removal of Tartrazine From Water by Adsorption with Electrochemical Regeneration

An innovative process has been developed at University of the Manchester in order to remove organic contaminants from wastewater using graphite intercalation compounds (GICs) as adsorbents with electrochemical regeneration. The present study has demonstrated the removal of tartrazine, from water by adsorption and electrochemical regeneration. The adsorption of tartrazine onto GIC adsorbent was shown to be a quick process, however, with extremely low adsorption capacity compared to porous adsorbents. Low adsorption capacity of the adsorbent is being compensated by rapid electrochemical regeneration associated with low energy consumption that makes the process cost-effective. Regeneration efficiency of around 100% could be obtained in an electrochemical cell by passing a charge of 18 C g^?1 for 18 min through a 10-mm thick adsorbent bed. A series of adsorption and regeneration cycles showed that there was little loss in adsorbent capacity, demonstrating that tartrazine loaded GIC adsorbent could be effectively regenerated electrochemically.     

2,5-二丁氧基一4一吡啶基苯基重氮氯化锌复盐的合成

以对苯二酚为原料合成了一种新的感光试剂2,5-二丁氧基-4-吡啶基苯基重氮氯化锌复盐.采用Williamson反应合成了1,4-二丁氧基苯,考察了各种因素对产率的影响并得出最佳条件.利用元素分析、IR和1HNMR对最终产物和中间产物进行了结构表征,并对其感光性能进行了初步的研究.     

2,5-二丁氧基-4-吡啶基苯基重氮氯化锌复盐的合成

以对苯二酚为原料合成了一种新的感光试剂２,５－二丁氧基－４－吡啶基苯基重氮氯化锌复盐。采用Ｗｉｌｌｉａｍｓｏｎ反应合成了１,４－二丁氧基苯,考察了各种因素对产率的影响并得出最佳条件。利用元素分析、ＩＲ和１ＨＮＭＲ对最终产物和中间产物进行了结构表征,并对其感光性能进行了初步的研究。     

三唑磷的相转移催化合成及其稳定性

相转移催化合成三唑磷 ,收率 93% ,原药纯度 91%。产品经过 5 0℃、14天的热贮存试验 ,稳定性合格     

相转移催化剂在氰氟草酯合成中的应用

以(R)-2-(4-羟基苯氧基)丙酸与3,4-二氟苯腈为原料,通过使用相转移催化剂四丁基硫酸氢铵,以二甲基甲酰胺(DMF)为溶剂,反应温度为80℃,制得了(R)-2-[4-(4-氰基-2-氟苯氧基)苯氧基]丙酸钾,再与溴丁烷反应酯化合成氰氟草酯。反应产率达到94%,产品化学纯度为96%,光学纯度为98%。     

Structure formation and characterization of EVAL membranes with cosolvent of isopropanol and water

Microporous poly (ethylene-co-vinyl alcohol) (EVAL) membranes can be prepared by the solution casting method in combination of thermally induced phase separation (TIPS) with solvent evaporation. A cosolvent of isopropanol and water (3:2 w/w) is used to prepare the casting solution. EVAL membranes of different bulk or true densities, porosity, flexibility, crystallinity, and structure can be obtained by adjusting the casting temperature. A pseudo-binary temperature-concentration phase diagram of the EVAL-cosolvent system has been proposed, based on the information obtained from SEM, DSC, and light transmittance studies, to account for the membrane formation mechanism. The dense membranes were obtained when the casting temperature was higher than the upper critical solution temperature (UCST) of the system, but they might contain some nonSEM-observable micropores if the casting temperature was below the glass transition temperature (T_g) of EVAL. The porous and the least crystalline membranes with a honeycomb-like morphology were obtained through liquid-liquid demixing and vitrification at a casting temperature between the UCST and the dynamic crystallization temperature (T_c). Highly porous and crystalline membranes were obtained when they were prepared at temperatures near T_c. In this case, the particulate membranes were resulted from solid-liquid demixing mainly via TIPS, and membranes with leafy morphology were created through liquid-liquid demixing and then followed with immediately crystallization.     

相转移催化合成乙酸苄酯

采用氯苄和乙酸钠三水合物为原料,二甲苯为溶剂,十二烷基三甲基氯化铵为相转移催化剂,对乙酸苄酯的合成反应进行了改进。在反应温度为120~130℃,n(氯苄)∶n(乙酸钠三水合物)∶n(催化剂)=1∶1.3∶0.03的较佳工艺条件下,氯苄转化率≥99.5%,产品收率≥98.3%,产品含量≥99.8%。