2018, Issue 64(68), Fasc. 3 (September)

Contents

pages 1- 8    Download

Simple  and  Rapid Spectrophotometric Method for Phenol Determination in Aqueous Media

ALEXANDRA GEORGIANA APOSTICĂ, "Gheorghe Asachi" Technical University of Iași, Romania, "Cristofor Simionescu" Faculty of Chemical Engineering and Environmental Protection
TATIANA ICHIM, "Gheorghe Asachi" Technical University of Iași, Romania, "Cristofor Simionescu" Faculty of Chemical Engineering and Environmental Protection
VERONICA MĂDĂLINA RADU, "Gheorghe Asachi" Technical University of Iași, Romania, "Cristofor Simionescu" Faculty of Chemical Engineering and Environmental Protection
LAURA BULGARIU, "Gheorghe Asachi" Technical University of Iași, Romania, "Cristofor Simionescu" Faculty of Chemical Engineering and Environmental Protection, lbulg@tuiasi.ro

pages 9 - 18    Download
Abstract
Simple and selective determination of phenol from aqueous media was spectrophotometrically examined using ferric chloride as colour reagent. The reaction between phenol and FeCl3 occurs rapidly (1-2 min), without to be necessary the adjustment of solution pH. The visible spectra of the purple complex, recorded against distilled water, show a maximum at 540 nm, and the absorbance remains stable for at least 10 hours. This method allows the determination of phenol from aqueous media in a relatively wide concentration range (0.09 – 2.30 mg·mL-1), with acceptable detection limits. The interferences caused by methanol, ethanol, acetone and ethylic ether were evaluated on the basis of the selectivity coefficients. The validation of the proposed method was done by recovery tests of phenol in tap water. Experimental results indicate that the proposed method allows a rapid and simple quantitative determination of phenol in aqueous media, and can be used to test the quality of industrial effluents.
Keywords: Phenol; ferric chloride; spectrophotometric method; aqueous solution; industrial applications.

A Suitable Method for Polyphenols Complexes with Copper

ROXANA-PETRONELA DAMASCHIN, "Gheorghe Asachi" Technical University of Iași, Romania, "Cristofor Simionescu" Faculty of Chemical Engineering and Environmental Protection
VALENTIN I. POPA, "Gheorghe Asachi" Technical University of Iași, Romania, "Cristofor Simionescu" Faculty of Chemical Engineering and Environmental Protection
IRINA VOLF, "Gheorghe Asachi" Technical University of Iași, Romania, "Cristofor Simionescu" Faculty of Chemical Engineering and Environmental Protection, iwolf@tuiasi.ro

pages 19 - 29    Download
Abstract
Polyphenols represent a class of natural compounds with significant bioactive attributes. One of the important property of polyphenols is the complexing of ion metals. Following this process, some complexes with impressive antioxidant properties could be obtained. The literature lists several methods considering different polyphenols, ion metals and reaction solution as well as experimental conditions including concentration, pH and temperature. This great variety of possibilities requires an analysis to establish the suitable reaction solution and the main parameters as well as their range of variation. Withal, some polyphenols model molecules have to be proposed.
Keywords: polyphenols; metal ions; complex combination; reaction solution and parameters.

Synthesis, Characterization and Biological Activity Evaluation of Some Divalent Tranzitional Metals Complexes with N-p-Nitrobenzoyl-D-L- Phenylglycine

CĂTĂLINA ROŞCA, "Gheorghe Asachi" Technical University of Iași, Romania, "Cristofor Simionescu" Faculty of Chemical Engineering and Environmental Protection
VALERIU ŞUNEL, "Alexandru Ioan Cuza" University of Iaşi, Romania, Faculty of Chemistry
MIHAELA CREŢU, "Alexandru Ioan Cuza" University of Iaşi, Romania, Faculty of Chemistry
MARIANA DIACONU,  "Gheorghe Asachi" Technical University of Iași, Romania, "Cristofor Simionescu" Faculty of Chemical Engineering and Environmental Protection
DANIEL MARECI,  "Gheorghe Asachi" Technical University of Iași, Romania, "Cristofor Simionescu" Faculty of Chemical Engineering and Environmental Protection
CARMEN MÎŢĂ, "Alexandru Ioan Cuza" University of Iaşi, Romania, Faculty of Chemistry
CORNEL STAN,  "Gheorghe Asachi" Technical University of Iași, Romania, "Cristofor Simionescu" Faculty of Chemical Engineering and Environmental Protection
GABRIELA ANTOANETA APOSTOLESCU,  "Gheorghe Asachi" Technical University of Iași, Romania, "Cristofor Simionescu" Faculty of Chemical Engineering and Environmental Protection
DANIEL SUTIMAN, "Gheorghe Asachi" Technical University of Iași, Romania, "Cristofor Simionescu" Faculty of Chemical Engineering and Environmental Protection, sutiman@ch.tuiasi.ro

