气相色谱法测定汽油烃类组成分析技术的应用现状与发展

对气相色谱法测定汽油馏分烃类组成分析技术的应用现状和发展进行了系统评述。分别对高分辨毛细管气相色谱法、多维气相色谱法和溴加成结合气相色谱-原子发射光谱检测法测定汽油烃类组成的特点和存在的问题进行了讨论,并提出了一些解决方案。     

药物分析(中国期刊)

对国内药物分析在2010～2011年的主要进展进行综述。内容包括高效液相色谱法、气相色谱法、毛细管电泳法、薄层色谱法、分光光度法和其它分析方法等。另外,对高效液相色谱法和气相色谱法的前处理方法、色谱柱、固定相以及不同联用技术进行分别评述,也对各种分析方法的应用领域、发展趋势等进行简要论述。     

快速毛细管气相色谱分析白酒中的香味成分

本文建立了快速毛细管气相色谱法,在10 min内分离了白酒中的香味成分,并对其中的醇、醛、酸、酯进行定性分析,对主要呈味成分己酸乙酯进行定量分析,方法重复性好,回收率较高。与常规毛细管色谱法相比,快速毛细管气相色谱法有效地缩短了分析时间,提高了白酒的分析效率。     

茶多酚的色谱分析法

 对茶多酚的主要成分――儿茶素的色谱分析法进行了综述。重点介绍了应用最多的反相高 效液相色谱法,同时简述了平板色谱法、气相色谱法以及目前出现的新的色谱分析方法。     

非抑制型电导检测离子交换色谱法的淋洗液

分别对非抑制型电导检测阴离子交换色谱法和阳离子交换色谱法的淋洗液进行了综述,６４篇。     

药物分析(国内期刊)

对国内药物分析在2012~2013年的主要文献和进展进行评述。内容包括高效液相色谱法、气相色谱法、毛细管电泳法、薄层色谱法、分光光度法和其它分析方法等。此外,对高效液相色谱法和气相色谱法的前处理方法、色谱柱、固定相以及不同的联用技术进行分别评述,对各种分析方法的应用领域、发展趋势进行简要论述。     

药物分析（Ⅰ）

对国内药物分析在2005~2006年的主要进展进行评述。内容包括高效液相色谱法、气相色谱法、毛细管电泳法、薄层色谱法、分光光度法和其它分析方法等。另外,对高效液相色谱法和气相色谱法的不同联用技术进行分别评述。共引用文献3294篇。     

药物分析 (Ⅱ)

对国内药物分析在2005~2006年的主要进展进行评述。内容包括高效液相色谱法、气相色谱法、毛细管电泳法、薄层色谱法、分光光度法和其它分析方法等。另外,对高效液相色谱法和气相色谱法的不同联用技术进行分别评述。共引用文献3294篇。     

药物分析(Ⅱ)

对国内(不含港、澳、台地区)药物分析在2008至2009年的主要进展进行综述。内容包括高效液相色谱法、气相色谱法、毛细管电泳法、薄层色谱法、分光光度法和其它分析方法等。另外,对高效液相色谱法和气相色谱法的不同联用技术进行分别评述。共引用文献3392篇。     

药物分析(Ⅰ)

对国内(不含港、澳、台地区)药物分析在2008至2009年的主要进展进行综述。内容包括高效液相色谱法、气相色谱法、毛细管电泳法、薄层色谱法、分光光度法和其它分析方法等。另外,对高效液相色谱法和气相色谱法的不同联用技术进行分别评述。共引用文献3392篇。     

毛细管气相色谱法鉴定分析杆菌

本文利用ＯＶ－１０１熔融石英毛细管柱，对１５种标准分枝杆菌的色谱特征进行了研究，得到了特异性指纹图。并对４２株临床菌株进行了鉴别。     

Semipreparative High-Performance Liquid Chromatographic Separation of Phosphatidylcholine Molecular Species From Soybean Leaves

Abstract

An improved high-performance liquid chromatographic (HPLC) method using UV detection at 205 nm is described for the semipreparative separation of the molecular species of phosphatidylcholine (PC) from soybean leaves. the separations of PC molecular species are achieved isocratically within ca. 75 min on C 18 reversed-phase column using the mobile phase, methanol:0.1 M ammonium acetate, pH 7.4 (95:5, v/v). Five molecular species for soybean PC are identified as 18:3/18:3, 18:2/18:3, 18:2/18:2, 16:0/18:3 and 16:0/18:2.     

