Multianion analysis, miscellaneous methods - Determination of Anions in Natural and Treated Waters - page 720

Table 14.1 gives data for the potentiometric determination of thiocyanate in the
presence and absence of cyanide. The cyanide added is without effect on the thiocyanate
determination when it is masked by formalin.

14.4 Flow injection analysis

14.4.1 Non saline waters

14.4.1.1 Thiosulphate, sulphate, sulphide, polysulphide and sulphite

Sonne and Dasgupta [26] carried out a simultaneous photometric flow injection analysis
of thiosulphate, sulphate, sulphide, polysulphide and sulphite.

14.4.1.2 Bromide, iodide and pseudohalides

Carlsson et al. [27] have described a flow injection spectrophotometric method for
determining bromide and iodide in river waters with a detection limit of 15M for
bromide.
Frenzel et al. [28] used flow injection analysis with electrochemical detection for
determining halide and pseudohalide ions in non saline water, with a relative standard
deviation of essentially 1.5%.

14.4.1.3 Silicate and phosphate

Linares et al. [29] discussed a flow injection analysis method for the simultaneous
determination of silicate and phosphate, based on the

Table 14.1 Potentiometric determination of thiocyanate in the presence and absence of
cyanide

An initial nitration volume of 1 35ml was used

Thiocyanate/mg Cyanide present/mg Absolute error/mg Recovery, %

Taken Found

25.18 25.46 - 0.28 101.1

25.18 25.50 10.0 0.32 101.3

12.50 12.65 - 0.15 101.2

12.50 12.66 10.0 0.16 101.3

9.47 9.52 - 0.05 100.5

9.47 9.58 20.0 0.11 101.2