Determination of Free Fatty Acids in Natural Oils and Alkyd Resins by High Performance Liquid Chromatography

Abstract

Mixtures of free fatty acids in natural oil and alkyd resin samples have been analyzed using a μBondapak Free Fatty Acid column in conjunction with a ternary mobile phase. Variation of the mobile phase composition allows ‘‘fingerprinting'’ as well as quantitation of the fatty acid components. Samples can be analyzed in ten minutes by this method. The results of the application of this technique to the identification of oil sources of fatty acids as well as the production of fatty acids during alkyd resin synthesis are given. Good agreement is observed for fatty acid compositions determined via HPLC with those obtained by gas chromatographic methyl ester analysis.     

高效液相色谱法测定大豆乳清中大豆低聚糖

大豆低聚糖是大豆中可溶性糖质的总称,主要成分是蔗糖(双糖)、棉子糖(三糖)、水苏糖(四糖)等.大豆低聚精对人体具有奇特的生理功效,能有效地促进人体肠道内有益菌群双歧杆菌的增殖,并且具有整肠功能.测定大豆低聚糖的方法有高效液相色谱法和气相色谱法,这两种方法都具有定性、定量分析大豆低聚糖的优点.气相色谱法采用衍生化的方法测定,具有较高的灵敏度,但操作复杂,而且进样口的高温会使糖的衍生物分解,甚至可被留在进样口的残留物所催化.高效液相色谱法可以直接测定,不必采用衍生化处理,减少了糖的损失和偶然误差,具有前处理简单、分离效果好,回收率和重现性均比气相色谱法好的优点.本文采用高效液相色法测定大豆蛋白生产过程中排放大豆乳清中的大豆低聚糖,并对测定条件及测定效果进行了探讨.     

Analysis of Free Fatty Acids on the Fingertips by High Performance Liquid Chromatography

Abstract

This investigation studied the efficiency of high performance liquid chromatography in the determination of free fatty acids present on the fingertips, and assessed the quantitative relationship between skin fatty acids and the degree of microbial contamination. Automated surgical scrub was utilized to eliminate the microbial contamination.

The high performance liquid chromatography provided excellent separation of skin fatty acids for evaluation with the bacterial counts. The fatty acid peaks identified ranged in chain length from C12 through C32. All the fatty acids evaluated showed positive correlation with the bacterial counts with the exception of one acid which had an inverse relationship but none were statistically significant. Finally, the surgical scrub chromatograms showed that the straight chain acids C19 and C21 were lower in concentration than C23 and C25; also, C26 was lower in concentration than C28 and C30.

It was evident from the data that fatty acids which have been shown to be bacteriostatic in vitro do not demonstrate the same property on the fingertips. The finding of lower concentration of C19, C21, and C26 than longer chain acids is inconsistent with simple two carbon addition, and indicates there is possible branching at these points in metabolic pathway of fatty acid synthesis.     

高效液相色谱法测定间羟基苯甲酸

用高效液相色谱法测定了间羟基苯甲酸的含量。在反相Ｃ１８柱上,用甲醇－水（ｐＨ２．５）作流动相,紫外２３０ｎｍ检测,以间甲基苯甲酸作内标定量,方法简便、可靠,变异系数为０．２５％～０．３４％。     

气相色谱－质谱法测定各种柑桔籽油中脂肪酸的含量

Five fatty acids in orange oils were separated and identified with GC/MS and 9. 12-Octadecadiexioic acidin the oils was quantitated with HPLC.     

高效液相色谱法分离测定洛伐他汀及其开环酸

改进了洛伐他汀的分析方法，以甲醇：水＝80：20为流动相，采用紫外检测器检测，使用C4色谱柱定性、定量分析了洛伐他汀及洛伐他汀羟基酸，并得出了相关方程．实验证明，采用新的色谱条件可在有效地分析洛伐他汀及其开环酸的基础上，节约分析成本．     

