The analysis of glycerol by gas chromatography

Commencai glycerol and its organic impurities can be measured accurately by a single gas Chromatographic GC analysis utilizing Tenax-GC® and flame detection.     

气相色谱法分析工业1,2-二氯丙烷

在气相色谱法分析工业1，2-二氯丙烷过程中，采用内标法消除了小体积进样产生的误差，并采用分离弱极性物质的聚乙二醇丁二酸酯和硅油Ⅲ混合固定液，6201担体为载体，长5m、内径3mm的色谱柱。将原标准样品、本方法和加入内标物后的样品分析色谱图进行了比较，认为本方法在加入内标物后的分析效果好、误差小。     

Jojoba oil analysis by high pressure liquid chromatography and gas chromatography/mass spectrometry

Two analytical procedures for determining com-positions of jojoba liquid wax esters are described and compared. One, the more tedious, involves separation of wax ester homologs by high pressure liquid chro-matography followed by determination of the acid and alcohol moieties from each homolog. The second allows rapid determination of wax ester composition by gas Chromatographic separation of hydrogenated jojoba wax esters according to chain length, followed immediately by ancillary mass spectrometric identifi-cation of the acid and alcohol moieties. Double bonds in the alkyl chains in jojoba liquid waxes were almost exclusively (98%) ω-9, when examined by gas chro-matography/mass spectrometry (GC/MS) and ozonolysis/GC/MS. Presented in part at the 2nd International Conference on Jojoba and Its Uses, Ensenada, Mexico, February, 1976.     

Rapid ethanolysis procedure for jojoba wax analysis by gas liquid chromatography

A rapid ethanolysis procedure for preparing jojoba wax for gas liquid chromatographic analysis is described. The wax esters are hydrolyzed by refluxing 4 drops of jojoba wax in 5% HCl in anhydrous ethanol in a test tube. The resulting fatty acid ethyl esters and fatty alcohols are separated and quantitated by a single gas liquid chromatographic run. Analysis of duplicate samples by this procedure gives essentially the same results as a procedure which requires 10 times more sample and reagents and considerably more time.     

Sources of error in the analysis of glucosinolates by gas liquid chromatography

A study was made of the accuracy and precision of glucosinolate determination by gas liquid chromatography (GLC) after transformation of the glucosinolates to desulfoglucosinolates and silylation. The condition of the GLC column and the cleanness of the injection port were found to be crucial for quantitative determination of the glucosinolate silyl ethers. The relative stabilities of glucosinolate silyl ethers in pyridine solution remained constant over a period of weeks in air at ambient temperature.     

Determination of plasma tocopherols by gas liquid chromatography

A method is described for the separation and determination of plasma tocopherols by gas liquid chromatography (GLC). Proteins in 0.1 g samples of plasma were precipitated with ethanol containing a known amount of 5,7-dimethyltocol which served as an internal standard. Tocopherols were extracted into petroleum ether, purified by thin layer chromatography and analyzed as trimethylsilyl ethers by gas liquid chromatography (GLC) on 0.5% Apiezon L. Recoveries of α- and γ-tocopherols averaged 100% and 93%, respectively. The mean total tocopherol content of eight human plasma samples was 8.5 μg/g by GLC and 9.9 μg/g by a ferric chloride-α,α′-dipyridyl method. The α- and γ-tocopherol contents of 16 human plasma samples ranged from 4.0 to 12.3 μg/g and 0.6 to 2.1 μg/g, respectively.     

Analysis of whole beeswax by gas liquid chromatography

Gas liquid chromatographic analysis of unfractionated beeswax (treated with diazomethane) using Dexsil 300 as liquid phase gives a good separation of hydrocarbons, free fatty acids as methyl esters, and long chain monoesters. These components can be estimated using internal standards and together account for ca. 65% of the wax. Petroleum hydrocarbon or fatty acid adulterants can be detected. Unsaturated hydrocarbons are partially resolved from the corresponding saturated compounds. Issued as NRCC No. 12775.     

