Current state of the liquid column chromatography of coumarins

Literature information for the period 1983–1990 on the use of high-performance liquid chromatography (HPLC) in the phytochemical, biochemical, toxicological, and pharmaceutical analysis of coumarin derivatives has been generalized and systematized. Conditions for the separation of complex mixtures of coumarins are considered, and questions of the use of coumarins in the HPLC analysis of natural and synthetic organic compounds are discussed.Kemerov State Medical Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 171–188, March–April, 1993.     

Determination of rare earth elements in mineral raw materials and rare earth industry products by neutron activation analysis

To determine REE in mineral raw materials, high purity RE metals and their compounds, neutron activation analysis with extraction chromatographic REE separation has been developed. Combination of the developed RE extraction and separation procedures with subsequent -spectrometric analysis of the RE radionuclides allows to determine their content with the lower detection limit –10^–5–10^–8%. The relative standard deviation is 0.2–0.3.     

Separation of mixtures of permanent gases and light hydrocarbons on spherical carbon molecular sieves by gas-solid chromatography

Summary Experimental results are presented on the application of Carbosieve S (Supelco) and Spherocarb (Analabs) spherical carbon molecular sieves for the gas chromatographic separation of mixtures of permanent gases and C₁–C₃ hydrocarbons using a single column or two columns in series. At a programmed temperature of 35–300°C, good separation of the sample components was obtained when using helium as the carrier gas. When hydrogen was used as the carrier gas and the analysis was carried out under isothermal conditions the elution sequence of oxygen and nitrogen reversed as the temperature was increased. This behaviour was observed within a temperature range of 35–225°C for Carbosieve S, and within a temperature range of 35–300°C for Spherocarb.     

Neutron activation analysis of PbxSn1-xTe using extraction chromatography

A simple procedure of neutron activation analysis for the determination of 16 impurities in Pb_xSn_1–xTe with detection limits from 1×10^–4% for Ni and Zr to 2×10^–9% for Sc has been developed. The procedure is based on extraction chromatographic separation of impurities from the irradiated sample.     

Modeling Gas Chromatography with a Specified Temperature Dependence of Henry’s Law Constant

A derivation of the chromatographic curve equation and kinetic mechanisms that determine the diffusion broadening of chromatographic peaks are considered in detail. Being combined with the theory of adsorption in the Henry region, this work has served as a basis for the development of the MOLCHROM program for modeling the gas chromatography process. An example demonstrating the adequacy of the program and its usefulness in selecting separation conditions for complex mixtures is given.__________Translated from Zhurnal Analiticheskoi Khimii, Vol. 60, No. 7, 2005, pp. 723–728.Original Russian Text Copyright © 2005 by Prudkovskii.     

High-performance liquid chromatography of alkaloids

Literature information on the HPLC of alkaloids, including adsorption, reversed-phase, ion-exchange, ion-pair, and other variants is generalized. Results are given of the chromatographic analysis of various classes of alkaloids with an indication of the conditions of separation, and the columns used, and also of the methods of detection. The advantages and disadvantages of the HPLC variants are discussed. The review includes the literature over the last 14 years.Scientific Center for Chromatography, Institute of Chemistry and Physics of Polymers, Uzbek Academy of Sciences, Tashkent. Institute of the Chemistry of Plant Substances, Uzbek Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 595–613, September–October, 1991.     

Automation of the optimization of the separation of protamines by high-performance liquid chromatography

An automatic system for optimizing the conditions for the chromatographic separation of protamines has been developed using Nelder and Mead's modified simplex method. It is proposed to use penalty functions in order to take into account nonrigid constraints on the parameters to be optimized. The optimum conditions for the separation of the protamines from sturgeon gonads have been determined. It has been established that the greatest influence on the separation of the protamines is exerted by the concentration of the ion-pair reagent — trifluoroacetic acid. The system described permits the optimization of any chromatographic separations and the determinations to be performed thanks to the application of penalty functions to the optimization parameter.Moscow Institute of Applied Biotechnology. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 663–669, September–October, 1990.     

