Anions in potable waters - Determination of Anions in Natural and Treated Waters - page 474

Table 7.2 Features of the simultaneous determination of pH, alkalinity and total ionic
concentration

Parameter Detection method Range of

determination a

Equation of
calibration
graph b

Repress/on
coefficient

RSd %
concentration

PH Potentiometric

(continuous
control)

3-11

Alkalinity Spectrophotometric ∆t=5.0-600µg

mL −1 CaCo 3

∆t=31.28
log C+151.5

0.9952 ±1.5(11.9µg
mL −1 )

∆S:10.0-600µm
ML −1 CaCo 3

∆S=3.48 log
C+17.3

0.9965 ±1.7 (11.9µg
mL −1 )

Concentration Spectrophotometric 0.7-2.8mequiv
L −1 Cl −

AS+3.09 log
C+9.4

0.9998 ±3.4
(7.04mequiv
L −1 )

2.8-27mequiv
L −1 Cl −

∆t=34.43
log C+109.3

0.9994 ±2.1
(7.04mequiv
L −1 )

∆S=2.53 log
C+7.4

0.9790 ±3.5
(7.04mequiv
L −1 )

a ∆t=peak width/s; ∆S=peak area covered by the base line and the measured height
b C=analyte concentration
Source: Reproduced with permission from the Royal Society of Chemistry [3]

Table 7.3 Determination of pH, alkalinity and total ionic concentration in natural and
potable water by the Canate and conventional methods

Alkalinity/ µg mL −1
CaCO 3

Sample Total ionic concentration/ mequiv

L −1

Conventional a Conventional a

pH FIA FIA Co

Bottled waters-
Font-bella 7.99 194.79 195.47 4.856 4.760

Cabras 8.58 481.11 453.21 12.373 12.444

Unbottled waters-
Córdoba (urban) 7.95 134.64 137.62 4.689 4.781