气相色谱法测定氯乙酸母液

通过对氯乙酸母液生成氯乙酸乙酯的酯化条件和色谱分析条件的研究,确定了以浓 硫酸为催化剂,以三氯甲烷为萃取剂的酯化条件,并采用热导检测器,面积归一化法进行定量。     

Comparison of some commercial waxes by gas liquid chromatography

Volatile components (hydrocarbons, monoesters, free acids as methyl esters and free alcohols as acetates) of seven unhydrolyzed commercial waxes-ouricury, carnauba, Chinese insect, lac, esparto, candelilla and Japan wax—have been analyzed and compared by gas liquid chromatography. Though appreciable portions of the waxes were nonvolatile, the results were sufficient to distinguish the seven waxes completely. Methanolysis products were analyzed directly by gas liquid chromatography, and the results agreed with those previously obtained for hydrolysis products of these waxes. Ouricury wax gave 18% C₂₄−C₃₄ αω-diols and 4% C₂₄−C₃₂ ω-hydroxy acids, in addition to 28% C₂₀−C₃₂ aciods and 17% C₂₂−C₃₄ alcohols, on methanolysis. NRCC No. 13387.     

气相色谱法分析氯乙醇

介绍了采用FID的色谱仪聚乙二醇20M色谱柱对氯乙醇的定量测定方法。内标物选择正十三烷。标准偏差为0．26，变异系数0．27％，回收率为99．69％，线性相关系数为0．9996。气相色谱分析法简便、快速、准确，克服了化学分析法操作时间长、步骤复杂、误差较大的缺点，为氯乙醇生产中控及产品检测提供了一种简捷可靠的分析方法。     

Inverse gas chromatography of liquid polybutadienes

Results of inverse gas chromatography study of liquid polybutadiene and dihydroxypolybutadiene are presented. The study was motivated by the application of polybutadiene polyols in polyurethane chemistry where miscibility problems are often encountered. The experimental results revealed marked differences in interaction behavior of polybutadiene and dihydroxypolybutadiene, particularly with relation to the polar molecules. Influence of temperature is discussed as well as relation to the previous miscibility study.     

Quantitative analysis of short chain fatty acids using gas liquid chromatography

The short-chain fatty acids, propionic to pelargonic, have been analyzed by gas liquid chromatography, as their butyl, phenacyl, and decyl esters to overcome losses due to their volatility. The three methods are compared and the decyl ester procedure offers the most advantages. Presented in part at the AOCS meeting in Los Angeles, Calif., 1959. Issued as N.R.C. No. 7261. National Research Council of Canada Postdoctorate Fellow 1957–1959.     

The Conversion of 2,4-Dinitrophenylhydrazine derivatives of monocarbonyls to ethylenethioacetals and ethylenethioketals for analysis by gas liquid chromatography

A method was developed for the direct conversion of 2,4-dinitrophenylhydrazones (2,4-DNPHS) ofn-al-kanals and methylketones int ethylenethioacetals and ethylenethioketals for analysis by gas liquid chromatography (GLC). the method depended on heating the 2,4-DNPHS and 1,2-ethanedithiol with boron fluoride (BF₃) ethyl ether at 125 C for 12 min or withp-toluenesulfonic acid at 200 C for 15 min. The reaction was extracted with pentane, and after evaporation, the product was dissolved ono-cylene and injected into the GLC. High yields of above 90% were obtained from long chain 2,4-DNPHS and somewhat lower yields of about 80% were obtained from short chain 2,4-DNPHS. Eight standard ethylenethioacetals and ethylenethioketals were synthesized; their elemental analysis, bp, mp, and retention times on FFAP and SE-30 GLC columns were determined.     

Fatty acid composition of capsicum oils by gas liquid chromatography

The fatty acid composition of oils extracted from various parts (pericarp, seeds and stem) of the fruit ofCapsicum and from samples of Greek red pepper itself were obtained by gas liquid chromatography. Samples from three different varieties ofCapsicum annuum, cultivated in the region of Almopia, Greece, were taken from two crops (1967, 1968) and examined. The results are discussed. No characteristic differences in fatty acid composition of the corresponding samples of the parts ofCapsicum fruit of the three Greek varieties were noticed and there was no difference between the two crops. However, considerable differences in fatty acid composition between Greek and American varieties were observed, probably due to climatic conditions. Presented at the Association of Greek Chemists Meeting, Athens, 1970.     