Structure of the products of the photoreaction of osthole

The results are given of a study of the photoreaction of osthole in chloroform and acetophenone. It has been shown that when it is irradiated in the latter solvent the cyclization characteristic for coumarins takes place at the double bonds both in the 3,4- position of the coumarin ring and in the side chain, leading to the formation of cyclobutane structures.Leningrad Sanitary-Hygienic Medical Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 165–168, March–April, 1980.     

Determination of tributyltin in sediments by hydride generation /GC/QFAAS

All steps involved in the determination of tributyltin in sediments by anhydrous acetic acid extraction, hydride generation, cold trapping, gas chromatographic separation and quartz furnace atomic absorption spectrometry are critically examined. Detection limits (1.8 ng Sn.g^–1) and reproducibility at representative concentration levels (6–12%) are satisfying for practical purposes.     

Temperature programmed gas chromatography of alcohols on cellulose tribenzoate

Summary Cellulose tribenzoate (CTB) has some desirable operational properties and special interactions with alcohols. When chromatographic separation is carried out at 150°C, the C1–C4 alcohols have enhanced retention and other alcohols are eluted rapidly. Some probe molecules were used to characterize the chromatographic behavior of CTB by calculating the adsorption enthalpy (–Ha) between the sample and stationary phase.Separation of aliphatic alcohols was successfully performed on a packed column with a support (GDX) coated with CTB and temperature programming improved the separation of these alcohols.     

Liquid chromatographic determination of nitroaromatics in water following solid phase extraction,pre-column reduction and derivatization

Summary A selective and sensitive method for determination of nitroaromatics is described. The analytes were reduced to corresponding primary amines with iron powder and then derivatized with fluram in citrate buffer to form pyrrolinones. The highly fluorescent pyrrolinones were isolated and preconcentrated by octadecylsilane solid phase extraction cartridge followed by reversed-phase, high-performance liquid chromatographic analysis. Detection was at 395–495 nm. Various aspects such as the reduction process, derivatization, solid phase extraction and chromatographic separation were optimized. Analysis time was relatively short due to a special design for successive reduction and preconcentration. Limits of detection for 3-nitrophenol, nitrobenzene, 4 and 2-nitrotoluene were less than 60, 12, 60 and 280 ng L^–1 respectively.     

Ion-exchange chromatography of areneboronic acid complexes of nucleosides and mononucleotides

Conclusions A method for the chromatographic separation of a number of nucleosides and mononucleotides has been proposed which is based on the formation of anionic complexes with m-nitrobenzeneboronic and benzeneboronic acids.All-Union Scientific-Research Vitamin Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 612–616, September–October, 1970.     

Determination of pyridate and its main metabolite CL-9673 in plant materials

Summary The application of a simple reversed-phase, HPLC-UV method for the determination of the contact herbicide pyridate and its main metabolite 3-phenyl-4-hydroxy-6-chloropyridazine-known as CL-9673-in green cereals, grains and straw is described. The method is based on a simple extraction, separation of pyridate from its metabolite, hydrolysis of pyridate to CL-9673, high-performance liquid chromatographic separation of CL-9673 in both fractions using only one reversed phase column and UV-detection.The method is sensitive down to 3 ngg^–1 CL-9673 in green plants and grain and 5ngg^–1 in straw.In the range 0.05–1.0mgkg^–1 recoveries are between 73.7% and 109% from green plants, between 77.7% and 102% from grains and between 77.3% and 87.5% from straw.     

Separation of pantothenic acid derivatives as precursors for the biosynthesis of the acetylation coenzyme by chromatography on DEAE-dellulose

The possibility of the chromatographic separation of pantothenic acid derivatives — 4-phosphopantothenate, pantethine, 4-phosphopantetheine, dephospho-CoA and CoA — on a column of DEAE-cellulose (DE-11 or Servacel DEAE 23 SH) has been studied, with their detection by radiometric, enzymatic, or spectrophotometric methods. The affinity of pantothenic acid and that of pantotheine for the ion-exchange resins used are identical. The phosphorylated derivatives of these compounds, which are eluted at higher values of a concentration gradient of lithium chloride, also have identical chromatographic characteristics. The separation of dephospho-CoA and CoA is not achieved on the chromatographic system investigated, but the elution of the fractions to free them from the retained nucleotide-containing precursors of the coenzyme can be used effectively for analytical purposes.Institute of Biochemistry, Academy of Sciences of the Belorussian SSR, Grodno. Translated from Khimiya Prirodnykh soedinenii, No. 2, pp. 258–262, March–April, 1987.     

