2016, Issue 62(66), Fasc. 2 (June)
Contents
pages 1- 8 Download
Spectrophotometric Determination of Cu(II), Co(II) and Ni(II) Ions in Mono and Multi-Component Systems
VLADISLAV FORNEA, "Gheorghe Asachi" Technical University of
Iaşi, Faculty of Chemical Engineering and Environmental Protection
ŞTEFAN TRUPINĂ, "Gheorghe Asachi" Technical
University of Iaşi, Faculty of Chemical Engineering and Environmental
Protection
ALEXANDRU VASILICĂ IOSUB, "Gheorghe Asachi"
Technical University of Iaşi, Faculty of Chemical Engineering and
Environmental Protection
LAURA
BULGARIU, "Gheorghe Asachi" Technical University of Iaşi,
Faculty of Chemical Engineering and Environmental Protection,
lbulg@ch.tuiasi.ro
pages 9 - 20 Download
Abstract
The selective determination of Cu(II), Co(II) and Ni(II) ions
from aqueous solution was spectrophotmetrically investigated using rubeanic
acid as color reagent. The reaction between Cu(II), Co(II) and Ni(II) ions
with rubeanic acid occurs rapidly at pH 3.5 in case of Cu(II) ions and at pH
9.0 in case of Co(II) and Ni(II) ions (buffered solutions). The metal
complexes have absorption maximums at different wavelength (380 nm for
Cu(II), 480 nm for Co(II) and 590 nm for Ni(II), respectively) and this
characteristic underlies the possibility of their determination in
multi-components systems. This method allows the determination of these
metal ions in a relatively wide concentration range, with acceptable
detection limits. The interferences caused by each metal ion in the
determination of the other were evaluated on the basis of the selectivity
coefficients. The validation of Cu(II), Co(II) and Ni(II) determination
through this method was done by recovery tests of metal ions in tap water.
The obtained results shows that this spectrophotometric method can be
successfully used for the analysis of Cu(II), Co(II) and Ni(II) ions in
water samples, whether are in mono- or multi-components systems.
Keywords: metal ions; rubeanic acid; aqueous solution; spectrophotometric
method.
Determination of Mineral Acids Concentration from Mixtures by Condutometric Titration
MONICA-MARIA ROMAN, "Gheorghe Asachi" Technical University
of Iaşi, Faculty of Chemical Engineering and Environmental Protection
IONELA CIURDEA, "Gheorghe Asachi" Technical University
of Iaşi, Faculty of Chemical Engineering and Environmental Protection
CRISTINA LAZAREV, "Gheorghe Asachi" Technical
University of Iaşi, Faculty of Chemical Engineering and Environmental
Protection
LAURA BULGARIU, "Gheorghe Asachi" Technical University
of Iaşi, Faculty of Chemical Engineering and Environmental Protection,
lbulg@ch.tuiasi.ro
pages 21 - 31 Download
Abstract
In this study, a conductometric titration method is proposed for
the quantitative determination of two mineral acids (HCl and H3PO4), both
individually and from mixture. Conductometric titration assumes the
experimental measuring of electrical conductivity of the analyzed solution
as a function of added titrant volume, and depends by the concentration of
all ions present in this solution. A solution of AgNO3 (0.1 N) was used as
titrant. Both mineral acids react with AgNO3 and form low soluble compounds
(AgCl and Ag2HPO4), and these reactions are the basis of their determination
by conductometric titration. If, HCl can be analyzed in this way with high
accuracy, regardless of whether is in mixture or not, the determination
of H3PO4 acid is more difficult due to the high solubility of Ag2HPO4
precipitate. Thus, the neutralization of H3PO4 acid with NaOH (0.1 N)
solution before to start the conductometric measurements is necessary, for
that his quantitative determination to be possible. Therefore, the
conductometric titration with AgNO3 can be used for the determination of
HCl and H3PO4, both individually and from mixtures, but this is possible
only after neutralization of the mineral acids with a strong base solution.
Keywords: mineral acids; mixtures; condutometric titration; AgNO3
titrant; aqueous solution.
