萃取-气相色谱法测定顺丁橡胶中抗氧剂264含量

摘要：用丙酮作为萃取剂,以正丁苯为内标物,采用萃取-气相色谱法测定顺丁橡胶中抗氧剂264含量。结果表明,萃取-气相色谱法操作简便、灵敏度高、分析速度快、精度高,测得的抗氧剂264含量相对偏差和相对标准偏差都小于2％,符合质量控制要求。     

宜春市茶油几种成分测定

以宜春市不同级别的茶油(精炼油和毛油)为原料,对其脂肪酸、总黄酮、类胡萝卜素成分进行分析测定。采用气相色谱-质谱联用(GC-MS)法,定性和定量分析结果表明:可鉴定出主要脂肪酸组成,并测定各脂肪酸百分含量为毛油(棕榈酸9.28%、硬脂酸1.93%、酸油79.13%、亚油酸9.42%、亚麻酸0.24%),精炼油(棕榈酸8.98%、硬脂酸2.10%、酸油80.2%、亚油酸8.66%、亚麻酸0.095%)毛油和精炼油各脂肪酸含量差别不是很大,用分光光度法测得总黄酮含量:毛油为8.557mg/100mL,精炼油为4.781mg/100mL。     

黎巴嫩雪松的化学研究:Ⅰ.黎巴嫩雪松的木材浸提物

用气相色谱与质谱研究了雪松木材的亲脂浸提物,心材浸提物含量比边材高得多。浸提物由单萜醇、单萜酮、倍半萜烯烃、倍半萜烯醇、倍半萜烯酮、双萜烃、脂肪醇、植物甾醇、脂肪酸和树脂酸等组成。氧化了的倍半萜烯、植物甾醇和脂肪酸是组分中主要     

茶油化学成分组成分析

检测茶油中不皂化物包括脂肪酸、角鲨烯、甾醇等成分的组成与含量。采用GC-MS对非皂化成分进行分析。结果显示毛油中不皂化物的含量为3.14 g/100 g,其中角鲨烯的含量占不皂化物的12.69%,在毛油中的含量为398 mg/100 g。脂肪酸分析结果表明,茶油中以油酸为主,占到了脂肪酸的76%~79%。此外还有10%左右的14-甲基十五酸、8%左右的亚油酸、2.5%左右的硬脂酸和0.3%左右的亚麻酸。     

气相色谱-质谱法分析山楂中的脂肪酸

为了促进山楂及山楂核在药物、精细化工领域的应用,用气相色谱-质谱联用仪,改良脂肪酸甲酯化法检测出山楂果肉中的7种脂肪酸,分别为棕榈酸、亚油酸、油酸、亚麻酸、硬脂酸、花生酸及山嵛酸。用CSASS软件进行峰识别及确定峰面积,峰面积归一化法计算每种脂肪酸的相对质量分数。分析测定了河北、安徽、山东、吉林、辽宁5个产地山楂药材中的脂肪酸相对质量分数,各产地去核山楂药材均以不饱和脂肪酸为主,其相对质量分数分别为59.10%、61.18%、63.08%、59.76%、60.76%。对河北、安徽、辽宁3个产地山楂核中的脂肪酸成分进行了较系统全面的研究,其脂肪酸以不饱和脂肪酸为主,相对质量分数分别为89.80%、61.59%、79.55%,均高于同一产地去核山楂中的不饱和脂肪酸相对质量分数。     

气相色谱法测定N-脂肪酰氨基酸中游离脂肪酸

建立了气相色谱法测定N-脂肪酰氨基酸中游离脂肪酸含量的分析方法。用癸二酸作为内标,样品与三氟化硼甲醇溶液反应生成甲酯化合物,以HP-5色谱柱作为分析柱,FID作为检测器,用内标法定量。结果表明,脂肪酸质量在0.08～1.28 mg/mL范围内,其峰面积与质量呈现良好线性关系,相关系数r0.999,样品加标回收率为98.1%～105%。本方法可作为肪肪酰氨基酸中游离脂肪酸的快速测定方法,适用于肪酰氨基酸的质量控制。     

气相色谱法测定γ-戊内酯的方法学研究

采用内标法进行了γ-戊内酯测定的气相色谱方法学研究。采用十二烷为内标物,对气相色谱分析γ-戊内酯的专属性、精密度、准确度、检测限等进行了验证。结果表明,气相色谱检测γ-戊内酯具有良好的线性（γ-戊内酯和内标物十二烷的浓度比（g/g）在0.25～2.5之间成线性,相关系数R2=0.9984）,重复测定相对标准偏差小于5.0%,加标回收率为99.5%~104.6%。实验表明内标气相色谱法可以用于γ-戊内酯的定量分析。     

催化氧化制备对甲氧基苯甲醛氧化液的气相色谱分析

建立了用气相色谱法分析测定对甲基苯甲醚氧化产物的方法,选用SE-30毛细管柱,以对甲基苯甲醛为内标物,在选定的条件下利用归一化法和内标法分析测定了对甲基苯甲醚、对甲氧基苯甲醛以及副产物2-溴-4-甲基苯甲醚和乙酸-4-甲氧基苄酯的含量.结果表明,各组分回收率为98.0%～103.8%,归一化法的相对标准偏差≤2.00%;内标法测定对甲基苯甲醚和目标产物对甲氧基苯甲醛的相对标准偏差≤1.00%.     

GC/MS测定高山植物油成份

本文提出用色 -质谱联用方法定性高山植物油的成份结构 ,用气相色谱法测定其含量。其中重要成份亚麻酸用内标法定量 ,方法准确、重现性好 ,变异系数小于 2 % ,回收率大于 95 %。     

气相色谱内标法测定化妆品中的甲醇和乙醇含量

建立了气相色谱内标法测定化妆品中甲醇和乙醇的方法。通过考察稀释液、内标物和气相色谱柱等条件,以N,N-二甲基甲酰胺作为稀释液,异丙醇作为内标物,选用DB-FFAP毛细管柱进行色谱分离,保留时间定性,内标法定量,并与《化妆品卫生规范》(2007版)中气相色谱顶空外标法测定甲醇的方法进行了比较。结果表明,用气相色谱内标法测定化妆品中甲醇和乙醇的含量,在0.8 mg/L～500 mg/L范围内具有良好的线性关系(R2甲醇=0.999 8和R2乙醇=0.999 7),相对误差<2.4%,回收率为92.7%～104.7%(n=6)。     

Fatty acid monoesters of 1-ascorbic acid and d-isoascorbic acid

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.     

Electrosynthesis of 2,3-dimethyltartaric acid from pyruvic acid in acid medium

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%.     

Conjugated linoleic acid production from linoleic acid by lactic acid bacteria

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.     

乳酸催化制备丙烯酸反应液中乳酸和丙烯酸含量的联合测定

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。     

由氯乙酸副产盐酸精制高纯盐酸

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     

炼厂酸性气制取硫酸生产总结

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。     

The performic acid oxidation of linoleic acid

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.     

Electrosynthesis of iminodiacetic acid from nitrilotriacetic acid

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.     

液相色谱法测定氯乙酸中乙酸、二氯乙酸的含量

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。