高效液相色谱-质谱分离鉴定荧光试剂标记的脂肪酸

以2-(2-(10-蒽基)-萘[2,3-d]咪唑)-乙基-对甲苯磺酸酯(ANITS)作为柱前衍生化试剂,在Eclipse XDB-C8色谱柱上,梯度洗脱实现了20种游离脂肪酸(FFA)衍生物的完全基线分离。90℃下在DMF溶剂中以K2CO3作催化剂,选取衍生试剂摩尔数为脂肪酸的7倍,衍生反应40min可获得稳定的荧光产物。激发和发射波长分别为250nm和512nm。采用大气压化学电离源(APCI)正离子模式,实现了油菜蜂花粉中游离脂肪酸的质谱鉴定。所有脂肪酸的线性相关系数均大于0.9999,检出限为24.76~98.79fmol。     

高效液相色谱法测定乌梅有机酸

采用Kromnsil C18为分析柱,0．0lmol／L磷酸盐缓冲溶液(pH2．7)为流动相,紫外215nm检测,建立了乌梅中草酸、酒石酸、苹果酸、乳酸、乙酸、柠檬酸、琥珀酸等多种有机酸的高效液相色谱方法。方法的回收率为98％～105％;RSD为2．26％～7．82％;检出限为10～75ng(S／N=3)。测定了4种不同产地和种类的乌梅中的苹果酸、乳酸、乙酸、柠檬酸、琥珀酸的含量。     

液晶中间体对-烷基苯甲酸的高效液相色谱测定

1　引　　言对 烷基苯甲酸在精细化工行业中有着广泛的用途 ,尤其作为液晶材料的中间体 ,对其分析测定的灵敏度和准确度显得尤为重要。气相色谱 (GC)测定有机酸时 ,常因沸点较高 ,不易汽化需要对其衍生化再进行测定。由于有机酸反应不易定量进行 ,而直接影响测定结果的准确性。高效液相色谱测定有机酸比GC法简便 ,在测定芳香族羧酸和多元酸更是如此。对烷基苯甲酸一端为烷基 ,一端为羧基 ,考虑其分子极性的特点 ,因而采用高效液相色谱 (HPLC)测定。对于同系物而言 ,由于化合物结构上的相似 ,其色谱保留值呈现出一定的规律性 ,可以依此…     

高效液相色谱法测定银杏果中有机酸的含量

建立了反相高效液相色谱测定银杏果中有机酸含量的方法.方法采用ultimate-C18色谱柱,以pH=2.0的磷酸盐缓冲溶液为流动相,流速0.5 mL/min,检测波长210 nm,在22 min内实现了7种有机酸的基线分离.有机酸的检出限在0.001～0.067μg/mL之间.所建立的方法具有分析速度快、线性范围宽、灵...     

Determination of Isocyanic Acid in Air by High Performance Liquid Chromatography

Abstract

Isocyanic acid in air is determined quantitatively by collection in a scrubber solution of N-4-nitrobenzyl-N-n-propylamine. The urea derivative, which is formed, is determined by using reverse phase high performance liquid chromatography.     

高效液相色谱法测定牙膏中的氨甲环酸

建立了丹磺酰氯柱前衍生/高效液相色谱测定牙膏中氨甲环酸(TA)的方法。牙膏经甲醇提取、氮吹至干,再用丹磺酰氯进行衍生。衍生物通过X-Bridge C18色谱柱(250 mm×4.6 mm×5μm)分离,以乙腈和0.1%甲酸水溶液为流动相梯度洗脱,在紫外波长250 nm条件下进行定量测定。系统考察了缓冲溶液p H值、衍生温度和衍生时间对氨甲环酸衍生效率的影响。结果表明,在优化实验条件下,氨甲环酸衍生物与基体杂质达到有效分离,在1~425 mg/L范围内线性关系良好,相关系数为0.999 5;在20,200,1 600 mg/kg 3个加标浓度下的回收率为98.7%~102%,相对标准偏差为0.85%~2.5%,方法检出限为2.0 mg/kg。该方法准确、可靠、灵敏度高,适用于各类牙膏中氨甲环酸的测定。     

Analyses of Polyglycehol Esters of Fatty Acids Using High Performance Liquid Chromatography

Abstract

Polyglycerol esters are important food emulsifiers available commercially as a mixture of various isonters. The need for analyses of these emulsifiers may arise at any stage of their production and use and is of significant importance from the point of view of the health authorities.

