分子印迹技术手性分离氨基酸衍生物(Ⅱ)—流动相对分子印迹聚合物手性拆分效果的影响

系统研究了乙腈流动相中甲醇、乙酸和水的体积分数变化对分子印迹聚合物手性拆分效果的影响。在流动相乙腈中添加较少量的甲醇或乙酸时〔φ(甲醇)≤8%,φ(乙酸)≤2%〕,随其体积分数的增加,手性分离效果提高;但当其体积分数继续增加,分离效果变差。以水作为添加物质时,当体积分数相对较少〔φ(H2O)≤30%〕,随其体积分数增加,手性分离效果变差;当水体积分数继续增加,拆分效果有所提高,在φ(H2O)=70%时,选择性因子达到1 52。降低流动相的pH值有利于手性拆分。利用梯度洗脱技术可以改善色谱分离中印迹分子洗脱峰的拖尾。     

水蛭乙醇提取工艺的研究

以乙醇浸膏得率和浸膏中氮质量分数为评价指标,选择乙醇体积分数、乙醇与水蛭质量比、提取时间为考察因素,利用正交实验L9(34)确定乙醇提取水蛭最佳工艺条件为:φ(乙醇)=50%,m〔φ(乙醇)=50%〕∶m(水蛭)=6∶1,提取时间1 5h,共提取2次。平均乙醇浸膏得率13 24%,浸膏中平均氮质量分数w(N)=11 05%。     

白玉兰精油的化学成分

利用同时蒸馏萃取法提取白玉兰精油中的挥发性成分,用气相色谱/质谱法鉴定出55种化学成分,占峰面积的97.73%,挥发油得率为3.81%。主要的化合物类别有烯类,烷类,醇类,醛类等。用面积归一化法测定了各种成分的相对质量分数,其中含量较高的组分有:w(桉叶油素)=16.52%,w〔4-甲基-1-异丙基-二环[3.1.0]己-2-烯〕=13.67%,w〔6,6-二甲基-2-亚甲基-二环[3.1.1]庚烷〕=12.78%,w(十五烷)=10.42%,w(β-月桂烯)=8.49%,w(D-柠檬烯)=4.42%,w(十氢-α,,α4 a-三甲基-8-亚甲基-2-萘甲醇)=4.08%,w〔(+)-α-松油醇〕=3.13%,w(大根香叶烯)=3.03%。     

茶用香花珠兰的香气成分分析

用水蒸气蒸馏法提取珠兰挥发油,并用气相色谱-质谱联用仪对珠兰挥发油的化学成分进行了分离和鉴定,分离并鉴定出27个组分,占峰面积的85.89%,并用峰面积归一化法测定了各成分的质量分数。其主要挥发性成分为:w(反-罗勒烯)=5.71%、w(3,6二-甲基-4,5二-乙基-3,5-辛二烯)=4.61%,w〔1-(1,4二-甲基-3环-己烯基)乙酮〕=3.53%、w(2,6二-甲基-2,4,6辛-三烯)=1.45%、w(大根香叶烯B)=1.44%、w(顺-罗勒烯)=1.43%、w(大根香叶烯D)=1.40%、w(3蒈-烯)=1.25%、w(杜松醇)=1.02%。     

CAM毛细管柱测定水中甲醇方法的研究

采用气相色谱Agilent CAM毛细管柱色谱法测定水中甲醇含量。该色谱柱分离甲醇及干扰物乙醇会产生峰的展宽,因此对载气流量、柱箱温度、分流比等参数进行对比实验,建立最佳操作条件来分离甲醇、乙醇峰及优化谱图峰形。建立高含量(分流比20∶1)和低含量(分流比5∶1)两条工作曲线,都具有良好的线性关系。检测方法按2倍性噪比计算,最小检出限0.03ng。测得甲醇的相对标准偏差≤5%,平均值与标准值之间的相对误差≤±10%,加标回收率在95%～105%,在日常的监测任务中有很好的适用性。     

乳状液膜法分离富集废旧镍镉电池中的镉

该文介绍了乳状液膜法分离富集废旧镍镉电池中的镉离子。乳状液膜主要由溶剂(煤油)、表面活性剂(Span80)、载体〔二(2-乙基己基)膦酸,P204〕和内水相氨水组成。对影响镉离子渗透和分离过程的重要变量进行了考察,分析了乳状液膜的载体体积分数、外水相pH、搅拌时间、乳水比(乳液与外水相体积比)及Span80体积分数对镍镉分离效果的影响,从而选择出最佳的分离条件为:φ(P204)=4.4%,φ(Span80)=8.8%,pH=5.5,乳水比0.5,搅拌时间10min。用此乳状液膜进行100L反应釜的工业放大实验,镉的迁移率可达93.3%,而镍的迁移率仅为14.6%。     