Characterization of mycobacterial triacylglycerols and monomeromycolyl diacylglycerols from Mycobacterium smegmatis biofilm by electrospray ionization multiple-stage and high-resolution mass spectrometry

The storage of triacylglycerols (TAGs) is essential for non-replicating persistence relevant to survival and the re-growth of mycobacteria during their exit from non-replicating state stress conditions. However, the detailed structures of this lipid family in mycobacteria largely remain unexplored. In this contribution, we describe a multiple-stage linear ion-trap mass spectrometric approach with high resolution mass spectrometry toward direct structural analysis of the TAGs, including a novel lipid subclass previously defined as monomeromycolyl diacylglycerol (MMDAG) isolated from biofilm of Mycobacterium smegmatis, a rapidly growing, non-pathogenic mycobacterium that has been used as a tool for molecular analysis of mycobacteria. Our results demonstrate that the major isomer in each of the molecular species of TAGs and MMDAGs consists of the common structure in which Δ⁹18:1- and 16:0-fatty acyl substituents are exclusively located at sn-1 and sn-2, respectively. Several isomers were found for most of the molecular species, and thus hundreds of structures are present in this lipid family. More importantly, this study revealed the structures of MMDAG, a novel subclass of TAG that has not been previously reported by direct mass spectrometric approaches.     

Assessment of fatty acids in cardiac tissue as 9-anthryldiazomethane esters by high-performance liquid chromatography.

A high-performance liquid chromatographic technique for the rapid assessment fatty acids in cardiac tissue is described. A level of 50.4 +/- 14.9 nmol fatty acids per g wet weight of rat myocardial tissue could be monitored. The content of the individual fatty acids C14:0, C16:0, C16:1, C18:0, C18:1, C18:2 and C20:4 amounted to 1.9, 13.5, 0.6, 14.4, 6.1, 6.5 and 7.2 nmol/g wet weight, respectively. A comparison of this method with a well established gas chromatographic technique yielded good agreement. In contrast with time-consuming gas chromatographic techniques, there is no need to isolate (unesterified) fatty acids from the other lipid classes with column chromatography or thin-layer chromatography, because the derivatizing reagent 9-anthryldiazomethane reacts highly specifically with fatty acids.     

Identification of six species in the new genus Cronobacter (Enterobacter sakazakii) from culture using gas chromatographic analysis of fatty acid methyl esters

Capillary GC with flame ionization detection (FID) was used to determine the cellular fatty acid (CFA) profiles of six species in the new genus Cronobacter (Enterobacter sakazakii). The six different species are C. sakazakii, C. malonaticus, C. dublinensis, C. muytjensii, C. turicensis, and C. genomospecies. For GC-FID analysis, whole cell fatty acid methyl esters (FAMEs) from cells cultured on brain heart infusion (BHI) agar at 35 degrees C for 24 h were obtained by saponification, methylation, and extraction into hexane-methyl tert-butyl ether. A data set for 57 strains of Cronobacter species was prepared using fatty acid profiles from two or three replicates prepared on different days. Major fatty acids of the Cronobacter strains evaluated in this study were straight-chain C12:0, C14:0, C16:0, and unsaturated C18:1, omega7c, summed C16:1 omega7c/C16:1 omega6c, and summed C14:0 3-OH/iso-C16:1, and C17:0 omega cyclo 7-8. The CFA profiles for the Cronobacter species are similar, but there are several fatty acids-C12:0, C14:0, C16:0, C18:1 omega7c, and summed C16:1 omega7c/ C16:1 omega6c--that differ significantly among these six species. Analysis of FAMEs from Cronobacter strains grown on BHI agar by a rapid GC-FID method is a sensitive procedure for the identification of these organisms, and this analytical method provides a procedure for the differentiation of strains from closely related Cronobacter species.     

Conductance Study of 1 : 1 19-Crown-6 Complexes with Various Mono- and Bivalent Metal Ions in Water

Formation constants (ML) of 1 : 1 19-crown-6 (19C6) complexes with mono- (M+) and bivalent metal ions (M2+) were determined in water at 25 °C by conductometry. The KML value of 19C6 for M+ and M2+ decreases in the order Rb+ K+ > Tl+ > Na+ = Ag+ > Li+ Cs+ and Pb2+ > Ba2+ > Sr2+ > Cd2+ > Ca2+, respectively. The selectivity for the neighboring alkali metal ions in the periodic table is lower for 19C6 than for 18-crown-6 (18C6) except for the case of Rb+ and Cs+. The same is true for the alkaline earth metal ions. Generally, the KML values of 19C6 with M2+ are greater than those with M+. For Na+ and the ions which are smaller in size than Na+ (Li+, Ca2+, Cd2+), the KML value is larger for 19C6 than for 18C6, but the contrary holds for all the other ions of larger sizes than Na+. The limiting ionic molar conductivity (°) of the 19C6–K+ complex in water at 25 °C was determined to be 43. Although 19C6 is larger than 18C6, the 19C6–K+ complex is much more mobile in water than the 18C6–K+ complex.     

