Russian Journal of Applied Chemistry, 2009, Vol. 82, No. 4, pp. 587−591.
Pleiades Publishing, Ltd., 2009.
Original Russian Text
I.V. Gruzdev, B.M. Kondratenok, 2009, published in Zhurnal Prikladnoi Khimii, 2009, Vol. 82, No. 4, pp. 594−598.
OF SYSTEMS AND PROCESSES
Extractive Concentration of Halogen-Substituted Phenols
in Their Gas-Chromatographic Determination
in Aqueous Media
I. V. Gruzdev and B. M. Kondratenok
Institute of Biology, Komi Scientiﬁ c Center, Ural Branch, Russian Academy of Sciences,
Syktyvkar, Komi Republic, Russia
Received September 30, 2008
Abstract—Method for recovery of chlorophenols from natural and drinking water for their subsequent gas-
chromatographic determination was considered. Processes of microliquid extraction of bromo derivatives of
chlorophenols and the method for liquid extraction with intermediate concentration of these compounds in an
alkaline solution were studied.
Phenolic compounds belong to widely occurring
and foremost contaminants of natural and drinking
water. The wide occurrence of phenol and its various
substituted derivatives is due to their fairly good solubility
in water and high reactivity . Having afﬁ nity for
halogens, phenols are easily chlorinated even under
normal conditions to give highly toxic derivatives whose
maximum permissible concentrations are 0.1 to 1.0 μg
. For example, the main source of chlorophenols
found in drinking water is the chlorination of phenol in
the stage of water disinfection .
Chlorophenols present in drinking water are
particularly hazardous because they are direct precursors
of polychlorinated dibenzo-p-dioxins, which can be
formed via chemical interaction of any two molecules
of chlorinated phenols .
An obligatory stage of the analytical cycle in
determination of phenolic compounds in aqueous solutions
by gas chromatography is the extractive concentration
. This procedure is intended for replacing the
aqueous matrix with an organic one, which is more
convenient in further instrumental analysis, for raising
the concentrations of the compounds to be determined,
and for separating interfering components. Together
with sorption, the liquid extraction belongs to the most
widely used methods for concentration of phenolic
compounds in their quantitative gas-chromatographic
In the conventional variant, this procedure involves
extraction at low phase ratios r = 10–100, where r =
, and V
are the equilibrium volumes of
the aqueous and organic phases (cm
For additional concentration, the extract volume is
diminished by evaporating the extractive agent in a ﬂ ow
of an inert gas. As a rule, this leads to distortion of the
qualitative and quantitative composition of a sample
being analyzed because of the loss of substances being
determined and concentration of impurities contained in
the extractive agent .
It was found that, in a 5–10-fold evaporation
of hexane extracts of halogen-substituted phenols
in a ﬂ ow of nitrogen, the loss of compounds being
analyzed reaches a value of 20–30%. In addition, the
concentration ratios of the substances being determined
are strongly distorted relative to those in the starting
extract (Fig. 1).
In this study, it is suggested to employ alternative
methods for extractive concentration of halogen-
substituted phenols from aqueous media: microliquid
extraction (MLE) with high phase ratios r = 500–2000
and liquid extraction with re-extraction (LE/RE).