用毛细管气相色谱仪分析DMC组成的方法

建立了采用毛细管气相色谱仪分析甲基环硅氧烷混合物(DMC)组成的方法。通过改变柱子类型、升温程序等，得到了测定DMC的最佳气相色谱分析条件，获得了良好的分析结果。该法具有快速、准确、精密度高的优点。     

Direct analysis of trivernolin by high-performance liquid chromatography

A rapid liquid chromatographic method for the quantitation of trivernolin in epoxy seed oils has been developed. A weighed sample of the oil is dissolved in chloroform (～100–300 mg/ml), and a 1–20µl portion of the oil is chromatographed on a 2 ft×1/4 in. OD C₁₈ µ-Bondapak column with acetonitrile-acetone (2:1, v/v). The area of the trivernolin peak from the differential refractometer recorder tracing is converted toµg trivernolin by use of a calibration curve of peak area vs. trivernolin weight.     

Determination of double bond position in unsaturated triglycerides by analysis of the oxidation products by gas liquid chromatography

Oleic, linoleic, and linolenic esters and olive, sunflower, linseed, rapeseed, hydrogenated rape-seed, and coriander oils have been oxidized by the permanganate-periodate reagent. The relative amounts of the dibasic acids and of the mono-basic acids produced were determined by gas liquid chromatography (GLC). These results were used in combination with the compositions of the oils, also found by GLC, to calculate the positions of the double bonds in the unsaturated fatty acids of the oils. Evidence for the presence of small amounts of 11-octadecenoic acid and other unusual isomers was obtained. Presented in part at the AOCS Meeting in New York, 1960. Is-sued as NRC No. 7850.     

多方位视角提高化妆品生产企业质量与监管水平

一方面通过分析我国化妆品行业现状提出化妆品行业存在政出多头、准人门槛低、生产企业多并且检测方法缺失等问题。另一方面针对化妆品行业的问题,从全过程监管、多方力量联动提高检测能力、建立安全风险监测体系、安全评估体系以及企业自律等多方面多角度出发,通过各方面有机的联合,充分整合生产企业所在地的资源,提高化妆品行业的整体水平。     

The analysis of alkyl aryl sulfonates by micro desulfonation and gas chromatography

The structural analysis of micro quantities of alkyl aryl sulfonates by presently known chemical and spectroscopic techniques has been an exceedingly difficult task. The formidable nature of such analyses is due largely to the essential nonvolatility of the sulfonates, a fact which precludes the application of gas-liquid chromatography and mass spectrometric techniques. The present paper describes an approach wherein gas chromatography is made applicable to analysis of micro quantities of sulfonates. The key to the approach is a microchemical desulfonation procedure. This process yields the parent hydrocarbon, which is volatile and hence amenable to analysis by gas-liquid chromatography and mass spectrometry. Presented in part at the Pittsburgh Conference on Analytical Chemistry and Applied Spectroscopy, 1960.     

Stereospecific analysis of triacyl-sn-glycerols by chiral high-performance liquid chromatography

A method for the stereospecific analysis of triacyl-sn-glycerols by high-performance liquid chromatography (HPLC) on a chiral column is described. Triacyl-sn-glycerols were partially degraded with ethyl magnesium bromide, and the monoacylglycerols produced were separated as 1- and 2-monoacylglycerol fractions by thin-layer chromatography on boric acid-impregnated silica gel plates. The 1-monoacylglycerols were resolved intosn-1 andsn-3 monoacylglycerol fractions by HPLC on a chiral column (Sumichiral OA-4100) after derivatization with 3,5-dinitrophenyl isocyanate. Fatty acid methyl esters obtained from the original triacyl-sn-glycerols, 1- and 2-monoacylglycerol fractions, andsn-1 andsn-3 monoacylglycerol fractions were analyzed by gas chromatography on open-tubular columns. Stereospecific acyl distributions in triacyl-sn-glycerols were calculated from the data. The acyl distributions of several oils were obtained. The method is rapid, simple and gave reproducible results.