Showing papers in "Journal of Chromatography A in 1969"
1,228 citations
TL;DR: A copper acetate spray reagent has been used for the quantitative densitometric thin-layer chromatography of glycolipids and phospholipids from human CNS myelin and the precision ranges between zero and ± 4.5%.
Abstract: A copper acetate spray reagent has been used for the quantitative densitometric thin-layer chromatography of glycolipids and phospholipids. The precision of the method ranges between zero and ± 4.5%. Glycolipids and phospholipids from human CNS myelin have been analyzed.
394 citations
TL;DR: Developing poly(ethylene)imine cellulose thin layers with phosphate solutions gives improved resolution of complex mixtures of nucleotides and minimizes the tailing of highly radioactive orthophosphate present in the mixtures and thus facilitates chromatographic analysis of crude acid extracts of phosphate-labeled bacteria.
Abstract: Development of poly(ethylene)imine cellulose thin layers with phosphate solutions gives improved resolution of complex mixtures of nucleotides. Phosphate development also minimizes the tailing of highly radioactive orthophosphate present in the mixtures and thus facilitates chromatographic analysis of crude acid extracts of phosphate-labeled bacteria. Conditions employing phosphate development are described which give semi-quantitative resolution of the ribonucleoside triphosphate components of such extracts after one-dimensional chromatography as well as two-dimensional systems for quantitative resolution of the major nucleotide components.
332 citations
TL;DR: Alumina, activated at 800° and partially deactivated with 5% by weight of water, was found to be the most efficient and silica columns were more effective in the separation of pesticides by differential elution.
Abstract: The use of column chromatography in the clean-up of hexane extracts of animal tissues for pesticide analysis is described, using dry, partially deactivated alumina and silica columns to remove fat and other unwanted materials. By limiting the fat loading of the columns, complete elution of organochlorine residues, free of substances interfering in gas chromatographic analysis, is achieved. Two types of alumina, of different activities, and one type of silica have been tested and the order of elution of fourteen organochlorine residues determined. Alumina, activated at 800° and partially deactivated with 5% by weight of water, was found to be the most efficient. Silica columns were more effective in the separation of pesticides by differential elution.
225 citations
TL;DR: Gas-liquid chromatography studies of direct esterification of protein amino acids to n-butyl esters have been carried out by as mentioned in this paper for protein amino acid amino acid synthesis.
Abstract: Gas-liquid chromatography studies of direct esterification of protein amino acids to n-butyl esters
212 citations
TL;DR: RM values were calculated by interpolation or extrapolation from the ranges of linearity between RM values and composition of the mobile phase and the influence of substituent groups on the RM values of the penicillins.
Abstract: The RM values of II penicillins were measured by means of a reversed-phase thin-layer chromatographic method with various concentrations of acetone in the mobile phase. RM values were calculated by interpolation or extrapolation from the ranges of linearity between RM values and composition of the mobile phase. The influence of substituent groups on the RM values of the penicillins and disagreement with Σπ values are pointed out.
194 citations
TL;DR: A rapid, simple and reproducible method for the quantitative determination of phospholipids after separation by thin layer chromatography has been described and the method was compared with the generally cited methods used for the same purpose.
Abstract: A rapid, simple and reproducible method for the quantitative determination of phospholipids after separation by thin layer chromatography has been described. The method involves spraying the developed chromatograms with 50% w/w sulphuric acid, direct mineralization at high temperature and subsequent determination of the liberated inorganic phosphate with H ahn and L uckhaus ' reagent. The range of applicability of the method is from 0.05 to 0.5 micromoles of phospholipid phosphate. the method was compared with the generally cited methods used for the same purpose.
153 citations
TL;DR: A handy method was developed, which permits the separation of labelled intermediates of plant metabolism by thin-layer chromatography on cellulose layers, which is especially suitable for experiments with large numbers of samples.
Abstract: In order to measure 14C and 32P labelled metabolic compounds obtained from incorporation experiments with various plant species a handy method was developed, which permits the separation of labelled intermediates of plant metabolism by thin-layer chromatography on cellulose layers. This method is especially suitable for experiments with large numbers of samples. A preceeding purification of the plant extracts from interfering compounds is not necessary.
