EXTRACTION OF TANNIN, GALLIC ACID AND PYROGALLOL FROM AQUEOUS MEDIA WITH WATER-SOLUBLE POLYMERS AND THEIR DETERMINATION IN CONCENTRATES BY THIN-LAYER CHROMATOGRAPHY

For the first time water-soluble homo- and co-polymers based on N-vinylcaprolactam and N-vinylpyrrolidone were applied for the extraction of tannin, gallic acid and pyrogallol from the aqueous-salt solutions. The distribution coefficients and the degree of extraction of phenols were established. Extraction characteristics of phenols depend on their solubility, structure, and the number of functional groups in their molecules that can form hydrogen bonds and π-complexes with polymers. The large distribution coefficients of tannin are due to its high hydrophobicity. It was established that the copolymer of N-vinylpyrrolidone with N-vinylcaprolactam shows higher extraction efficiency than homopolymers. The efficiency of extraction of the studied phenols depends on the pH of aqueous solutions. The maximum degree of extraction of phenols was achieved at pH 3. Conditions of division and determination of phenols in the polymer-aqueous concentrate using the chromatography method in a thin layer were chosen. It has been established that the selective separation of the investigated phenols is achieved using a mobile phase of 1-butanol, acetic acid and chloroform in the ratio (vol.) 4 : 1 : 5. Eluent eliminates the blur spots.  Separation time of analytes is reduced from 60 to 20-30 min in comparison with known chromatographic systems. It was established that the nature of the polymer and its presence in the concentrate does not affect the chromatographic characteristics. The technique of determination of studied substances in aqueous media was developed.Keywords: polyphenols, tannin, gallic acid, pyrogallol, extraction, chromatography, water-soluble polymers, N-vinylpyrrolidone, N-vinylcaprolactam, copolymer(Russian)DOI: http://dx.doi.org/10.15826/analitika.2015.19.3.005 P.T. Sukhanov1, A.N. Il’yin1, E.V. Churilina1, G.V. Shatalov21Voronezh State University of Engineering Technologies, Voronezh, Russian Federation2Voronezh State University, Voronezh, Russian Federatio

EXTRACTION OF TANNIN, GALLIC ACID AND PYROGALLOL FROM AQUEOUS MEDIA WITH WATER-SOLUBLE POLYMERS AND THEIR DETERMINATION IN CONCENTRATES BY THIN-LAYER CHROMATOGRAPHY

For the first time water-soluble homo- and co-polymers based on N-vinylcaprolactam and N-vinylpyrrolidone were applied for the extraction of tannin, gallic acid and pyrogallol from the aqueous-salt solutions. The distribution coefficients and the degree of extraction of phenols were established. Extraction characteristics of phenols depend on their solubility, structure, and the number of functional groups in their molecules that can form hydrogen bonds and π-complexes with polymers. The large distribution coefficients of tannin are due to its high hydrophobicity. It was established that the copolymer of N-vinylpyrrolidone with N-vinylcaprolactam shows higher extraction efficiency than homopolymers. The efficiency of extraction of the studied phenols depends on the pH of aqueous solutions. The maximum degree of extraction of phenols was achieved at pH 3. Conditions of division and determination of phenols in the polymer-aqueous concentrate using the chromatography method in a thin layer were chosen. It has been established that the selective separation of the investigated phenols is achieved using a mobile phase of 1-butanol, acetic acid and chloroform in the ratio (vol.) 4 : 1 : 5. Eluent eliminates the blur spots.  Separation time of analytes is reduced from 60 to 20-30 min in comparison with known chromatographic systems. It was established that the nature of the polymer and its presence in the concentrate does not affect the chromatographic characteristics. The technique of determination of studied substances in aqueous media was developed.Keywords: polyphenols, tannin, gallic acid, pyrogallol, extraction, chromatography, water-soluble polymers, N-vinylpyrrolidone, N-vinylcaprolactam, copolymer(Russian)DOI: http://dx.doi.org/10.15826/analitika.2015.19.3.005 P.T. Sukhanov1, A.N. Il’yin1, E.V. Churilina1, G.V. Shatalov21Voronezh State University of Engineering Technologies, Voronezh, Russian Federation2Voronezh State University, Voronezh, Russian Federatio

Extraction of tannin, gallic acid and pyrogallol from aqueous media with water-soluble polymers and their determination in concentrates by thin-layer chromatography