烃重组汽油与催化重整汽油的PONA分析及其组成对比

烃重组技术和催化重整技术都可以生产高辛烷值汽油调和组分,采用气相色谱PONA分析法对烃重组汽油和催化重整汽油分别进行组成分析,并对数据结果进行对比讨论;PONA分析显示,虽然二者都是芳烃质量分数大于70%的高芳烃含量汽油,但在组成分布上存在明显不同;通过结果判断,烃重组汽油的芳烃集中在C_(8)~C_(10)范围,重整汽油中的芳烃组分宽泛存在于C_(6)~C_(11)范围;PONA谱图表明,在保留时间(60~100)min,重整汽油各组分峰几乎全部为尖锐且分离清晰的芳烃峰,而烃重组汽油谱图类似精制石脑油与重整汽油的峰形叠加,不仅包含重整汽油尖锐峰形的芳烃组分,也包含精制石脑油低矮杂多峰形的非芳烃组分。     

孤东原油组分的界面张力测定

按常规四组分分离法将孤东1#原油分离为饱和分、芳香分、胶质、沥青质,它们在原油中的质量分数分别为:45 88%,22 45%,14 73%,14 43%。将各组分在原油中所占的质量分数的十分之一和煤油配制成模拟油,模拟油与蒸馏水、碱水〔w(Na2CO3)=1 2%)〕体系的界面张力分别为:35 700,13 360;24 520,4 630;22 760,5 610;19 380,0 056mN/m。并对各分离组分进行了红外光谱、元素组成、相对分子质量测定。结果表明:界面张力的大小与各组分中的含氧量有关,含氧量越高,界面张力越低。沥青质是孤东1#原油的主要活性物质;w(沥青质)=3%时,模拟油与碱水〔w(Na2CO3)=1 2%〕体系的界面张力为0 0053mN/m。     

PVA/ P（AA-Co-AN）/ PVA渗透汽化膜的研究

制备一种PVA/P(AA-Co-AN)/PVA复合膜用于甲醇水溶液的分离,膜的主体部分P(AA-Co-AN)由添加纳米S iO2粉末的丙烯酸(AA)和丙烯腈(AN)通过溶液共聚制得,两侧为交联聚乙烯醇(PVA)。考察了复合膜在高质量分数甲醇水溶液中的溶胀性能,探讨了浸泡液温度及浸泡液质量分数对溶胀度的影响,测试了复合膜的力学性能。考察了不同单体配比〔n(AA)∶n(AN)〕所制备的复合膜在不同质量分数甲醇水溶液,不同温度下的渗透汽化性能。结果显示,复合膜在高质量分数甲醇水溶液中具有良好的溶胀性能及渗透汽化性能;在n(AA)∶n(AN)=1∶1下所制备的复合膜,对高质量分数甲醇水溶液分离效果最佳,60℃时分离w(甲醇)=98%的水溶液,分离因子可达1 534,通量为583 g/(m2.h)。     

反相高效液相色谱法同时测定喜树果中的喜树碱、金丝桃苷含量

建立了采用Zorbax C18柱,流动相为V(甲醇)∶V(0.025 mol/L磷酸)=66∶45(混合后用三乙胺调至pH 3.0~3.2),检测波长360 nm,流速0.8 mL/min,柱温25℃的同时测定喜树果(Camptotheca acurnirraca Decca)中喜树碱、金丝桃苷(Hyperin)的高效液相色谱方法。喜树碱、金丝桃苷峰形良好,与其他组分的色谱达到基线分离。金丝桃苷的线性范围是0.23~65μg/mL,回归方程:y=40.929x 100.93,r=0.9988,平均回收率为102.4%,RSD为0.76%。测定喜树碱的回归方程:y=-9.27325 33.57338x,r=1.0001,线性范围是0.10~60.0μg/mL,平均回收率为98.3%,RSD为0.90%。     

乙醇提取虎杖中的白藜芦醇

以虎杖中白藜芦醇的提取率为评价指标,研究提取剂浓度、提取温度、提取时间、料液比等因素对白藜芦醇提取效果的影响。采用正交实验法,通过紫外分光光度计测定提取液中白藜芦醇的吸光值以计算其提取率,研究虎杖白藜芦醇的最佳提取分离工艺。研究结果表明：乙醇为提取剂的最佳提取工艺是固液料比1∶15、用80%乙醇浓度作为提取剂、提取温度...     

