Showing papers in "Journal of Chromatographic Science in 1976"
TL;DR: It has been demonstrated that carbohydrate bonded supports may be used in the chromatography of proteins, nucleic acids, and polysaccharides.
Abstract: Glycerolpropylsilane bonded phases have been found to control the adsorption and/or denaturation of proteins and nucleic acids on controlled porosity glass supports. The bonded-phase thickness is 18-19A while the amount of glycerol moiety varies from 80 to 150 mumoles/g depending on support pore diameter. It has been demonstrated that carbohydrate bonded supports may be used in the chromatography of proteins, nucleic acids, and polysaccharides.
280 citations
98 citations
TL;DR: In this paper, a systematic approach for the use of elution chromatography measurements in characterizing polymeric adsorbents is described, in terms of a wide range of sampling situations as well as those specific systems which have been investigated.
Abstract: : A systematic approach for the use of elution chromatography measurements in characterizing polymeric adsorbents is described. A variety of commercially available porous polymeric adsorbents has been evaluated with regard to the chromatographic capacities and efficiencies of the polymers for several organic adsorbates. The results of this work are discussed in terms of a wide range of sampling situations as well as those specific systems which have been investigated.
89 citations
TL;DR: GC-MS has been applied to the characterization of mixtures of polyunsaturated fatty acids by way of their isopropylidene, alkylboronate, methyl ether, and trimethylsilyl ether derivatives and proved to yield all information necessary for determination of chain length as well as numbers and positions of double bonds of polyun saturated fatty acids.
Abstract: GC-MS has been applied to the characterization of mixtures of polyunsaturated fatty acids by way of their isopropylidene, alkylboronate, methyl ether, and trimethylsilyl ether derivatives. In our studies we found a convenient and efficient method for the oxidation of mixtures of polyunsaturated fatty acid methyl esters by osmium tetroxide. The resulting polyhdroxy compounds are easily converted into apolar derivatives for gas chromatographic separation. The mass spectra of these individual compounds were recorded as to their usefulness for complete structure elucidation. Only the trimethylsilyl ethers proved to yield all information necessary for determination of chain length as well as numbers and positions of double bonds of polyunsaturated fatty acids.
66 citations
64 citations
62 citations
TL;DR: In the first part, the reasons for the choice of Carbowax 20M-terephthalic acid as a liquid phase are indicated and the technique for preparation of columns is descirbed and examples of chromatograms are given.
Abstract: In the first part, the reasons for the choice of Carbowax 20M-terephthalic acid as a liquid phase are indicated and the technique for preparation of columns is descirbed. The ECL of 14 to 24 carbon fatty acids (branched and positional isomers of unsaturated acids) as well as the accuracy of determination of some fatty acids, are presented. In the second part, examples of chromatograms are given as well as tables concerning the composition of various fats: vegetable oils, depot fats, and fats from organs of monogastric species, polygastric species, and fish.
60 citations
56 citations
48 citations
47 citations
TL;DR: The basic intent of the discussion is to warn environmental scientists, who use the ECD and FPD, that significant errors can occur in their results unless they adhere to the analytical requirements of the analysis.
Abstract: This paper reviews the use of electron capture and flame photometric detectors in ambient air measurements, with particular emphasis on the factors which may affect the sensitivity, precision, and accuracy of the analyses. The interference effects of oxygen, water, and other common constituents in air samples are discussed. In addition to those anomalies that are due to the nature of the analytical samples, certain limitations are imposed by the inherent response characteristics of the detectors. These notable difficulties and limitations are defined along with their potential consequences in atmospheric applications. The basic intent of the discussion is to warn environmental scientists, who use the ECD and FPD, that significant errors can occur in their results unless they adhere to the analytical requirements of the analysis. Therefore, it is necessary to validate the ECD and FPD measurement techniques for their appropriateness in each new analytical application.
TL;DR: The nonhydroxy fatty acid composition of rat brain lipids (except gangliosides) was determined by support-coated open-tubular (SCOT) gas chromatography by finding the most abundant polyunsaturated fatty acid was 22:6omega-3.
