Chemistry Reference
In-Depth Information
14.7
X-ray fluorescence spectroscopy
14.7.1
Aqueous precipitation
14.7.1.1
Chloride, bromide and iodide
Yamamoto [54] determined chloride, bromide and iodide in snow by X—ray
fluorescence spectrometry after precipitation of their silver salts using silver nitrate. The
colloidal silver halides formed were collected on a 0.45µm filter paper and dried at room
temperature. Limits of detection were 0.2µg for chloride, 0.1µg for bromide and 0.5µg for
iodide, and the relative standard deviation (n=5) was less than 5.0% for 10-80µg of the
chloride and bromide and was 8.2% for 10µg of the iodide. There were interferences in
the presence of ions which can exist in rainwater.
14.8
Anodic stripping voltammetry
14.8.1
Waste waters
14.8.1.1
Thiosulphate
Differential pulse anodic stripping voltammetry has been used [55] to detect thiosulphate,
a potential substrate for sulphuric acid forming thiobaccili. The method was selective for
thiosulphate in the presence of hydrogen sulphide, sulphite, polysulphide and elemental
sulphur. Reproducible results were obtained for thiosulphate concentrations of 5mg
L−1to 3mg L−1.
14.9
Cathodic stripping voltammetry
14.9.1
Non saline waters
14.9.1.1
Bromide and chloride
Bromide and chloride have been determined simultaneously in non saline waters [56] by
cathodic stripping voltammetry with a mercury-coated platinum wire as the working
electrode, a mercury/mercuric sulphate reference electrode, a platinum plate as the
auxiliary electrode, and perchloric acid as the supporting electrolyte. Bromide was
determined by using the peak at −0.1V and the sum of bromide and chloride was
determined by using the peak at 0.0V. The relative standard deviation of the method was
less than 10%, and the limit of detection for bromide was 0.4µg mL
−1
and for chloride
was 0.43µg mL−1
.
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