Analytical Methods for Analyzing Some Oils Used in Cosmetics
GABRIELA GAVRILUȚĂ, Secondary School "I. Teodoreanu" Iaşi, gavriluta.gabi@yahoo.com
pages 33 - 38 Download
Abstract
In this paper three different oils have been analysed:
sesame, olive and jasmine. For their analyses standard methods for oils and
fats described by American Oil Chemists Society (AOCS, 1993) and
pharmacopoeia assays (Brazilian pharmacopoeia, 2010), such: index of acid,
saponification, iodine, peroxides, determination of potential of hydrogen
(pH), and density. Those analyses are important because they indicate the
quality and authenticity of the oil. The results showed that the oil
extracted from sesame and olive has acceptable characteristics and is of
good quality. For all of those the saponification index, the acidity and
peroxidation value have been determined.
Keywords: index of acid; index
of saponification; index of peroxide; olive; jasmine; sesame oils.
Third Generation Biotehanol Production
ALEXANDRA CRISTINA BLAGA, "Gheorghe Asachi" Technical
University of Iași, Faculty of Chemical Engineering and Environmental
Protection
LENUȚA KLOETZER, "Gheorghe Asachi" Technical
University of Iași, Faculty of Chemical Engineering and Environmental
Protection
ALEXANDRA TUCALIUC, "Gheorghe Asachi" Technical
University of Iași, Faculty of Chemical Engineering and Environmental
Protection
DAN
CAȘCAVAL, "Gheorghe Asachi" Technical University of Iași, Faculty
of Chemical Engineering and Environmental Protection,
dancasca@tuiasi.ro
ANCA IRINA GALACTION, "Grigore T. Popa" University of
Medicine and Pharmacy, Iași, Faculty of Medical Bioengineering
pages 39 - 52 Download
Abstract
The algal biomass offers great potential as a sustainable
feedstock which can be processed for the third generation bioethanol
production, due to its many advantages: rapid growth rate, the ability to
accumulate important amounts of carbohydrates, all the materials produced
are nontoxic and biodegradable. However, in order to produce high
concentrations of ethanol, it is necessary to convert all specific
carbohydrate components of microalgae: glucan, sulphated polysaccharides,
mannitol, alginate, agar, and carrageenan. This paper describes different
types of algae and presents the main steps for the technology employed in
the production of third generation bioethanol.
Keywords: bioethanol;
continuous fermentation; microalgae; seaweed.
Graphene Obtained by Pyrolytic Decomposition in N2 Atmosphere
CĂTĂLINA NUȚESCU DUDUMAN, "Gheorghe Asachi" Technical
University of Iaşi, Department of Materials Science,
catalinanutescu@yahoo.com
JOSÉ MARÍA GÓMEZ DE SALAZAR Y CASO DE LOS
COBOS, Complutense University of Madrid, Spain, Department of
Materials Science and Metallurgical Engineering
MARÍA ISABEL BARRENA PÉREZ, Complutense University of
Madrid, Spain, Department of Materials Science and Metallurgical Engineering
LAURA GARCIA SANCHEZ, Complutense University of
Madrid, Spain, Department of Materials Science and Metallurgical Engineering
CONSUELO GÓMEZ DE
CASTRO, Complutense University of Madrid, Spain, Department of
Materials Science and Metallurgical Engineering
pages 53 - 60 Download
Abstract
Graphene, an allotrope of carbon, is study in the last years
because posed interesting chemical, optical and electrical properties. The
paper describes the graphene obtaining method by the pyrolytic
decomposition. As raw materials was used epoxy resin. The product of
pyrolytic decomposition of the epoxy resin was characterized using several
techniques: scanning electron microscopy (SEM), transmission electron
microscopy (TEM), X-Ray diffraction (XRD), Fourier Transform Infrared
Spectroscopy (FTIR). Experimental results indicate the nanostructure
stacking of multiple layers of graphene; at 500 nm we can observe lamellas
of graphene. On the base of the experimental data we can conclude that the
pyrolytic decomposition product is graphene.
Keywords: Graphene, Epoxy
resin, Pyrolysis, Characterization.
Abstract of PhD Thesis:
Extraction,
Identification and Antioxidant Activity of the Phenolic Secondary
Metabolites Isolated from the Leaves, Stems and Fruits of Two Shrubs of the
Ericaceae Family
OANA-CRINA BUJOR, "Gheorghe Asachi" Technical University of Iaşi, Faculty of Chemical Engineering and Environmental Protection, oana_crin@yahoo.com
pages 61 - 62 Download
Habilitation Thesis Summary:
Sorption - Separation Method of Chemical Compounds from Aqueous
Media
DANIELA ȘUTEU, "Gheorghe Asachi" Technical University of Iaşi, Faculty of Chemical Engineering and Environmental Protection, dsuteu@ch.tuiasi.ro
pages 63 - 68 Download