Characterization and determination of fatty acids in fish oil using gas chromatography-mass spectrometry coupled with chemometric resolution techniques

Characterization and determination of a complex mixture of fatty acid methyl esters was performed for commercial fish oil using two-dimensional GC-MS data coupled with resolution techniques. Various principle component analysis methods such as significant factor analysis and fixed size moving window evolving factor analysis were used for the number of factors, zero concentration and selective regions. Then, the convoluted chromatograms were resolved into pure chromatograms and mass spectra using heuristic evolving latent projections (HELP) method. Fatty acids of C16:1omega7, C18:4omega3, C18:1omega11, C18:1omega9, C18:0, C20:2omega6, C20:1omega9, C22:1omega11, C22:1omega9 and C24:1omega9 were resolved an fied by using similarity searches between deconvoluted mass spectra and MS database, in different parts of total ion current chromatogram. Window target testing factor analysis is also applied for confirming the presence or absence of target analytes. The results of the present work show that combination of hyphenated chromatographic methods and resolution techniques provide a complementary method for accurate analysis of real multi-component systems such as fish oil.     

Rôle du Tween-80 utilisé dans la culture des corynébactéries cutanées (groupe JK) sur la composition en acides gras cellulaires

This study of 8 strains of cutaneous corynebacteria, including 5 strains of «JK corynebacteriaå, concerns the fatty acid composition of cells grown in the presence or not of Tween 80, which enhances their growth rate. The fatty acid methyl esters were analysed by gas-liquid chromatography. The fatty acid profile of the 8 strains agreed with the general pattern of the genus Corynebacterium, with major amounts of palmitic acid (C16:0) and oleic acid (C18:0) and with only trace amounts of 10-methyl octodecanoic acid (tuberculostearic acid). Iso and anteiso branched acids were not present. The 5 strains had high levels of stearic acid (C18:0). When cells were grown in the presence of Tween-80, the fatty acid composition was modified for all strains: their profiles showed high levels of oleic acid (C18:1) and smaller quantities of palmitoleic acid (C16:1).These results confirm the advantage of fatty acid composition for identification of Corynebacteria, and particularly for cutaneous strains, and emphasize the influence of the culture medium, especially that of Tween-80.     

Differential effects on fatty acid compositions in the liver microsomes of thyroidectomized or streptozocin induced diabetic rats.

The purpose of the present study was to locate a controversial site and to make generalizations about the effects of thyroidectomy (Tx) and streptozocin (STZ) on the distribution pattern of an individual fatty acid in microsomal fractions of the animals thus treated. The results obtained were compared with the reported data. The effects of Tx on C18:1, C18:2, and all detectable C20 and C22 species harmonized well within each species; however the effects of Tx on C16 species and C18:0 varied within each species. Meanwhile, all the effects of STZ were identical within the species, but were often in opposite directions between two adjacent species; e.g. C18:0 and C18:1. These findings strongly indicate that desaturation and elongation sites were independently affected by either Tx or STZ. The comparison suggested that controversial effects appeared in the distribution proper to species C18. Therefore, delta 9-desaturase activity in the microsomal fractions was measured, using stearoyl coenzyme A (CoA) as substrate, resulting in some partial reduction in Tx, but complete suppression in STZ-treated animals. The total contents of phospholipid and cholesterol in the microsomes were also measured. Results showed a significant increase in microsomes within the STZ-group, but almost no change in the Tx-group, indicating that the changes in an individual fatty acid component and in the total fatty acids do not always take place in parallel.     

Marine Diatom, Navicula sp. Strain JPCC DA0580 and Marine Green Alga, Chlorella sp. Strain NKG400014 as Potential Sources for Biodiesel Production

Marine diatom, strain JPCC DA0580, and marine green microalga strain NKG400014 were selected as high neutral lipid-producers from marine microalgal culture collection toward biodiesel production. These strains were tentatively identified as Navicula sp. and Chlorella sp., respectively, by 18S rDNA analysis. Growth and lipid accumulation conditions of both strains were analyzed by changing nutrient concentrations in growth media and initial illuminance intensity. The highest productivity of fatty acid methyl ester (FAME) reached to 154 mg/L/week for NKG400014 and 185 mg/L/week for JPCC DA0580. Gas chromatography/mass spectrometry analysis indicates that FAME fraction from NKG400014 mainly contained 9-12-15-octadecatrienoate (C18:3) and that from JPCC DA0580 mainly contained methyl palmitate (C16:0) and methyl palmitoleate (C16:1). Furthermore, calorimetric analysis revealed that the energy content of strain was 4,233?±?55 kcal/kg (i.e., 15.9?±?0.2 MJ/kg) for NKG400014 and 6,423?±?139 kcal/mg (i.e., 26.9?±?0.6 MJ/kg) for JPCC DA0580, respectively. The value from JPCC DA0580 was equivalent to that of coal. The strains NKG400014 and JPCC DA0580 will become a promising resource that can grow as dominant species in the open ocean toward production of both liquid and solid biofuels.