Abstract: The nonhydroxy fatty acid composition of rat brain lipids (except gangliosides) was determined by support-coated open-tubular (SCOT) gas chromatography. Fatty acids of both odd and even chain lengths ranging from C14 to C26 were detected. Brain lipids contained 49% saturated, 29% monounsaturated, and 22% polyunsaturated fatty acids. Monoenoic fatty acids were mainly of the omega-9 and omega-7 series with minor amounts of omega-10 and amega-11 isomers. Dienes and trienes consisted of omega-6, amega-7, and omega-9 series. Tetraenes were of the omega-6 series. Small amounts of omega-6 and omega-3 pentaenes were detected. The most abundant polyunsaturated fatty acid was 22:6omega-3. The advantages of support-coated open-tubular columns over wall-coated open-tubular columns for the analysis of brain lipid fatty acids are discussed.
TL;DR: Reasonable cost, simplicity of preparation and usage, and good chemical and physical stability render the silver halide phases applicable in routine analysis and quite competitive with many commercially available chemically bonded stationary phases.
Abstract: The use of silver halide impregnated supports for high-pressure liquid chromatographic (HPLC) and thin-layer chromatographic (TLC) analysis of drug substances has been studied. Successful separations of xanthines and mixtures containing barbiturates, xanthines, ergot alkaloids, and tropane alkaloids have been achieved with isocratic conditions or by using simple gradients. The Ag-supports show a similar behavior as many chemically bonded stationary phases, such as modification fo adsorption sites on silica gel to give lower retention but better specificity; rapid reconditioning in connection with gradient elution (3-5 minutes). Reasonable cost, simplicity of preparation and usage, and good chemical and physical stability render the silver halide phases applicable in routine analysis and quite competitive with many commercially available chemically bonded stationary phases.
TL;DR: Although, in this review, emphasis has been placed on monoethylenic isomers, most of the techniques described are also applicable in the study of polyenoic isomers.
Abstract: Chromatographic procedures for the determination of geometric and positional monoethylenic fatty-acid isomers in fats and oils have been reviewed. For the determination of these isomers, the procedure involving prep GLC isolation of the monoethylenic ester fractions on polar stationary phases, further separation and determination of geometric isomers by prep Ag+/TLC, and determination of positional isomers by reductive ozonolysis, is considered to be the most suitable for the analysis of a wide range of oils. Although, in this review, emphasis has been placed on monoethylenic isomers, most of the techniques described are also applicable in the study of polyenoic isomers.
TL;DR: Studies have indicated several estrogen derivatives can be rapidly formed and then separated on the same column, providing a useful qualitative analysis scheme.
Abstract: A high-pressure, normal-phase partition chromatographic method for the identification and determination of conjugated and esterified estrogens in pharmaceutical tablet dosage forms is described. The method is based on the separation of the estrogen sulfate esters on a conventional diatomaceous earth-H20 column, followed by HCI-methanol hydrolysis, and finally a chromatographic separation on a chemically bonded ether (ETH-Permaphase) column and measurement. Mobile phases found useful were combinations of 2-propanol and n-heptane. Equillin and -dehydroestrone, a structurally related isomer, not separately determined in the proposed method, are determined as a sum by performing a chromatographic study of their corresponding 2, 4-dinitrophenylhydrazine derivatives. Studies have indicated several estrogen derivatives can be rapidly formed and then separated on the same column, providing a useful qualitative analysis scheme. Commercial tablet dosage forms were analyzed for conjugated and esterified estrogens and the results are presented.
TL;DR: Twenty-six hydrocarbons were identified in the essential oil of black pepper, three of which are sesquiterpenes which have not been reported previously as occurring in this oil (beta-cubebene, alpha-guaiene and gamma-cadinene).
Abstract: Twenty-six hydrocarbons were identified in the essential oil of black pepper. Three of these are sesquiterpenes which have not been reported previously as occurring in this oil (beta-cubebene, alpha-guaiene and gamma-cadinene). Some other hydrocarbon constituents mentioned in the literature were absent in our pepper oil.