Preparation of homogeneous protamines by the fractionation of nucleoprotamine

A new method has been developed for obtaining individual protamines which is based on the chromatographic separation of an ultrasonically treated nucleoprotamine solution. The separation of the nucleoprotamine from the gonads of the Caspian sturgeonAcipenser stellatus on CM-Sephadex G-25 led to the isolation of three fractions. Analysis showed that two fractions contained homogeneous protamine — stellins A and B. The third fraction contained nonprotamines and DNA.Moscow Technological Institute of the Meat and Dairy Industry. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 378–381, May–June, 1985.     

Modern state of the chemical study of species of the genusHypericum

This review gives complete information on the chemical study of 66 species of the genusHypericum L. In individual sections the study of various groups of substances is discussed in a historical framework. The compounds isolated are given — hypericins, flavanols and tanning substances, flavones, flavonols, xanthones, coumarins, phenolcarboxylic acids, antibiotic substances, essential-oil compositions, nonvolatile saturated hydrocarbons, and other compounds. The value of these groups of substances in the connection with the pharmacological action and the therapeutic use ofHypericum species is shown. The structural formulas of 85 isolated compounds and their distribution in the species studied are given. The chemosystematic value of individual substances for the genusHypericum and the family Guttiferae is discussed.Pharmaceutical Faculty, Sofia Medical Scademy. Leningrad Institute of Pharmaceutical Chemistry. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 185–203, March–April, 1987.     

Development of a method for analyzing volatiles from foodstuff matrices,including microextraction by demixture. Application to the analysis of grapes

This paper presents a general method for analyzing volatiles from foodstuff samples, and its application to the analysis of grapes. The method includes steam stream distillation, microextraction and chromatographic analysis, and all aspects of the analysis, including sample treatment, are discussed. Data on recovery and reproducibility are given. The method allows to prepare samples for quantitative chromatographic analysis in only one hour and to quantitate the volatiles present in the original samples at concentrations between 0.2 and 2000 mg 1^–1 with FID detection.     

The stereochemistry1 of terpenoid coumarins

Summary A transition has been effected between three series of terpenoid coumarins. A method has been proposed for establishing the type of linkage of the rings of coumarins with the bicyclofarnesyl residue according to the sign of the rotation of the compound concerned.Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 707–712, November–December, 1978. Original article submitted April 26, 1978.     

Sesquiterpene derivatives of the genusFerula

The review is devoted to a study of the sequiterpene derivatives of the plants of the genusFerula (Apiaceae). Information is given on the determination of the structure, stereochemistry, and characteristic reactions of 78 coumarins, 39 esters, and six sesquiterpene alcohols isolated from plants of the genusFerula. The possible biogenetic interrelationships and mutual transitions of the sesquiterpenes that are derivatives of aliphatic and of mono- and bicyclic hydrocarbons are discussed. Some information confirming the hypotheses made is given.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 437–466, July–August, 1979.     

Cryogenic Preconcentration of Hydrogen, Argon, Oxygen, and Nitrogen in the Gas Chromatographic Determination of Their Impurities in Volatile Inorganic Hydrides

A procedure is proposed for the cryogenic preconcentration of hydrogen, argon, oxygen, and nitrogen in the gas chromatographic determination of their impurities in volatile inorganic hydrides. It is shown that the recovery of impurity gases approaches 100%. The limits of determination of impurity gases in hydrides with the use of the proposed procedure and a helium ionization detector are 2 × 10^–6–3 × 10^–5mol %, which is 5–100 times lower than the results published previously. The results are given for the determination of hydrogen, argon, oxygen, and nitrogen in silane, germane, arsine, phosphine, hydrogen sulfide, hydrogen selenide, and ammonia samples.