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1.
Summary Fat-soluble fatty acid monoesters of 1-ascorbic acid (vitamin C) and d-isoascorbic acid have been prepared from lauric, myristic, palmitic, and stearic acids in 40–50 per cent yields. Evidence has been presented to show that only the primary hydroxyl group of each of the ascorbic acids has been esterified. Antioxidant properties of these esters are being studied. Preliminary tests on the esters have indicated that they may have useful properties as interfacial modifiers.  相似文献   

2.
This study reports the electrohydrodimerization of pyruvic acid to 2,3-dimethyltartaric acid in sulphuric acid medium (0.5 M H2SO4) on a lead cathode. The main products detected were lactic acid and 2,3-dimethyltartaric acid. The selectivity towards the formation of 2,3-dimethyltartaric acid was studied vs. pyruvic acid concentration in sulphuric acid solution, at −1.1 V vs. MSE. The best selectivity of 2,3-dimethyltartaric acid reached 69% for an initial concentration of 1.7 M pyruvic acid. The yield of pyruvic acid was 84%.  相似文献   

3.
Conjugated linoleic acid production from linoleic acid by lactic acid bacteria   总被引:25,自引:0,他引:25  
After screening 14 genera of lactic acid bacteria, Lactobacillus plantarum AKU 1009a was selected as a potential strain for CLA production from linoleic acid. Washed cells of L. plantarum with high levels of CLA production were obtained by cultivation in a nutrient medium with 0.06% (wt/vol) linoleic acid (cis-9,cis-12-octadecadienoic acid). Under the optimal reaction conditions with the free form of linoleic acid as the substrate, washed cells of L. plantarum produced 40 mg CLA/mL reaction mixture (33% molar yield) from 12% (wt/vol) linoleic acid in 108 h. The resulting CLA was a mixture of two CLA isomers, cis-9,trans-11 (or trans-9,cis-11)-octadecadienoic acid (CLA1, 38% of total CLA) and trans-9,trans-11-octadecadienoic acid (CLA2, 62% of total CLA), and accounted for 50% of the total FA obtained. A higher yield (80% molar yield to linoleic acid) was attained with 2.6% (wt/vol) linoleic acid as the substrate in 96 h, resulting in CLA production of 20 mg/mL reaction mixture [consisting of CLA1 (2%) and CLA2 (98%)] and accounting for 80% of total FA obtained. Most of the CLA produced was associated with the cells (ca. 380 mg CLA/g dry cells), mainly as FFA.  相似文献   

4.
以正丁醇为内标,氢火焰离子化检测器测定,建立了气相色谱法直接进样测定乳酸催化制备丙烯酸反应液中乳酸和丙烯酸含量的方法。在载气(N2)流速为30mL·min^-1,氢气流速为88mL·min^-1,空气流速为300mL·min^-1,进样器和离子室温度为160℃,柱温为150℃的10%PEG-20M(3m×3mml填充柱上能实现很好的分离。乳酸和丙烯酸测定方法的线性相关系数分别为0.9994和0.9996,相对标准偏差分别为O.74%和0.56%,平均回收率分别为97.35%-1197.60%,检出限分别为8.62mg·L^-1和1.21mg·L^-1方法简便、快速、准确。  相似文献   

5.
开发研究了氯乙酸副产盐酸的精制工艺及盐酸中有机杂质的紫外分光光度分析方法。副产盐酸经酸洗、吸收、蒸馏得高纯盐酸。中试结果表明 ,工艺合理 ,精制盐酸达到GB 32 0 - 93规定的工业用合成盐酸标准  相似文献   

6.
碟式分酸器在硫磺制酸装置中的应用   总被引:1,自引:0,他引:1  
  相似文献   

7.
介绍炼厂酸性气制硫酸装置的工艺过程。由于实供气源与设计值有较大出入,二氧化碳浓度偏高, 并且夹带烃类物质较多,使装置无法正常运行。通过对酸性气进行预处理后,一次开车成功,各项工艺指标均达到设计要求,遇酸性气流量突降时可补充适量硫磺,维持正常生产。  相似文献   

8.
The performic acid oxidation of linoleic acid has been shown to form 9,12-dihydroxy-trans-10,11-methylene-heptadecanoic acid (I) after hydrolysis of the formate ester. A sequence of reactions led to the identification of dimethyl-trans-1,2-cyclopropanedicarboxylate by gas liquid chromatography. Spectroscopic evidence is presented for thetrans geometry in I. Failure of the monoepoxide of linoleic acid to give the formate ester of I suggests the alternative that a homoallylic carbonium ion is formed directly upon attack of the peroxide reagent.  相似文献   

9.
Electrosynthesis of iminodiacetic acid from nitrilotriacetic acid   总被引:2,自引:0,他引:2  
The electrosynthesis of iminodiacetic acid by electrooxidation of nitrilotriacetic acid in undivided cells has been studied using Zn, Cu, PbO2, DSA®O2, DSA®Cl2, C, Ni and porous carbon as anodes. Results show that the synthesis is possible in both acid and basic mediums. The best results were obtained in aqueous 40% w/w sulphuric acid with porous carbon RVC-4000 as anode and SUS 316 as cathode, at 60 °C, 400 mA cm-2 and charge 95% of theoretical. Under these conditions, nitrilotriacetic acid conversion was 92%, current efficiency 80% and selectivity 85%. Loss of selectivity was due to chemical side reaction between iminodiacetic acid and HCHO electrogenerated in the electrolysis.  相似文献   