137 citations
TL;DR: A rapid method for the separation and quantitation of mono- and oligosaccharides is described, based on the use of Bio-Gel P-2, minus 400 mesh, in a properly designed column with water as eluent at 65°.
Abstract: A rapid method for the separation and quantitation of mono- and oligosaccharides is described. The procedure is based on the use of Bio-Gel P-2, minus 400 mesh, in a properly designed column with water as eluent at 65°. For the colorimetric estimation of the carbohydrates the effluent is monitored by an automated analyzing system. Homologous oligosaccharides containing up to thirteen glucose units are separated within four to seven hours for analytical and preparative purposes. Separation of glucose from ribose and maltose from isomaltose has also been obtained. Quantitative calibration by peak height was performed in the range of 10 to 100 μg.
134 citations
TL;DR: Silicones can be synthesized from a variety of pure or mixed monomers on and chemically bonded to silicicic surfaces as discussed by the authors, typically to chromatographic supports The resulting materials are non-extractable, thermally stable coatings which perform well in GLC and can be used for some of the more demanding types of analysis
Abstract: Silicones can be synthesized from a variety of pure or mixed monomers on and chemically bonded to silicic surfaces — typically to chromatographic supports The resulting materials are non-extractable, thermally stable coatings, which perform well in GLC and can be used for some of the more demanding types of analysis
121 citations
TL;DR: The gas-liquid chromatographic separation of the N-trimethylsilyl TMS esters of the twenty protein amino acids was achieved after evaluation of a number of combinations of siloxane liquid phases and reaction conditions were investigated for the quantitative silylation.
Abstract: Gas-liquid chromatographic separation applied in derivatization chemistry of protein amino acids as N-trimethylsilyl /TMS/ esters
TL;DR: In this article, the identification of sesquiterpenes by gas-liquid chromatography was evaluated, and the most reproducible form of GLC data was found to be the SESQUERPene data.
Abstract: The identification of sesquiterpenes by gas-liquid chromatography is evaluated. Retention indices (obtained using sesquiterpene standards rather than n-alkanes) were found to be the most reproducible form of GLC data. Retention data for fifty-five sesquiterpenes and a number of saturated hydrocarbons obtained by hydrogenation of sesquiterpenes are reported.
TL;DR: The direct extraction in all cases and the ion-exchange technique for narcotics were sufficiently sensitive to provide detection of drug usage 24 h after last administration of drug.
Abstract: This study was undertaken to evaluate the ion-exchange paper technique and rapid direct extraction methods for obtaining drugs of abuse from urine and the subsequent identification of these drugs or metabolites by thin-layer chromatography coupled with sequential chemical reagent spraying. Recoveries from urine ± S.D. of 21.7 ± 5%, 2.4 ± 0.8% and 21 ± 1% were obtained for labeled morphine, pentobarbital and amphetamine, respectively, using the ion-exchange paper technique. With this method most narcotic analgesics could be detected at a level of 1 μg/ml urine (50 ml urine sample). The method in general was unacceptable for detecting either barbiturates, amphetamines or certain psycho-active drugs (psilocybin, glutethamide, chlorpromazine, marihuana). Percentage recoveries obtained with direct extraction from urine ± S.D. were 61 ± 4% for morphine- 14 C, 86 ± 6% for pentobarbital- 14 C, and 61 ± 21% for amphetamine- 3 H. Utilizing direct extraction methods almost all the drugs of abuse could be detected at levels ranging from 1 to 2 μg/ml of urine (15 ml of urine sample). The methods described in this report provided some specificity through differential pH extraction. The subsequent use of thin-layer chromatography and sequential spray reagents allowed identification of specific drugs or metabolites. All methods and techniques could be completed within 24 h. The direct extraction in all cases and the ion-exchange technique for narcotics were sufficiently sensitive to provide detection of drug usage 24 h after last administration of drug. Both techniques were extremely simple to perform and did not require expensive equipment thus keeping the cost of analysis at a minimum. These techniques may readily be adapted to a urine monitoring program screening for drugs of abuse, provided the limitations as described are well understood.
