Physicochemical properties of sorbents based on silica gel modified by 1-phenylazo-2-naphtholic complexes of transition metals

Gas chromatography sorbents based on Silokhrom C80 and modified by 1-phenylazo-2-naphtholic complexes of 3d metals (Co(II), Ni(II), Cu(II)) are obtained. Their structural, chromatographic, and sorption characteristics are investigated. It is found that modifying them with 1-phenylazo-2-naphthols of transition metals has a considerable effect on the chromatographic polarity and selectivity of sorption materials. The prospects for the practical application of the obtained sorbents are demonstrated by experiments on the gas chromatographic separation of mixtures of different classes of organic compounds

Automation of data processing and calculation of retention parameters and thermodynamic data for gas chromatography

The analyses of automation patterns is performed and the programming solution for the automation of data processing of the chromatographic data and their further information storage with a help of a software package, Mathcad and MS Excel spreadsheets, is developed. The offered approach concedes the ability of data processing algorithm modification and does not require any programming experts participation. The approach provides making a measurement of the given time and retention volumes, specific retention volumes, a measurement of differential molar free adsorption energy, and a measurement of partial molar solution enthalpies and isosteric heats of adsorption. The developed solution is focused on the appliance in a small research group and is tested on the series of some new gas chromatography sorbents. More than 20 analytes were submitted to calculation of retention parameters and thermodynamic sorption quantities. The received data are provided in the form accessible to comparative analysis, and they are able to find sorbing agents with the most profitable properties to solve some concrete analytic issues

Use of silochrome with grafted layers of transition metal acetonates for sorption concentration of volatile organic substances from aqueous media

Sorbents based on silica of Silochrome S-120 brand with covalently attached layers of transition metal acetylacetonates were synthesized. The sorption properties of the resulting chelate-containing materials were studied and the analytical potential of their application for rapid sorption concentration of volatile organic compounds from water bodies was evaluated

Determination of aliphatic acids in natural waters using distillation and solid-phase extraction

A procedure is developed and conditions are optimized for the pretreatment of natural water using distillation with no prefiltration of acidified water in combination with preconcentration by solid-phase extraction (SPE) on a Strata-X polymeric adsorbent followed by derivatization for the determination of trace concentrations of C3–C18 aliphatic carboxylic acids by gas chromatography with mass spectrometric detection. It is shown that, at the distillation stage, 90% of free carboxylic acids of the homologous series are transferred to the distillate, which greatly facilitates the procedure of the analysis of natural water containing impurity particles and humic substances and ensures the achievement of the limit of detection for the analytes about 0.05 μg/L. It is found that, at the SPE stage, the adsorbents based on copolymers of styrene, divinylbenzene, and N-vinylpyrrolidone in plastic cartridges may serve as sources of additional pollution with benzoic, palmitic, and stearic acids in the eluates under investigation

Physicochemical properties of sorbents based on silica gel modified by 1-phenylazo-2-naphtholic complexes of transition metals

Gas chromatography sorbents based on Silokhrom C80 and modified by 1-phenylazo-2-naphtholic complexes of 3d metals (Co(II), Ni(II), Cu(II)) are obtained. Their structural, chromatographic, and sorption characteristics are investigated. It is found that modifying them with 1-phenylazo-2-naphthols of transition metals has a considerable effect on the chromatographic polarity and selectivity of sorption materials. The prospects for the practical application of the obtained sorbents are demonstrated by experiments on the gas chromatographic separation of mixtures of different classes of organic compounds

Quantitative evaluation of polarity of silica gel modified with transition metals chelates for gas chromatography

New packings based on Silochrome C80 modified with Cu (II), Co (II) and Ni (II) 8-oxyquinolinates were studied. Their sorption characteristics and chromatographic properties were investigated and the comparative evaluation of sorbents polarity was carried out by applying Rohrschneider-McReynolds coefficients system, thermodynamic data and using the solvation parameter model of Abraham. It was found that the nature of metal and complex structure have a decisive influence on the physico-chemical properties of the packings. Modified silica gels show high selectivity for gas chromatographic separation of oxygen containing and aromatic organic compounds

Quantitative evaluation of polarity of silica gel modified with transition metals chelates for gas chromatography

New packings based on Silochrome C80 modified with Cu (II), Co (II) and Ni (II) 8-oxyquinolinates were studied. Their sorption characteristics and chromatographic properties were investigated and the comparative evaluation of sorbents polarity was carried out by applying Rohrschneider-McReynolds coefficients system, thermodynamic data and using the solvation parameter model of Abraham. It was found that the nature of metal and complex structure have a decisive influence on the physico-chemical properties of the packings. Modified silica gels show high selectivity for gas chromatographic separation of oxygen containing and aromatic organic compounds

Use of silochrome with grafted layers of transition metal acetonates for sorption concentration of volatile organic substances from aqueous media

Sorbents based on silica of Silochrome S-120 brand with covalently attached layers of transition metal acetylacetonates were synthesized. The sorption properties of the resulting chelate-containing materials were studied and the analytical potential of their application for rapid sorption concentration of volatile organic compounds from water bodies was evaluated

Adsorption properties of new Silochrome-based chelate-containing gas chromatographic materials

Adsorbents were obtained on the basis of Silochrome S80 modified with complex compounds of copper(II) and nickel(II) with bidentate nitrogen-containing organic ligands. The gas-chromatographic method was used to study the thermodynamic characteristics of the adsorption of organic compounds belonging to various classes on Silochrome S80 before and after its modification. It was found that supported metal complexes strongly affect the chromatographic polarity and favor a more selective separation of mixtures of close-boiling carbonyl compounds and saturated and unsaturated light hydrocarbons