10.
提出了液相色谱法测定氯乙酸中乙酸和二氯乙酸含量的分析方法,计算出氯乙酸的含量,并与现行工业氯乙酸国标分析方法进行了比较,证明液相色谱分析方法简洁、快速,分析结果准确,在氯碱行业具有推广运用的价值。  相似文献   

11.
12.
Carroll KK 《Lipids》1966,1(3):171-175
1-14C-Oleic acid, 2-14C-erucic acid and 2-14C-nervonic acid were administered to rats by tail-vein and the distribution of radioactivity in liver lipids was determined at intervals from 15 min to 6 hr after injection. High levels of activity were found after short time intervals which were mainly associated with triglycerides in the case of oleic acid and with free fatty acids in the case of erucic acid and nervonic acid. The activity in these lipids decreased with time and was later exceeded by that in more polar lipids. In rats given erucic acid or nervonic acid, sphingolipids were more highly labelled than glycerophosphatides. Nervonic acid showed little tendency to form a complex with serum albumin and erucic acid complexed less readily than palmitic acid. Presented at the AOCS Meeting in Houston, April 1965.  相似文献   

13.
陈嘉甫 《无机盐工业》2007,39(12):31-33
在作者开发的高速反应器一步法制专用级次磷酸钠的基础上进一步将生成的次磷酸钠和副产的亚磷酸氢钙用离子膜电渗析法制成纯度更高的次磷酸及亚磷酸产品,产品质量升级,回收利用了副产亚磷酸氢钙,并减少了原料烧碱的用量。该新工艺成本低,能耗小,无三废排出,产品多样化,属循环经济、环境友好新工艺。  相似文献   

14.
采用静态阻垢法、静态挂片法、动态热水实验法,对实验室合成的环氧琥珀酸/丙烯酸/磺酸共聚物的缓蚀、阻垢及耐高温性能进行了研究。结果表明,该共聚物的阻垢性能优于乙二胺四甲叉膦酸五钠、水解马来酸酐;在加药量为20 mg/L时,其缓蚀性能优于丙烯酸共聚物、聚马来酸酐、聚环氧琥珀酸,并具有一定的耐高温性能。  相似文献   

15.
Dmytro Buchnea 《Lipids》1974,9(1):55-57
Chromatography on silicic acid-boric acid columns permits detritylation of ester lipids, essentially without acyl migration, and simultaneous separation of the reaction products. Described is the preparation of the column and its application for the synthesis of diacyl-sn-glycerols and 2-acyl-1,2-propaneiols. Presented in part at the Canadian Federation of Biological Societies Annual Meeting in Toronto, June 1971.  相似文献   

16.
研究连续草酸电解还原制备乙醛酸的过程和工艺。采用一膜两室电解面积为10cm×10cm的离子膜电解槽进行连续电解实验,比较了电极材料、阳离子交换膜材料、研究了电解液流量对电流效率的影响以及电流密度、电解温度和电解时间对电解过程的影响。结果表明以铅极板作阴极、钽-铱作阳极板、NF-1型含氟磺酸阳离子交换膜时电解的效果较好,得到的优化电解条件为:电流密度1000A.m-2,电解温度25℃,电解时间4.5h,阴极液和阳极液流量均为2L.min-1。在此条件下的电耗为3038.9kWh.t-1产品,研究结果可为工业化设计提供参考数据。  相似文献   

17.
综述了油酸的发展状况及制备方法,介绍了混合脂肪酸选择性加氢制反应级油酸的方法,结合市场供求状况展望了反应级油酸的前景。  相似文献   

18.
The effects of oleanolic acid (OA) and ursolic acid (UA) on the fluidity and stability of dipalmitoyl phosphatidylcholine (DPPC) liposomal membrane were monitored by measuring the fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene labeled in the liposomal membrane and the leakage of calcein from the probe-encapsulated liposomes. The experiments with the liposomes made of DPPC and OA or UA showed that OA and UA exhibited a moderate fluidity-modulating effect for the liquid-crystalline liposomal membrane, and a strong condensing effect for both crystalline and liquid-crystalline liposomal membranes. Their effects were comparable to those of cholesterol. These results suggest that their fluidity-modulating and condensing effects might have some implications in their biological functions.  相似文献   

19.
月桂酸咪唑啉硼酸酯的合成   总被引:1,自引:0,他引:1  
采用两步法合成月桂酸味唑啉硼酸酯.首先研究了月桂酸味唑噼中间体的合成.通过检测反应生成的水的量和对产物进行IR表征,确定了合成中间体的最佳工艺;然后利用这一中间体与硼酸反应,合成咪唑啉硼酸酯,用同样的研究方法考察了各因素对硼酸酯合成的影响,进而得出了硼酸酯合成的最佳工艺为:以甲苯为反应溶剂,采用分批加料的方式.咪唑啉中间体与硼酸的摩尔比大于1,反应滠度160℃,反应时间4h,反应在此条件下进行时,目标产物收率高,反应时间短.  相似文献   

20.
间硝基苯甲酸在硫酸介质中的电还原特性   总被引:2,自引:2,他引:0       下载免费PDF全文
采用循环伏安法研究了硫酸介质中电极材料、扫描速度、反应温度和添加剂等对间硝基苯甲酸(mNBA)电解还原的影响。结果表明:在该体系中最合适的阴极材料为铜电极;在电还原过程中,随着扫描速度和温度增大,mNBA电还原反应的峰电流不断增大,其电极过程受扩散控制,电还原反应伴有不可逆随后化学反应;在溶液中加入无机盐SnCl2对mNBA的电解还原有明显的助催化作用。  相似文献   

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