Russian Journal of Applied Chemistry, 2013, Vol. 86, No. 9, pp. 1376−1382.
Pleiades Publishing, Ltd., 2013.
Original Russian Text © Yu.G. Slizhov, T.N. Matveeva, T.S. Minakova, 2013, published in Zhurnal Prikladnoi Khimii, 2013, Vol. 86, No. 9, pp. 1407−1413.
Effect of Technique of Applying Layers of Metal Acetylacetonates
on Acid-Base and Chromatographic Properties of Sorbents
Yu. G. Slizhov, T. N. Matveeva, and T. S. Minakova
Tomsk State University, Tomsk, Russia
Received March 27, 2013
Abstract—A series of chromatographic sorbents, which differ by way of applying modifying chelates of acetyl-
acetone was obtained. The acid-base and chromatographic properties of sorbents with thermally and chemically
grafted layers of metal acetylacetonates were investigated. It was shown that the modiﬁ cation of the mineral sor-
bents with metal acetylacetonates leads to a change in the surface acidity, as well as to an increase in the polarity
and selectivity with respect to different classes of compounds.
The technique of chemical modiﬁ cation is one of
the methods of changing solid surfaces properties. The
injection of a modifying agent in bulk or on the surface,
the change of its nature and content allows to alter in a
necessary way the activity of solids in different chemical
and physical processes, particularly, in sorption ones .
The techniques of modiﬁ cation of a sorbent surface
with applying complex compounds of Ni(II), Fe(III),
Zn(II) with acetylacetone was used in the study.
Chromaton N (0.100–0.125 mm, Semarol Praha) and
Silipor 075 (Silipor 075, 0.125–0.160 mm, Lachema)
were selected as modiﬁ ed mineral sorbents. These
mineral sorbents have a number of advantages over
organic polymer sorbents including resistance to
mechanical, chemical, and thermal inﬂ uences.
The goal of study is to derive speciﬁ c sorbents
selective for a wide range of organic compounds for
gas chromatography by modiﬁ cation of the Chromaton
N and Silipor 075 surface with Ni(II), Fe(III), Zn(II)
chelates of acetylacetone.
Modiﬁ cation of sorbents with Ni(II), Fe(III), Zn(II)
acetylacetonates is carried out in two ways : applying
the complexes from chloroform solution and synthesis
of the acetylacetonates directly on a support surface.
A weighted portion of the metal chloride in an amount
of 10% (on term of metal) of a weight of the support was
dissolved in ethanol. The salt solution was mixed with
the solid support and the solvent was evaporated. For
ﬁ xing the metal ions on the support surface the sorbent
was heated at 110–130°C for 4 hours After the heat
treatment the support was washed with water and dried.
Sodium acetate (2.5 g) and an excess of acetylacetone
were added. After 24 h, the precipitate was ﬁ ltered,
washed with water, and dried. An amount of metal
was evaluated gravimetrically and by polarography
of washing solutions. The structure of chelates was
conﬁ rmed by IR spectra obtained in the wavenumber
range of 400–4000 cm
. The prepared columns of the
sorbent were conditioned in a stream of inert carrier
gas (He) for no less than 4 hours with increasing the
temperature from 50 to 150°C.
Altering in the surface of the original and modiﬁ ed
sorbents was monitored by changing the acid-base
properties determined by the pH measurement.
Changing pH of the sorbents powder in bidistilled water
was recorded by means of a pH meter 673M with a glass
electrode ESL 43-07 .
RESULTS AND DISCUSSIONS
Experimental data are shown in Figs. 1–3 in the form
of dependency pH
= f(τ) characterizing a different