超声波辅助从浓缩磷脂中提取高纯粉状磷脂的研究

以大豆浓缩磷脂(CSP)为原料,丙酮为溶剂,提取高纯度粉状磷脂。针对传统有机溶剂法萃取制备粉状磷脂工艺过程中,物料粘度大,容易团聚成块,脱油操作极其困难,萃取效率低等问题,提出了超声波辅助均质萃取新技术。并对较佳的工艺操作条件的选择进行了研究。通过正交实验得出优化的条件为:萃取次数5次,萃取温度0℃,浓缩磷脂与丙酮之比为1/12g/mL,超声波辅助剪切转速5000r/min。产品丙酮不溶物可达98%以上。     

丙酮-乙酸异丙烯酯二元体系常压汽液平衡

用改进的埃利斯(Ellis)平衡蒸馏器测定了丙酮-乙酸异丙烯酯二元系统在常压下的汽液平衡数据,用液相活度模型Wilson、NRTL方程对测定数据进行关联,采用非线性最小二乘法回归出二元系统在常压下的Wilson、NRTL方程参数,Wilson模型与试验值符合良好.汽液相平衡数据经Herrington面积法检验满足热力学一致性.     

毛细管气相色谱法分析丙酮和丁醇发酵产物

建立了毛细管气相色谱法,测定丙酮和丁醇发酵产物中丙酮、丁醇、乙醇含量的方法。采用HP-INNO- WAX(19091N-236)毛细管柱(60m×0.251mm×0.50μm),氢火焰离子化检测器(FID),柱温程序升温,以高纯氮作为载气,流速1mL/min,分流比90:1,进样量1.0μL,以内标法定量。在确定的色谱条件下,乙醇、丙酮、丁醇线性关系良好,线性回归系数≥0.9993,平均回收率在99.2%～99.8%,相对标准偏差≤2.50%,最低检测限分别为0.10μg/mL,0.12μg/mL和0.20/μg/mL。该方法简单,灵敏度高,重复性好,结果准确,适合用于丙酮和丁醇发酵产物的检测。     

Acetone transformation into methyl isobutyl ketone over Pt/HMFI catalysts. IV. Effect of density and strength of the acidic sites

Acetone transformation into methyl isobutyl ketone (MIBK) was studied using a fixed-bed dynamic reactor at 160°C, 1 atm pressure and acetone/H₂ molar ratio=3. The reaction was carried out over Pt/HMFI bifunctional catalysts, with 0.30 wt% of platinum which was supported over three aluminosilicates (Si/Al ratio=40, 95 and 160) and a borosilicate (Si/B ratio=44) with similar dispersion. The results show that catalytic properties depend greatly on density and strength of the acidic sites of the catalysts. Moreover, the limiting step of the MIBK synthesis reaction (aldolization of two acetone molecules) is carried out over the acidic sites of the aluminosilicates, but not over those of the borosilicate, which considerably affects reaction selectivity. This revised version was published online in July 2006 with corrections to the Cover Date.     

6-APA中残留丙酮、甲基异丁基酮的测定

采用直接进样色谱法测定,并用内标法（2-戊酮作内标物）定量,确定6-APA中残留丙酮、甲基异丁基酮的检测方法。经验证此法可准确测定6-APA中丙酮、甲基异丁基酮的残余量。     

微波辅助丙酮提取大蒜油工艺的研究

为提高大蒜油的得率,增加大蒜的附加值,采用微波辅助、丙酮提取的方法进行大蒜油提取工艺.通过单因素和正交试验考察微波的功率、大蒜和丙酮的配比、微波提取的时间和丙酮的浓度对大蒜油提取得率的影响.结果表明,大蒜和丙酮的配比为大蒜油提取工艺的最显著影响因素;最佳的工艺条件是,微波功率100 W、微波提取时间75 s、液料比25∶1、丙酮体积分数为90％时,大蒜油的提取率最高,提取率为3.85％.     

Modification of Crude Canola Lecithin for Food Use

Crude canola lecithin was fractionated by removal of neutral lipids with acetone followed by ethanol extraction with or without supercritical carbon dioxide (SC-CO₂). Two extraction steus of 60 min each at 35°C with 500 mL acetone were optimum for maximum yield of acetone solubles and maximum phospholipid (PL) concentration (66.7%) in the acetone insoluble (AI) fraction. AI were separated into 26.5% ethanol soluble and 68.7% ethanol insoluble fractions. PL concentration in the extract increased with increasing amounts of ethanol used. Yields were low for SC-CO₂/ethanol extraction, of which extracts from 55.2 MPa/ 70°C contained 32% PL (83% phosphatidyl choline).     

乙醇提取-丙酮沉淀法提取分离茶皂素的工艺研究

以油茶饼粕为原料,采用乙醇提取-丙酮沉淀法对茶皂素进行提取分离。以茶皂素纯度和得率为考察指标,对乙醇体积分数、液料比、提取温度、提取时间、提取次数、提取液浓缩程度和丙酮用量等工艺参数进行了单因素优化。结果表明：体积分数95%的乙醇为提取溶剂,乙醇与预处理过的油茶饼粕液料比为9：1（mL：g）,提取温度为70℃,提取时间为4 h,提取次数为2次,提取液浓缩至刚好有固体析出,丙酮用量为4倍浓缩液体积量时提取分离效果较佳,得到的茶皂素纯度为85.17%,得率为9.82%。不同溶剂打浆对产品纯化效果的比较发现：丙酮、乙酸乙酯、无水乙醇、体积分数95%的乙醇作为打浆纯化溶剂用于提高茶皂素纯度效果均不明显。     

工业苯酚丙酮装置氧化尾气的气相色谱分析

采用质量分数2.5%的邻苯二甲酸二壬酯和质量分数2.5%的硅藻土,以chromsorb G·DMCX(150~180μm)为担体的色谱填充柱进行分离,氢火焰离子化检测器进行检测,用峰面积外标法进行定量分析,同时对工业苯酚丙酮装置氧化尾气组成进行气相色谱分析。对色谱柱的选择、操作条件的优化、定性、定量分析,进样量和线性范围、最低检测限等实验项目进行了考察,实验结果表明此方法具有操作简单、分析速度快、分析成本低、重复性与准确性好等特点。     

PVA膜渗透汽化分离低浓度丙酮/水溶液的实验研究

采用聚乙烯醇（PVA）膜渗透汽化分离浓缩低浓度丙酮/水溶液,考察了原料液浓度、温度、膜后真空度等对PVA膜渗透通量和分离因子的影响。结果表明,随着原料液浓度的增加、温度和膜后真空度的升高,渗透通量和分离因子均呈增加的趋势,温度对渗透通量的影响基本符合Arrhenius方程。