TL;DR: Butyl esters separation from protein amino acids, using acid washed Chromosorb W of various mesh sizes was performed in this paper, where acid washed chromosorb was used to remove the butyl ester from proteins.
Abstract: Butyl esters separation from protein amino acids, using acid washed Chromosorb W of various mesh sizes
TL;DR: A new chromatographic procedure for the separation and quantitation of human hemoglobin components is described, using columns of carboxymethyl-Sephadex G-50 and 0.05 M Tris-maleic acid buffers as developers.
Abstract: A new chromatographic procedure for the separation and quantitation of human hemoglobin components is described. The method utilizes columns of carboxymethyl-Sephadex G-50 and 0.05 M Tris-maleic acid buffers as developers; application of a simple pH gradient is preferred over stepwise elution. The procedure allows the separation of Hb-A 2 from the hemoglobins S and C, and of Hb-D 2 from the slow moving hybrid component SDα. Fetal hemoglobin is eluted in front of the normal Hb-A. The minor hemoglobins of normal red cell hemolysates were fractionated into at least four components, well separated from the major hemoglobin component. The procedure has the disadvantage of requiring several days to complete the chromatographic separations.
TL;DR: Gel filtration of urine provides a simple and rapid, yet reliable, method for the separation of lactate dehydrogenase, alkaline and acid phosphatase, leucine amino-peptidase, arylsulphatase and β-glucuronidase from interfering substances.
Abstract: Gel filtration of urine provides a simple and rapid, yet reliable, method for the separation of lactate dehydrogenase, alkaline and acid phosphatase, leucine amino-peptidase, arylsulphatase, and β-glucuronidase from interfering substances. It removes inhibitors more completely than dialysis and separates all spurious lactate dehydrogenase and alkaline phosphatase activities from the protein enzymes.
TL;DR: Using thin layers of cellulose powder and a new pair of solvent systems, forty amino acids and related compounds have been separated unambiguously on a single glass plate by two-dimensional chromatography.
Abstract: Using thin layers of cellulose powder and a new pair of solvent systems, forty amino acids and related compounds have been separated unambiguously on a single glass plate by two-dimensional chromatography. The positions of a further twenty-three compounds are also recorded.
TL;DR: In this paper, the new phases OV-1 and OV17 were compared with QF-1 in the gas chromatographic analysis of 80 methyl 5β- and 5α-cholanoates and their complete trimethylsilyl (TMSi) ethers.
Abstract: The new phases OV-1 and OV-17 are compared with QF-1 in the gas chromatographic analysis of 80 methyl 5β- and 5α-cholanoates and their complete trimethylsilyl (TMSi) ethers. The 5α-cholanoates were slower than their 5β-isomers in elution from the columns by factors of 1.22, 1.11, and 1.20 for QF-1, OV-1, and OV-17, respectively. Methyl α-muricholate can be effectively separated on OV-17 from methyl cholate; the complete TMSi ethers of deoxycholate, cholate, α-, β-, and ω-muricholates can be separated on OV-17 from the TMSi ether of hyocholate. OV-17 resembles PhSi-35 in its polarity and selectivity.
TL;DR: The procedure gives a high degree of resolution of nucleotides in tissue extracts, and eluate samples can be freed of salt and water with a minimum of manipulation, by storage at reduced pressure and room temperature over sodium hydroxide and phosphorus pentoxide.
Abstract: A procedure has been devised for the isolation of soluble tissue nucleotides by ion-exchange chromatography on 1.0 × 90 cm columns of DEAE-Sephadex A-25, acetate form, using consecutive concave concentration gradients of the volatile salt triethylammonium acetate at pH 4.7. The procedure gives a high degree of resolution of nucleotides in tissue extracts, and eluate samples can be freed of salt and water with a minimum of manipulation, by storage at reduced pressure and room temperature over sodium hydroxide and phosphorus pentoxide. The method is applicable to the analysis of extracts from a variety of tissues.