虎杖根提取物及分离组分对黄瓜白粉病的作用效果

在实验室内进行了虎杖（Polygonum cuspidatum Sieb.etZucc.）根提取物及其活性组分分离研究,并且对黄瓜白粉病进行了活性测定及温室小区试验。结果表明,无论提取率还是作用效果,乙醇较适合于做为虎杖根提取物的提取溶剂。虎杖根乙醇提取物和乙醚提取物对黄瓜白粉病的EC90值分别为537.85、35.38mg/L,而乙醚提取后残留物的活性很弱,说明乙醇提取物中具有杀菌作用的成分主要存在于乙醚提取物中。用pH梯度分离法对乙醚提取物进行分离,得到3个不同组分,其中以氢氧化钠分离得到的组分对黄瓜白粉病显示了极高的杀菌活性。在温室条件下虎杖乙醇提取物在800～1600mg/L下对黄瓜白粉病的防效相当或优于对照药剂三唑酮。     

藻类水热液化产物生物油分离纯化及组分分析

杜氏盐藻通过水热液化制备得到的生物油,先采用溶剂分割分别得到正己烷相、二氯甲烷相和乙醚相,再对二氯甲烷相进行柱层析分离纯化。正己烷相和乙醚相直接通过GC-MS和FT-IR进行分析,二氯甲烷相先经柱层析分离后结合GC-MS、二次质谱和FT-IR等确认不同馏分的产物组成。研究结果表明:二氯甲烷相经柱层析分离可得到16个馏分,分别是石油醚馏分(A₁),主要是烯烃类;石油醚:乙酸乙酯馏分(A₂),主要是酸类化合物;石油醚:丙酮馏分(A₃),主要是酰胺类;石油醚:甲醇馏分(A₄),主要是烷烃类;甲醇馏分(A₅),主要是十八碳烯酰胺。经柱层析分离纯化后,生物油的回收率高达91.38%;获取较全的生物油组分信息,为藻类液化机理的分析和生物油的改质提供了依据。     

徐州镜煤分级分次萃取物的FTIR分析

为了研究煤中可溶有机质的存在方式与溶出行为，采用石油醚和CS2两种溶剂对徐州镜煤进行分级分次萃取，并以FTIR对各次萃取物进行了分析．结果表明：两种溶剂萃取物重要基团FTIR吸收峰随时间的变化关系均呈波形曲线变化规律；石油醚萃取时溶出的主要是煤中以游离态存在的可溶分子，脂肪族成分和含OH（-NH）的成分是其主要产物，且均以中、长链的成分为主；而CS2萃取除溶出游离态的可溶分子外，还可以渗入煤孔隙中溶出孔隙内的可溶分子，且可溶物中有大量的某种特定链长的脂肪族成分存在，而含OH（-NH）的成分则以短链的为主．     

合成气一步法制备二甲醚的工艺流程模拟与优化

二甲醚作为燃料的替代品,其生产开发在化学工程领域受到了广泛关注。本文对合成气一步法制备二甲醚过程进行了模拟分析,提出了用水作为吸收剂并采用多效精馏的二甲醚生产新工艺。利用Aspen Plus化工模拟软件对吸收塔进行模拟比较了甲醇和水作为吸收剂的能耗,模拟结果表明,用水吸收较甲醇吸收总热负荷降低23.54％,总冷负荷降低35.97％,更为节能。从节能降耗角度出发,根据不同的分离任务,提出了采用两塔分离甲醇-水及三塔分离甲醇-水的两项工艺改进措施。结果表明,采用两塔分离甲醇-水工艺比原工艺二甲醚产量增加了11.50%,能量消耗无明显变化。进一步采用三塔精馏工艺总冷负荷比原工艺减少45.07％,总热负荷减少19.27%,且二甲醚产量增加11.15％,节能效果显著。     

气相色谱法测定仲丁基溴含量内标物的确定

采用气相色谱内标法,利用9800TFP型气相色谱仪在柱箱温度:90℃,汽化温度:260℃,检测温度:260℃,柱前压:0.05MPa,采用二阶程序升温分析,结果表明乙二醇二乙醚在保留时间、峰形状都较好,可作为分析定量分析仲丁基溴的内标物,其线性回归方程为y=-0.02936+1.11691x,相关系数为0.9995,质...     

