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A. N. Chebotarev, V. P. Dubovyiy D. V. Snigur
Sorption-spectrophotometric
determination of bismuth(III) in ores and concentrates
Abstract
The conditions
for the Bi(III) sorption from dilute aqueous solutions and its desorption from
the silica L100/250 surface are optimized using the mathematical experiment planning
by the Latin squares method. It was found that the sorption maximum degree
(95–98%) is reached at pH 4,5 near the zero charge point of the silica and the
Bi(OH)3 monomeric hydroxoforms dominate in the solution. The
sorption time does not exceed 30 min with a sorbent quantity of 0.4 g, and the
maximum desorption is observed when Bi(III) eluting by 0.5 M nitric acid
solution for 20 min. A sorption-spectroscopic technique for determination of
Bi(III) with xylenol orange was developed. The calibration curve is linear in
the concentration range 0.25–6.0 μg/ml, and the
LOD and LOQ are respectively 0.09 and 0.28 μg/ml.
The proposed method is tested on standard samples of tungsten ores and
molybdenum concentrate, and the sr value does not exceed
0,04.
Key words:
sorption, silica, spectrophotometry, bismuth (III), xylenol orange.
Copyright (C) Chemistry Dept., Moscow State University, 2002
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