DEAE-纤维素法从琼脂中分离制备琼脂糖工艺研究

采用DEAE-纤维素法静态和动态两种工艺从琼脂中分离制备琼脂糖,并考察了最佳工艺条件。静态吸附的最佳工艺条件为:在80℃下,浓度为40g/L的琼脂溶液与25g DEAE-52纤维素进行4h的离子交换,制得的琼脂糖凝胶强度为1028g/cm2,硫酸根含量为0.208%,透明度为64.0%,凝固温度为36.0℃,融化温度为90.2℃,得率为57.2%;动态吸附的最适工艺条件为:在80℃下,浓度为8g/L的琼脂溶液,以1.5m L/min的上样流速流经填充60g DEAE-52纤维素的层析柱,制得的琼脂糖凝胶强度为1040g/cm2,硫酸根含量为0.159%,透明度为65.8%,凝固温度为36.5℃,融化温度为89.8℃,得率为50.3%。DNA Marker电泳实验表明,自制琼脂糖具有优异的电泳性能,能满足生化实验要求。     

双波长补偿计算法同时测定饮料中的日落黄及胭脂红

采用双波长补偿计算法同时测定饮料中的食用合成色素日落黄与胭脂红。日落黄的线性范围为4～60μg／mL，相关系数为0．9999，回收率为97．9％，RSD为0．7164％；胭脂红的线性范围为20～60μg／mL，相关系数为0．9999，回收率为100．5％，RSD为0．7670％。该法操作简单，灵敏度高。     

甘薯中总硒含量和无机硒含量分析的响应面优化

以富硒甘薯为材料,采用单因素实验结合响应面分析法,对原子荧光光谱法测定甘薯薯块中硒含量的条件进行了优化。结果表明,薯块中硒含量的最佳测定条件为:鲜薯样品烘干温度为40℃,硝酸和高氯酸的混合酸比例为5∶1,介质盐酸浓度为20.0%,载液盐酸浓度为5.0%,硼氢化钾浓度为(30g/L),抗干扰剂铁氰化钾浓度为25μg/mL;测定无机硒含量的最适前处理条件为:提取液为乙醇(45%),水浴温度为40℃,超声提取时间为30min。方法的加标回收率为96.70%～106%,检出限为0.031 4μg/L。方法测定结果可靠,适用于甘薯中硒含量的检测。     

微波场协同提取野菊花黄色素的研究

研究了微波提取野菊花 (Chrysanthemumindicum)黄色素的新工艺并确定了最佳工艺条件 :原料为 2 0 0 0 0g野菊干花 ,提取剂为无水乙醇 ,提取剂比例为 1 /70 ,微波功率为 80 0W ,提取时间为 45 0s,提取次数为 3次 ,最佳工艺条件下色素的提取率为 91 1 % ,产率为 1 4 6% ,色价E ( 1 % ,3 2 1nm)为 42 2 ,产品pH值为 6 5。与溶剂浸提法相比 ,微波提取野菊花黄色素的每次提取时间由 1 2h减小为 45 0s,提取率从 88 6%增加到 91 1 %。     

大白菜、甘蓝和西兰花中锐劲特残留量气相色谱分析方法的研究

建立了大白菜、甘蓝和西兰花3种蔬菜中的锐劲特残留量分析方法。以乙腈为提取溶剂,使用弗罗里硅土SPE小柱净化,最后利用GC-ECD进行检测,仪器最小检测量为5×10-13g,最低检出浓度为0.0005 mg/kg。在大白菜中平均回收率为85.11%~89.81%,RSD为3.8%~6.8%;甘蓝中平均回收率为91.39%~102.92%,RSD为5.2%~8.3%;西兰花中平均回收率达到91.92%~101.64%,RSD为4.5%~6.8%。     

稀土固体超强酸SO~4^2^-/TiO~2/La^3^+催化合成水杨酸 异丁酯

研究了以稀土固体超强酸SO~4^2^-/TiO~2/La^3^+为催化剂,水杨酸和异丁醇为原料合成水杨酸异丁酯,并考察了影响反应的因素。结果表明,醇酸比为3:1,催化剂用量为1.0g(水杨酸为0.1mol的情况下),带水剂苯为15mL,反应时间为3.0h是最适宜的反应条件,酯化率达96.2%。     

多菌灵原药中2个酚嗪类杂质含量的高效液相色谱法测定

建立了高效液相色谱法测定多菌灵原药中2个酚嗪类杂质(2,3-二氨基酚嗪(DAP)和2-羟基-3-氨基酚嗪(HAP))含量的方法.采用紫外-可见光检测器,检测波长为453 nm,分析柱为Zorbax SB-C18色谱柱,以甲醇-0.05 mol·L-1乙酸铵溶液(体积比50:50,pH 3.0)为流动相,流速1.0 mL·min-1.DAP在0.136～2.18 mg·L-1质量浓度范围呈线性响应,相关系数为0.999 9,检出限为0.03 mg·L-1,相对标准偏差为1.08%,平均加标回收率为99%;HAP在0.10～1.60 mg·L-1质量浓度范围呈线性响应,相关系数为0.999 9,检出限为0.05 mg·L-1,相对标准偏差为2.71%,平均加标回收率为98%.     