超临界流体色谱手性分离布洛芬

The separation method using chiral stationary phase （CSP） for the preparation of enantioselective compound was widely used. In this work, supercritical fluid chromatography（SFC） was proposed to resolve the chiral mixtures. To determine the optimum operating conditions for the chiral separation of the racemic ibuprofen, the retention factors and resolutions with the change in pressure, temperature and the content of IPA （%, by volume） in supercritical CO2 were investigated. Experiments showed that the retention factor decreased with the increase of pressure and decrease in temperature. The retention factor was also influenced by the content of IPA in mobile phase, as the content of IPA in the supercritical fluid increased, the retention factor decreased. The resolution of the enantiomers became worse with the increase of IPA in the supercritical fluid. Through optimizing the experimental conditions, a SFC procedure with 13MPa, 311.15K and 4% IPA in CO2 was obtained. The peak shape of the enantiomers was symmetric with supercritical fluid chromatography when compared to the asymmetric peak shape obtained by the conventional liquid chromatography. This work demonstrated that the developed supercritical fluid chromatography procedure was suitable for the chiral separation of ibuprofen enantiomers.     

Holographic polymer dispersed liquid crystals (HPDLCs) containing triallyl isocyanurate monomer

The morphology and corresponding performance of holographic polymer dispersed liquid crystals (HPDLCs) based on thiol-ene polymer are dependent on a number of factors including the gel point conversion of the polymer, polymerization kinetics, and extent of liquid crystal (LC) phase separation. Previous research of HPDLC reflection gratings made from thiol-allyl ether polymer indicates that increasing polymerization rate in systems with moderate gel point conversion can improve diffraction efficiency (DE). This work examines HPDLC reflection gratings that contain the ene monomer triallyl isocyanurate (TATATO). In HPDLCs, thiol-TATATO polymerization is two times faster than the thiol-ene polymerization of triallyl ether. By substituting TATATO for triallyl ether, the LC droplet size within HPDLC reflection gratings decreases from 100 nm to 25 nm. The dramatic reduction in LC droplet size for thiol-TATATO HPDLCs increases baseline transmission from 55% in thiol-triallyl ether HPDLCs to 90% at 450 nm. Unfortunately, the DE of thiol-TATATO HPDLCs is only approximately 10% due to poorly defined lamellae in the grating morphology. As determined with real-time IR (RTIR) spectroscopy, thiol-TATATO HPDLCs have significantly faster LC demixing kinetics in comparison to thiol-allyl ether HPDLCs. During holographic photopolymerization, the increased rate of LC demixing causes formation of LC droplets throughout the grating. The low DE of thiol-TATATO HPDLCs can be improved by mixing TATATO and allyl ether monomer. The morphology of ternary thiol-ene HPDLC formulations containing TATATO and allyl ether has a well-defined grating structure due to increased LC solubility in the system, an average LC droplet size of 50 nm, and baseline transmission of nearly 85% at 450 nm.     

不同溶剂的索式法提取酸浆果籽中油脂及成分分析

分别以乙醚、乙酸乙酯、正己烷为萃取溶剂,采用索氏萃取法提取黑龙江省产酸浆果籽获得了油脂,得油率分别为乙醚19.70%(质量分数,以下同)、乙酸乙酯19.53%、正己烷18.83%.用气质联机(GC/MS)对籽油成分进行分析的结果显示,酸浆籽油脂成分主要由亚油酸,油酸,十六烷酸和十八烷酸构成.     

Quality assessment of used frying fats: A comparison of four methods

The level of petroleum ether insoluble oxidized fatty acids in used frying fats is one of the recommended criteria for assessing their quality in Germany; however, the method of determination is time consuming and inaccurate. Gel permeation chromatography (GPC) allows the determination of dimeric and oligomeric triglycerides in a heated fat irrespective of the presence of oxidized material. An indication of the total amount of polar and oxidized compounds can be obtained by liquid chromatography (LC) on a silica gel column in connection with a moving-wire detector. A comparatively simple and quick method is the separation of polar and unpolar components in a used frying fat by means of column chromatography (CC) on silica gel. Over a large number of investigations, a good correlation was seen between the results obtained with GPC, LC, and CC and the amount of petroleum ether insoluble oxidized fatty acids isolated from used frying fats. Limits of the analytical data obtained by the new methods are proposed which indicate deterioration of used frying fats.