Multianion analysis, miscellaneous methods - Determination of Anions in Natural and Treated Waters - page 733

paper mill waste waters [60] using a sulphide ion selective electrode. The electrode is
used as an indicator electrode in potentiometric titration with mercuric chloride. In 0.1N
sodium hydroxide medium, sulphide and polysulphides are titrated to form mercuric
sulphide (and HgSx). Mercuric ions, thiosulphate and sulphite can also be converted into
thiosulphate and can be titrated; sulphite can be decomposed with formaldehyde and so
thiosulphate can be titrated alone.
14.12 Miscellaneous anions
14.12.1 Non saline waters
Keundler and Reich [61] have characterised electrolyte systems for the isotachophoresis
of anions by cluster analysis. The leading electrolyte system with a pH of 3 and one with
a pH between 6 and 10 were found, based on hierarchical and a non-hierarchical
clustering procedure, to be the most favourable binary combination for anion
identification purposes. Ternary combinations were also selected. Other systems studied
do not increase the identification power.
Jackson and Haddad [41] have discussed the optimisation of injection techniques in the
isotachoelectrophoresis of trace anions in non saline waters in amounts down to low ppb.
Hutta et al. [62] studied use of various solid phase adsorbents in the
isotachoelectrophoresis of anions in non saline waters.
Preswell et al. [63] used capillary electrophoresis to determined sub ppm levels of
anions in non saline waters.
Romano and Krol [64] demonstrated the separation of anions using capillary
electrophoresis and showed that results obtained agreed well with those obtained by ion
chromatography.
14.12.2 Aqueous precipitation
14.12.2.1 Chloride, fluoride, bromide, nitrate and sulphate
Slanina et al. [65] have discussed various methods for the determination of anions in
rainwater. Methods discussed include ion selective electrodes (chloride, fluoride),
neutron activation analysis (chloride, bromide), ultraviolet spectroscopy (nitrate [66]) and
nephelometry (sulphate [67]).
14.12.2.2 Miscellaneous
Cox et al. [68] discuss the ion exchange treatment of complicated rain water samples
prior to ion chromatographic analysis. Such treatment is often preferable to sample
dilution as a means of reducing electrolyte concentration.
Cheam and Chau [69] have discussed the automated simultaneous analysis of anions
and mono and divalent cations in rain water.