2. ENVIRONMENTAL ChEMISTRy & TEChNOLOGy 2.1. Lectures

Chem. Listy, 102, s265–s1311 (2008) Environmental Chemistry & Technology
Fig. 2. Schematic representation of the IC system configuration
used for simultaneous analysis of cations and anions
standard solution (fluoride, chloride, nitrite, bromide, nitrate,
phosphate and sulphate – Fig. 3.) and for all six cations
(lithium, sodium, ammonium, potassium, magnesium and
calcium – Fig. 4.), all peaks being baseline separated.
Fig. 3. Separation for a standard mixture of anions (Allsep
Anion 7u column, using as mobile phase a 4-hidroxybenzoic acid
4mM solution with ph-ul adjusted to 7.5 with LiOh 0.1M, the
flow rate being 0.85 ml min –1 )
Fig. 4. Separation for a standard mixture of cations (universal
Cation 7u column, using as mobile phase a 3 mM hNO3 solution,
the flow rate being 0.5 ml min –1 )
A LGC certified reference material (LGC6020, SPS
ww2) was used for validation.
Results
Calibrations were achieved using five levels of concentration,
for accurately determine the concentration of target
ions. The calibration curves show a good linearity with
R > 0.99 as indicated in Table I, Figs. 5. and 6.
s442
Table I
Results of regression analysis for calibrations
Anion
Linearity
range [ppm]
Regression equation R
F – 4.02–20.10 C = 0.000130278A + 0.83973 0.9978
Cl – 20.40–102.00 C = 0.000117938A – 0.523926 0.9997
nO 2– 20.20–101.00 C = 0.000156194A + 0.11461 0.9997
Br – 20.00–100.00 C = 0.000230581A + 1.34467 0.9995
nO 3– 20.00–100.00 C = 0.000214872A + 0.28929 0.9999
PO 4 3– 40.00–200.00 C = 0.00023591A – 0.68846 0.9994
SO 4 2– 9.94–79.52 C = 0.0001677A – 1.1364 0.9994
Li + 0.99–4.99 C = 0.00000262A – 0.7806 0.9993
na + 4.06–20.30 C = 0.000015644A – 2.12366 0.9997
nH 4 + 10.30–50.60 C = 0.000015822A + 1.04561 0.9999
K + 5.02–25.10 C = 0.000000898A + 0.62187 0.9997
Ca 2+ 5.04–25.20 C = 0.000000475A + 0.41618 0.9998
Mg 2+ 10.18–50.90 C = 0.000011512A + 1.09553 0.9998
Fig. 5. Calibrations for the reported anions