新型含季铵基腈纶纤维的制备

以商品级腈纶为基体,二甲氨基丙胺(Ⅰ)为胺化剂,经胺化反应制得含叔胺基的腈纶纤维(1)。以溴辛烷(Ⅱ)为季铵化试剂对1进行季铵化改性,制得新型的含季铵基的腈纶纤维(2),其结构经IR和EDS表征。较佳的胺化反应条件为:以乙二醇为溶剂,Ⅰ的体积分数为30%,于118℃反应3 h。较佳的季铵化反应条件为:以乙醇为溶剂,Ⅱ.的体积分数为10%,于70℃反应6 h。     

成都市东郊土壤中重金属元素垂直分布研究

采用王水消解样品,利用原子吸收分光光度法,对重金属元素(Cu、Pb、Zn、Cd)在成都市东郊土壤中的垂直分布进行了研究。该法对Cu的回收率为98%~104%,精密度为2.75%;Pb的回收率为95~97%,精密度为3.11%;Zn的回收率为99%~101%,精密度为2.31%;Cd的回收率为97%~102%,精密度为3.32%,测定方法简单、准确。     

活性炭固载氯化铁催化合成柠檬酸三丁酯

研究了以活性炭固载氯化铁为催化剂 ,柠檬酸和正丁醇为原料合成柠檬酸三丁酯 ,通过正交试验和单因素检验确定了最佳合成条件 ,结果表明 :当柠檬酸用量为 0 .1mol时 ,正丁醇用量为 0 .5mol,催化剂用量为 4g ,在回流温度控制反应时间为 2h ,其酯化率可达 95 .7%     

Synthesis of Diacetals of 2,2-bis(Hydroxymethyl)-1,3-Propanediol Under Microwave Irradiation

Nine diacetals (3a-i) of 2,2-bis(hydroxymethyl)-1,3-propanediol (2) were prepared by condensation of aldehydes with 2 under microwave irradiation in the presence of TsOH without solvent.     

1,3-二噁烷环的双磺酸盐表面活性剂的微波合成

在微波辐射下, 以磷钨酸为催化剂, N,N-二甲基甲酰胺为溶剂, 将2,2-二羟甲基-1,3-丙二醇与醛缩合合成了单缩醛, 然后与氢化钠和1,3-丙磺内酯反应得到含1,3-二噁烷环的双磺酸盐表面活性剂. 产物经过元素分析、IR和¹H NMR表征.     

Trichloroisocyanuric Acid,as an Industrial Chemical,Promotes Transthioacetalization of Diacetals of 2,2-Bis (Hydroxymethyl)-1,3-propanediol and Cleavage of Thioacetals

Trichloroisocyanuric acid has been used as a mild, efficient, and new catalyst for transthioacetalization of diacetals of 2,2-bis (hydroxymethyl)-1,3-propanediol in CH 2 Cl 2 at room temperature. A clean, easy, and general method for efficient deprotection of thioacetals to their corresponding carbonyl compounds using trichloroisocyanuric acid/silica gel and water system also is described.     

二代螺环树形化合物1,2,3,4,5,6,7,8,9,10,11,12-十二氢-2,2;6,6;10,10-三[3,3-二(烷氧羰基)-1,1-环亚丁基二甲氧基]三亚苯基的合成

以1,4-环己二酮、丙二酸二乙酯及多元醇等为原料, 经过两次“一锅煮”法合成了六种二代螺环树形化合物1,2,3,4,5,6,7,8,9,10,11,12-十二氢-2,2;6,6;10,10-三[3,3-二(烷氧羰基)-1,1-环亚丁基二甲氧基]三亚苯基螺环树形化合物, 其中烷氧基为异戊氧基、三羟甲基甲氧基、2,2-二溴甲基-3-羟丙氧基、2,2-二羟甲基丙氧基、二羟甲基膦甲氧基和(N-羟甲基-N-二羟甲基氨基乙基)甲氧基. 利用IR, NMR, MS和元素分析对合成的化合物进行了结构认证, 对影响反应的因素进行了讨论.     