pages 31- 48    Download
Abstract
This paper presents the synthesis of some Mn(II), Co(II), Ni(II) and Cu(II) complexes with N-p-nitrobenzoyl-D-L-phenylglycine (NBPG) as ligand. The characterization of the above mentioned synthesised compounds involved the structure determination by elemental analysis, FTIR spectroscopy, X-ray diffraction (XRD) and electron spin resonance (ESR). Experimental data sustain that all Mn, Co, Ni and Cu derivatives of N-p-nitrobenzoyl-D-L-phenylglycine present a crystalline structure framed orthorhombic system and are thermally stable up to temperatures above 100°C. The results of the toxicity tests on mice indicated that the lowest value of the lethal dose is displayed by the Cu complex compound. The antibacterial and antifungal activities investigations revealed that the  Co[(L)2(H2O)2] compound displays the best antibacterial properties while the Cu[(L)2(H2O)2] compound presents the best antifungal properties.
Keywords: antibacterial and antifungal activity; divalent transitional metals complexes; ESR; FTIR; N-p-nitrobenzoyl-D-L-phenylglycine; XRD.

Antimicrobial  Properties  and  Importance of Tannins for the Food Industry

ANCA MIHAELA MOCANU, "Gheorghe Asachi" Technical University of Iași, Romania, "Cristofor Simionescu" Faculty of Chemical Engineering and Environmental Protection, ancamocanu@ch.tuiasi.ro

pages 49 - 56    Download
Abstract
The present paper is aimed to perform extended studies on the tannins extracted from the green nuts with a special attention paid to the separation methods and testing of the anti-microbial activity against some gram- positive and gram-negative micro-organisms as well as against the fungi. For finding the optimum extraction method the extractions by mechanical stirring and in ultrasonic field were carried out while the polyphenolic compounds were determined by applying the spectrophotometric method. The sensitivity of micro-organisms toward the tannin compounds was tested under the optimum standard conditions. Following the antibacterial test the inhibitory action of the tannin compounds on the microorganisms under study was estimated which affords their use in food industry by adding them in various food products (cake creams, certain sausage and cheese types).
Keywords: green nuts; separation methods; microorganisms; difusimetric method; tested activity.

Effect of Surface Morphology on Cell Growth on Polyester Films Immobilized with Biomolecules

MIOARA DROBOTĂ, "Petru Poni" Institute of Macromolecular Chemistry, Iași, Romania, miamiara@icmpp.ro
GRAȚIELA PIRCALABIORU, Sanimed International Impex S.R.L, București, Romania; Research Institute of University of Bucharest, Romania
MARIA BUTNARU, Biomedical Sciences "Grigore T. Popa" University of Medicine and Pharmacy, Iași, Romania

pages 57 - 66    Download
Abstract
There are many methods to modify the surface properties of the polymer films, such as chemical, mechanical, enzymatic or physical treatments. The polyesters are frequently used to improve the adhesion of the proteins and cells due to their excellent surfaces properties. The purpose of this study was to monitoring changed surfaces in order to improved proteins anchoring on the surface. Polyethylene terephthalate (PET) was the designated polymer due its excellent properties. The surface of this polymer has been investigated regarding the interactions of the polymer surface with proteins after UV functionalization for improving the adhesion properties using methods such as FTIR spectroscopy, scanning electron microscopy (SEM), contact angle, and biocompatibility tests.
Keywords: cells; gelatine; hybrid materials; polar groups; UV functionalization.