Polyglycerol esters of fatty acids can be analyzed by partition HPLC on a 25 cm column packed with 10 ym LiChrosorb Diol. The isomers were eluted gradientally with n-hexane-isopropanol mixture within 60 min. and the components monitored by uv-absorption at 220 nm.

Monoglycerol and polyglycerol monoesters as well as polyglycerol polyesters of oleic acid were separated and evaluated.     

茶叶样品中绿原酸含量的高效液相色谱法测定

建立了茶叶绿原酸含量测定的择相高效液相色谱法,采用PecosphereC18柱,以甲醇－水（体积比18：20,水中含φ＝1／61的甲酸）淋洗,用紫外检测器于326nm处测定,各组分的色谱峰达到基线分离。绿原酸在0．02－4．02μg范围内线性关系良好,线性相关系数 r＝0．9996。在安徽黄山产贡菊和安徽产金银花中加标的回收率分别为86．8％、102．0％,该法已用于十多种茶趺实际样品的测定。     

柱前衍生高效液相色谱测定小儿复方氨基酸注射液中氨基酸

建立了高效液相色谱(HPLC)测定小儿复方氨基酸注射液中各种氨基酸含量的方法.采用Kromasil C18(250×4.6 mm,5 μm)色谱柱,以2,4-二硝基氟苯为衍生试剂,梯度洗脱.流动相A为乙腈∶水(50∶50,V/V),流动相B为0.04 mol/L的磷酸二氢钾溶液(pH=6.8);流速为1.0 mL/min;检测波长为360 nm.所测氨基酸的线性范围为0.008～0.2213 mg/mL,平均回收率在97.85%～102.86%之间.     

高效液相色谱法测定丁香酸及其杂质含量

研究了一种同时测定合成粗产品中丁香酸及其３,４－二羟基－５－甲氧基苯甲酸、３,４,５－三羟基苯甲酸以及３,４,５－三甲氧基苯甲酸含量的高效液相色谱法。用ＯＤＳ－３色谱柱,流动相为甲醇／水／３６％乙酸（４０：６０：２,Ｖ／Ｖ／Ｖ）,检测波长范围为２５０～３００ｎｍ,在选定的色谱条件下,各组份１５ｍｉｎ内实现基线分离。丁香酸、３,４－二羟基－５－甲氧基苯甲酸、３,４,５－三羟基苯甲酸以及３,４,５－三     

高效液相法测定叶酸片中叶酸的含量

建立了高效液相色谱法测定叶酸片中叶酸含量的方法。采用Symmetry C18色谱柱(150×4.6mm,3.5μm),以磷酸盐缓冲溶液(PBS,pH=6.3)为流动相,检测波长254nm,柱温35℃。叶酸在0.04～0.36μg/mL范围线性良好(r=0.9999),平均加标回收率为99.4%(RSD=0.44%)。该方法简便准确,精密度良好,适用于叶酸片中叶酸含量的测定。     

高效液相色谱法测定细胞内外齐墩果酸含量

本文建立了高效液相色谱法快速准确测定A549细胞内外齐墩果酸(OA)的含量。该法采用Hypersil ODS色谱柱(250×4.6mm,5μm);流动相为pH=3.38的甲醇-水(体积比为90∶10),流速1.0mL/min,柱温30℃,检测波长210nm,进样量为20μL。结果表明,细胞内液中OA在1.020～20.40μg/mL范围内线性关系良好(r=0.9996),平均回收率为97.57%;细胞外液中OA在5.100～81.60μg/mL范围内线性关系良好(r=0.9998),平均回收率为97.37%。该方法简便易行,准确度高,重现性好,可用于A549细胞内外OA浓度的动态变化规律研究。     

大豆磷脂的高效液相色谱分析

采用正相高效液相色谱法,梯度洗脱程序和蒸发光散射检测器对大豆磷脂组成进行分析,在15min内将大豆膦脂中4种重要组分：卵磷脂,脑磷脂,肌醇磷脂和磷脂酸与其它组分完全分离,用外标法对这4种重要成分进行定量,线性范围为0．2－5．8g/L,回收率为96．7－100．8％;相对标准偏差为0．82％－1．34％,方法用于实际样品测定,获得满意的结果。