Multianion analysis, application of high performance and related chromatographic techniques - Determination of Anions in Natural and Treated Waters - page 712

Fig. 13.6 shows the chromatogram of a mixture of 10mg L −1 of chloride sulphate,
nitrate, phosphate and carbonate obtained with the flow colorimetric detector by elution
with 60% acetone water. As can be seen from Fig. 13.6 phosphate could be separated
from the strong acid anions and carbonate. The RS value between the strong acid anions
and phosphate was about 1.7. This RS value suffices for the quantitation of phosphate by
the peak area measurement with a computing integrator.
In Fig. 13.6 an unknown peak was observed between phosphate and carbonate. This
peak was due to water in the sample solution introduced into the chromatograph.
However, the peak did not interfere with the quantitation of phosphate.

13.3 Ion exchange chromatography

13.3.1 Non saline waters

13.3.1.1 Miscellaneous

Shintani and Dasgupta [18] have reported that post suppression membrane-based ion
exchange chromatography with fluorescence detection permits detection limits superior
to those obtained by conductivity detection in hydroxide eluent suppressed anion
chromatography.

13.3.2 Aqueous precipitation

13.3.2.1 Chloride and bromide

Akaiwa et al. [19] have used ion exchange chromatography on hydrous zirconium oxide
combined with a detection based on direct potentiometry with an ion selective electrode
for the simultaneous determination of chloride and bromide in non saline waters (Table
13.1).

Table 13.1 Accuracy tests

Sample Calibration curve method Standard addition method

Br − , µg L−1

Cl−, µg L−1

Br − , µg L−1 Cl − , µg L−1

Pond water (Gunma Univ) 27 8.6 27 9.0

Pond water (Kezouji Park) 31 19.3 35 18.5

Tap water (NittaTown) - 38.5 - 39.0

Tap water (Gunma Univ) - 9.5 - 9.0

Source: Reproduced with permission from Elsevier Science [19]