Anions in non saline waters - Determination of Anions in Natural and Treated Waters - page 188

determination of chloride, fluoride, nitrate and ammonia in non saline waters
Source: Reproduced with permission from Springer Verlag [192]

Procedure
A general scheme of the whole flow-through system is given in Fig. 2.22. By changing
the position of the stopcock either standard solution or sample solution is introduced into
the system. In the case of many days of continuous analysis of river water, it was
indispensable to separate suspended matter on a glass frit. The standard solutions and
sample streams pass through coils thermostated at 25±0.5°C After passing the peristaltic
pump the sample or standard solution stream is divided into two

Table 2.19 Results of determinations in water with the flow through system in
comparison with reference methods (mg L −1 )

Fluoride Chloride

Sample Flow through

system

Potentiom with
TISAB

% Flow through

system

Titration with
Ag

%

1 0.178 0.174 +2.2 115.7 112.8 +2.6

2 0.166 0.166 0 108.6 109.0 −0.4

3 0.198 0.199 −0.5 119.2 118.6 +0.5

4 0.197 0.209 −5.9 119.8 119.5 +8.7

5 0.169 0.174 −2.9 66.1 72.4 −8.7

Source: Reproduced with permission from Springer Verlag GmbH [192]

parts. One of them flows directly to the mixing chamber preceding the ammonia sensor,
while the second one, after mixing with solution K (acetate buffer containing hydrogen
peroxide and DCTA) and debubbling approaches the measuring cell with chloride and
fluoride electrodes and a common reference electrode. Leaving this cell, the stream is
mixed with solution II (phosphoric acid) and, after debubbling, enters the nitrate
electrode cell. The automatic electrode switch allows the potential values of all electrodes
to be printed with the frequency controlled by the printer using the Orion 751 printer. The
frequency of changes is in the range 6s—1h.
Chloride and fluoride determinations obtained in non saline water by this procedure are
compared with those obtained by conventional methods in Table 2.19. Generally, results
agreed within ±5% with those obtained by the reference method.

2.58.2 High performance liquid chromatography
Salov et al. [115] determined chloride, bromide, iodide, chlorate, bromate and iodate in
non saline waters by high performance liquid chromatography with inductively coupled
oxygen plasma mass spectrometry as a detector.