Lipophilic complexones,part 3. Synthesis of polyamines derived from 2-alkyl-1,3-propanediols and 2,2-bis(hydroxymethyl)alkanols

Lipophilic di-, tri-, tetra-, and hexaamines were synthesized from 2-alkyl-1,3-propanediols and 2,2-bis(hydroxymethyl)alkanols. The alcohols were converted into the sulfonate esters which were substituted with ethylenediamine or sodium azide. The azides were directly reduced to give amines. Also dioxyethylenated 2-octadecyl-1,3-propanediol yielded the corresponding amine. Some amines were converted into the salicylidene derivatives.     

New Applications of Solid Silica Chloride (SiO 2 -Cl) in Organic Synthesis. Efficient Preparation of Diacetals of 2,2-Bis(Hydroxymethyl)-1,3-propanediol from Different Substrates and Their Transthioacetalization Reactions. Efficient Regeneration of Carbonyl Compounds from Acetals and Acylals

A new application of solid silica chloride, an easily available and efficient catalyst for the preparation of diacetal of 2,2-bis-(hydroxymethyl)-1,3-propanediol from aldehydes, acetals, acylals, and oximes, is described. Transthioacetalization of diacetals of 2,2-bis-(hydroxymethyl)-1,3-propanediol into their corresponding 1,3-dithianes and 1,3-dithiolanes in the presence of silica chloride is presented. Efficient regeneration of carbonyl compounds from their corresponding acetals, ketals, diacetals, and acylals in the presence of this catalyst also is described.     

A New Perspective of Enthalpies of Proton Transfer of Aliphatic Amines, Hydroxyamines, and Aminoalkylsulfonic Acids in Methanol–Water Mixtures by Direct Calorimetry

The enthalpies of proton transfer in methanol–water mixtures (0–90 wt.% methanol) of the aliphatic amines: triethylamine (Et₃N), t-butylamine, and quinuclidine (Q); the hydroxyamines:2-amino-2-methyl-1-propanol (Amp), 2-amino-2-methyl-1,3-propanediol (Bis), tris(hydroxymethyl)-aminomethane (Tris), and 2,2-bis(hydroxymethyl)-2,2′,2′′-nitrilotriethanol (Bis-Tris); and the aminoalkylsulfonic acids: 3-(N-morpholino)-propanesulfonic acid (MOPS), N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid (Bes), and N-(2-hydroxyethyl)piperazine-N′-2-ethanesulfonic acid (HEPES), have been measured by direct calorimetry at 25°C. The results of the protonation reactions have been reported. All the salient features are now examined together with a view to assessing the success of interpretations using classical electrostatic formulation and three-dimensional structures in methanol–water mixtures. The objective is to find answers to the complex phenomena of solvation.     

Enthalpies of proton transfer of hydroxy amines and maltol in methanol-water mixtures by direct calorimetry

Enthalpies of proton transfer in methanol-water mixtures (0–90 wt. % methanol) have been measured by direct calorimetry for the bases 2-amino-2-methyl-1-propanol, 2-amino-2-methyl-1,3-propanediol and 2,2-bis(hydroxymethyl)-2,2,2-nitrilotriethanol at 25°C. Also reported are the data for 3-hydroxy-2-methyl-4-pyrone. The results are discussed in terms of an adaptation of classical electrostatic formula.     

Facile synthesis of enantiopure 1,1′-binaphthyl-2,2′-dicarboxylic acid via lipase-catalyzed kinetic resolution

Enantiopure 1,1′-binaphthyl-2,2′-dicarboxylic acids (R)-1 and (S)-1 have been synthesized through the lipase-catalyzed kinetic resolution of the racemic 2,2-bis(hydroxymethyl)-1,1′-binaphthyl (±)-2 and subsequent oxidation of the hydroxymethyl groups.     

Preparative Synthesis and Structure of 2,2-Bis(hydroxymethyl)propyl and 2,2-Bis(hydroxy-methyl)butyl Phosphites

Conditions were found for selective hydrolysis of bicyclic phosphites derived from 2,2-bis-(hydroxymethyl)-1-propanol and 2,2-bis(hydroxymethyl)-1-butanol to the corresponding dihydrogen phosphites. The latter were isolated as potassium, sodium, and ammonium salts and were characterized by the ¹H, ¹³C, and ³¹P NMR spectra. The structure of the ammonium salt was proved by X-ray analysis.