2. ENVIRONMENTAL ChEMISTRy & TEChNOLOGy 2.1. Lectures

Chem. Listy, 102, s265–s1311 (2008) Environmental Chemistry & Technology
P55 SIMuLTANEOuS ION ChROMATOGRAPhIC
DETERMINATION OF ANIONS AND CATIONS
IN SuRFACE wATERS FROM FIZES VALLEy
eDWARD MUnTEAn, TAnIA MIHăIESCU, nICOLETA
MUnTEAn and RADU MIHăIESCU
University of Agricultural Sciences and Veterinary Medicine
Cluj-Napoca, 3–5 Calea Mănăştur, 400372 – Cluj-Napoca,
Romania,
edimuntean@yahoo.com
Introduction
Water Framework Directive 11 demands a concerted
approach in order to achieve a good ecological state for all
water bodies across Europe. The objectives agreed must be
coordinated beyond the level of individual survey areas and
consolidated for the river basin district as a whole.
Fizes catchement, part of Somes catchement tributary of
Tisa watershed, is located in Transylvania Plain, in the northern
part of Romania. A distinctive feature of this area is
the presence of ponds, mainly used for fishery. The major
pollution sources are represented by sediments (generated by
erosional processes and transported in the water bodies) and
diffuse pollution sources (originated from agricultural activities
and the improper septic systems of the localities). Fizes
catchement, through its features of relatively low antropic
pressures and with little structural changes, represents a natural
laboratory for designing and implementing programs of
restorations of watersheds in agricultural landscapes.
In such a context, chemical analysis is usually employed
to identify the aquatic system characteristics including the
assessment of inputs, distribution of various chemical species
and characterization the outputs generated by the physical,
chemical and biological processes developed within the
water bodies. Among the specific chemical indicators, the
inorganic species hold an important place, determining largely
the behavior and evolution of the aquatic system.
The new analytical techniques, generated by the advent
of ion chromatography (IC) deliver a more precise measurement
of the various inorganic species present in the water
body. IC is a high-performance ion-exchange chromatography
technique for the separation and quantification of lowmolecular-weight
ions 1–8 , being in use since 1975, from the
time of the development of the eluent suppressor 6 . Because
of its high accuracy and reliability, IC is nowadays the one
of the most powerful tool for analysis of environmental samples
1,5 , becoming an important technique for the determination
of ionic species for monitoring water quality. This technique
was used for the system of fishing ponds, streams and
ground waters from Fizes Valley watershed (Fig. 1.), which
was studied in order to assess the effects of antropic pollution
through leaching of fertilizers from soils and waste waters
from the villages within its catchement.
An IC method with conductivity detection was developed,
enabling the simultaneous determination of six cations
(Li + , na + , K + , nH 4 + , Mg 2+ and Ca 2+ ) and seven anions (F – ,
s441
Cl – , Br – , nO 2 – , nO3 – , PO4 3– and SO4 2– ) in a single run, saving
thus analytical time, sample pre-treatment and reagents.
Fig. 1. Fizes catchement river network map, with sampling
points’ locations
Experimental
Chemicals for mobile phases’ preparation were of analytical
grade: 4-hidroxybenzoic acid (Acros Organics), lithium
hydroxide (Scharlau) and nitric acid (Merck). Ultrapure water
with a specific resistance of 18.2 MΩ cm –1 was utilized for
preparation of mobile phases as well as for sample dilution,
being obtained from a Direct Q 3UV Smart (Millipore). All
solutions were stored in polyethylene bottles which had been
thoroughly rinsed with ultrapure water. Mobile phases were
filtered through a 0.45 μm membrane (Millipore), and then
degassed using an Elmasonic S30 H ultrasonic bath before
use. Standard working calibration solutions were prepared
from a “six cation standard-II” (Dionex Corporation) and
from “seven cation standard-II” (Dionex Corporation). The
external standard method was used for quantification.
Water samples were collected from seven sources
located in Fizes watershed; samples were passed through a
0.45 μm membrane filter (Millipore), and then were stored
for 24 hours at 4 °C in 0.5 dm 3 polyethylene containers 9,10 ,
each sample was analyzed in triplicates. The samples with
ion concentrations exceeding the calibration range were
diluted accordingly and re-analyzed.
Analyses were performed on a Shimadzu system, consisting
from: a Proeminence DGU 20As online degasser, a
Proeminence LC-20AP solvent delivery module, an automatic
sample injector SIL-10AF, a conductivity detector CDD-
10Avp, a Proeminence CTO-20A column oven, a FCV-10AH 2
valve unit, an Allsep Anion 7u column (150 × 4.6 mm), an
Universal Cation 7u (100 × 4.6 mm) and a Proeminence
CBM-20A system controller in a configuration which is
represented schematically in Fig. 2. Instrument control, data
acquisition and data analysis were accomplished by a computer
running “LCsolution” ver.1.2. software.
300 µl samples were injected in each case; using a temperature
of 40 °C, a total separation of 23 min. was effective
for a good resolution for all seven anions from the mixed