Для экстракции танина, галловой кислоты и пирогаллола из водно-солевых растворов впервые применены водорастворимые гомо- и сополимеры на основе N-винилкапролактама и N-винилпирролидона. Установлены коэффициенты распределения и степень извлечения фенолов. Экстракционные характеристики фенолов зависят от их растворимости, строения, числа функциональных групп в их молекулах, способных образовывать водородные связи и π-комплексы с полимерами. Большие коэффициенты распределения таннина обусловлены его высокой гидрофобностью. Установлено, что сополимер N-винилпирролидона и N-винилкапролактама проявляет большую экстракционную способность по сравнению с гомополимерами. Эффективность экстракции исследуемых фенолов зависит от рН раствора. Максимальная степень извлечения фенолов достигается при рН = 3. Обоснованы условия разделения и определения фенолов в полимерно-водном концентрате методом хроматографии в тонком слое. Селективное разделение исследуемых фенолов проводили с применением подвижной фазы, состоящей из бутанола-1, уксусной кислоты и хлороформа в соотношении (об.) 4 : 1 : 5. Элюент исключает размывание пятен. По сравнению с известными хроматографическими системами время разделения аналитов уменьшается с 60 до 20-30 минут. Установлено, что природа полимера и его присутствие в концентрате не влияет на хроматографические характеристики. Разработан способ определения исследуемых веществ в водных средах.For the first time water-soluble homo- and co-polymers based on N-vinylcaprolactam and N-vinylpyrrolidone were applied for the extraction of tannin, gallic acid and pyrogallol from the aqueous-salt solutions. The distribution coefficients and the degree of extraction of phenols were established. Extraction characteristics of phenols depend on their solubility, structure, and the number of functional groups in their molecules that can form hydrogen bonds and π-complexes with polymers. The large distribution coefficients of tannin are due to its high hydrophobicity. It was established that the copolymer of N-vinylpyrrolidone with N-vinylcaprolactam shows higher extraction efficiency than homopolymers. The efficiency of extraction of the studied phenols depends on the pH of aqueous solutions. The maximum degree of extraction of phenols was achieved at pH 3. Conditions of division and determination of phenols in the polymer-aqueous concentrate using the chromatography method in a thin layer were chosen. It has been established that the selective separation of the investigated phenols is achieved using a mobile phase of 1-butanol, acetic acid and chloroform in the ratio (vol.) 4 : 1 : 5. Eluent eliminates the blur spots. Separation time of analytes is reduced from 60 to 20-30 min in comparison with known chromatographic systems. It was established that the nature of the polymer and its presence in the concentrate does not affect the chromatographic characteristics. The technique of determination of studied substances in aqueous media was developed

EXTRACTION AND SORPTION BENZOIC ACID FROM AQUEOUS SOLUTIONS OF POLYMERS BASED ON N-VINYLAMIDES

The widespread use of aromatic acids (benzoic acid, salicylic) as preservatives necessitates their qualitative and quantitative determination in food. Effective and common way to separation and concentration of aromatic acids liquid extraction. Biphasic system of water-soluble polymers based on (poly-N-vinyl pyrrolidone, and poly-N-vinylcaprolactam) satisfy the requirements of the extraction system. When sorption concentration improved definition of the metrological characteristics, comply with the requirements for sensitivity and selectivity definition appears possible, use of inexpensive and readily available analytical equipment. When studying the adsorption of benzoic acid used as a sorbent crosslinked polymer based on N-vinyl pyrrolidone, obtained by radical polymerisation of a functional monomer and crosslinker. In the extraction of benzoic acid to maximize the allocation of water and the organic phase of the polymer used salt solutions with concentrations close to saturation. Regardless of the nature of the anion salt is used as salting-out agent, aromatic acids sorption increases with the size of the cations. In the experiment the maximum recovery rate (80%) benzoic acid obtained in the PVP (0.2 weight%.) Ammonium sulphate. The dependence stepepni benzoic acid extraction from time sorption sorbent mass and the pH of the aqueous phase. To establish equilibrium in the system, for 20 minutes. The dependence of the degree of extraction of the acid pH indicates that the acid is extracted into the molecular form. The maximum adsorption is reached at pH 3,5, with its efficiency decreases symbatically reduce the amount of undissociated acid molecules in solution

Effect of temperature and salting-out agents on the sorption of nitrophenols from aqueous solutions

Sorption of nitrophenols from aqueous media by сrosslinked N-vinylpyrrolidone-based polymer in static conditions are studied depending on the pH of the solution and the nature of the nitrophenols. It has been established that a temperature and the introduction of salting-out agents influence on the sorption of nitrophenols

TWO-PHASE SYSTEMS ON THE BASIS OF POLY-NVINYLCAPROLACTAM FOR THE EXTRACTION PRECONCENTRATION OF PHENOLS FROM AQUEOUS SOLUTIONS

The extraction of phenols from water-salt solutions was performed using a water-soluble polymer (poly-N-vinylcaprolactam). The distribution coefficients, the degree of exctraction of 14 phenols, and interrelation between the exctraction characteristics and structure of distributed compounds were determined

The distribution of minerals in eluvio-iluvial horizon of agro soddy-podzolic soil

The structure of micromonoliths from eluvial horizon (EL), transitional horizon (BEL) and iluvial horizon (BT1) of agro soddy-podzolic soil developed on clay loam mantle, underlain by non-calcareous moraine was studied. The following methods were applied: microtomography, x-ray diffractometry analyses, laser diffractometry, and soil particles sedimentation method. The objects are located on the experimental field of Zelenograd stationary related to Dokuchaev Soil Science Institute (Yeldigino village, Moscow Oblast). The method of computer tomography helped to determine the zones, from which the silty and clayey fragments of transitional horizon were extracted. The method of sedimentation allowedustomark the differences in the amount of fractions with sizes 10 mm. The method of x-ray diffractometry allowed us to determine the correlation of minerals in fractions with different particles sizes and also their qualitative composition. The minimal content of the clayey fraction is set is set in the sample from the eluvial part of the profile. The maximal content was set in the sample of separated clayey material from the transitional horizon. The most significant differences in the mineralogical composition are observed in the fraction lower than 1 mm. The eluvial part of the profile is characterized by the prevailing of hydromicasand chlorite vermiculite mixed-layer minerals. The same correlation of minerals is observed within the sample of silty part from the transitional layer. The iluvial part of the profile is characterized by the decrease of compounds with rigid structure (hydromicas, chlorite vermiculite). The clayey part of the transitional horizon is characterized by the highest content of silt and mica smectite within it. The distribution of fractions of fine (1-5 mm) and medium (5-10 mm) silt and their mineralogical content is less informative in relation to the differentiation of the soil profile during the podzolization