TL;DR: Quantitative gas-liquid chromatography of histidine, using N-TFA n-butyl ester derivatives and histidine converted trimethylsilyl derivative is described in this paper.
Abstract: Quantitative gas-liquid chromatography of histidine, using N-TFA n-butyl ester derivatives and histidine converted trimethylsilyl derivative
TL;DR: A simple and accurate method has been devised for the quantitative analysis of protein hydrolysates using thin-layer chromatography and the results obtained agree well with those obtained by the ∝Technicon’ Automatic Amino Acid Analyzer and with those given in the literature.
Abstract: A simple and accurate method has been devised for the quantitative analysis of protein hydrolysates using thin-layer chromatography. Ninhydrin—cadmium acetate is the staining reagent and, using reflectane densitometry, calibration graphs have been drawn for twenty-two naturally occurring amino acids. The equation of the line for each amino acid has been calculated and used for the determination of the amount of amino acid present in protein hydrolysates. The results obtained agree well with those obtained by the ∝Technicon’ Automatic Amino Acid Analyzer and with those given in the literature.
TL;DR: Different patterns of elution for grey and white matter extracts were found and the implications are discussed in relation to the chemical and physicochemical characteristics of the different proteolipids and to the receptor properties shown by some of them in grey matter.
Abstract: A method for the fractionation of proteolipids extracted from the grey and white matter, involving two successive columns of Sephadex LH-20, is described. In the first column the total lipid extract (TLE) was eluted with chloroform-methanol (19:1), and in the second, pure chloroform was followed by solvent mixtures of increasing polarity. Ether precipitated TLEs were eluted through the second column. Two fractions of proteolipids were obtained, one being eluted by a gel filtration mechanism and the other by partition chromatography. Different patterns of elution for grey and white matter extracts were found. The implications of these findings are discussed in relation to the chemical and physicochemical characteristics of the different proteolipids and to the receptor properties shown by some of them in grey matter.
TL;DR: In this paper, a description of the details of construction of an apparatus for continuous liquid-solid phase chromatography is given, and a detailed description of its operation is given in detail.
Abstract: A description is given of the details of construction of an apparatus for continuous liquid—solid phase chromatography.
TL;DR: A column was developed which separated and determined microquantities of the methyl esters of seven tricarboxylic acid cycle acids, viz. fumaric, succinic, malic, α-ketoglutaric, cis-aconitic, citric, and isocitric acid, and only glycollic, oxalic and glyoxylic acid esters, could not be separated from each other.
Abstract: A column was developed which separated and determined microquantities of the methyl esters of seven tricarboxylic acid cycle acids, viz fumaric, succinic, malic, α-ketoglutaric, cis-aconitic, citric, and isocitric acid The 2 ft × 1 4 in OD 10% Reoplex 400 on acid-washed Chromosorb W column also separated the key intermediate of the dicarboxylic acid cycle, glyoxylate, from the tricarboxylic acid cycle acids In addition, the column allowed determination of microquantities of the esters of pyruvic, lactic, glycollic, oxalic, malonic, maleic, itaconic, adipic, tartaric and acetoacetic acids Of all these acid esters, only glycollic, oxalic and glyoxylic acid esters, and itaconic and maleic acid esters, could not be separated from each other Using the dual hydrogen flame ionization detector on a Beckman GC-M, a helium flow rate of 100 ml/min and temperature programming between 50 and 200° at a rate of 5°/min, were selected as optimum conditions for the separation and determination of the acid esters Under these conditions, all seven tricarboxylic acid cycle acid esters with the exception of α-ketoglutarate and isocitrate, could be standardized down to 025 μg; α-ketoglutarate and isocitrate were standardizable to 25 μg In addition, all of the esters could be estimated in amounts as low as 01 μg, with cis-aconitate estimable to 005 μg The boron trifluoride-methanol esterification procedure was tested, and found to produce 90-100% recovery for the dimethyl esters, and 50-55% recovery for the methyl and trimethyl esters of the above-mentioned acids