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International Journal of Analytical and Bioanalytical Chemistry 2014; 4(1): 1-6
ISSN-2231-5012
Original Article
Liquid-liquid extraction of Rh(III) with new extractant N-decylpyridine-4-amine
from malonate media.
Mangal R Bagal, Mahadeo A Sakhare, Machindra K Lande, Balasaheb R Arbad*
Department of chemistry, Dr. B. A. M. University, Aurangabad (M.S), 431004, India
Phone: +910240 2403311; Fax: +91 0240 2403335:
E-mail:abrchem9@gmail.com
Received 18 November 2013; accepted 02 December 2013
Abstract
The liquid-liquid extraction of rhodium(III) from malonate media with (1×10
-4
) M N-decylpyridine-4-amine in xylene was
studied as a function of different parameters, such as the concentration of extractant, acid concentration, effect of different
diluents, effect of shaking period and effect of different diverse ions on extraction. The quantitative extraction of
rhodium(III) was observed in the pH range 7-10. The metal ion was stripped out from organic phase with 1M hydrochloric
acid and determined spectrophotometrically with SnCl
2
. As an application, the system was used for selective extraction of
rh(III) from its binary mixtures, synthetic mixtures and alloys. The molar absorptivity and Sandell’s sensitivi ty of
Rhodium(III)-N-decylpyridine-4-amine complex is (1.6×10
5
L mol
-1
cm
-1
) and (0.050 ug cm
-2
), respectively which
indicates the applicability of the method.
© 2013 Universal Research Publications. All rights reserved
Keywords: Solvent extraction, rhodium(III), N-decylpyridine-4-amine, synthetic mixtures.
1. Introduction
Rhodium is present at about 0.001 ppm in the earth crust
[1]. Precious metals comprised of the platinum group
metals, gold and silver, are in extensive use for catalytic
applications, electronics devices and as space materials.
There is significant source of rhodium which could be used
to increase supply. During the production of nuclear
energy, rhodium is generated as fission product and is
therefore present in the spent nuclear fuel[2]. Rhodium is
one of the most expensive rare metals and purification of
rhodium is almost difficult process because of its chemical
behavior in chloride media [3]. Therefore, the development
of a more efficient recovery process for rhodium is
essential. Rhodium has been introduced in to catalytic
converters, since then, approximately 73% of the world
production of rhodium is consumed in the production of
autocatalysts. The combination of increased industrial
demand for pure platinum group metals (PGM) along with
their scarcity has led to the need to maximize PGMs
recovery from spent sources [4]. Various analytical
techniques are available for the determination of rhodium
still most of them has some drawbacks, comparatively
solvent extraction technique is the most efficient method of
separation technology with high simplicity, speed and
applicability to both trace as well as macro amount of metal
ions.N-n-octylaniline was used for the quantitative
extraction of rhodium(III) from sodium malonate media
[5], extraction of rhodium was carried out from bromide
media in the presence of stannous chloride using cynex
471x and cynex 923 [6]. N,N’-diphenyltetra
decylmalonamide (DMDPHTDMA) extracts rhodium(III)
[7] and ruthenium(IV) using different concentrations of
Alanine 336 in kerosene using hydrochloric acid media [8].
The commonly used extractants for rhodium(III) are
EBIMTT [9], MBIMTT [10] N-n-octylaniline [11],
tributylphospate [12-15], bis-(2-ethylhexyl)phosphoric acid
(HDEHP) [16-18], N,N- dialkyl-N’- benzoylthiourea, N-
benzoyl - N,N’- dihexylthiourea [19], N’,N’- dihexyl and-
phenyl and N’-hexyl and-phenyl derivatives of N-benzoyl-
thiourea [20], N,N-dihexyl-N’-benzoylthiourea [21],
mercapto acetic acid and 2-mercaptobenzothiazole [22],
thiocynate [23], alkylaniline hydrochloride petroleum
sulphides [24,25], calyx(4) arenes[26], kelex-100 [27,28],
and 4-(non-5-yl) pyridine [29]. Though several
sophisticated techniques are in use for the determination of
trace and ultratrace quantities of rhodium, spectrometric
technique still has the advantage in respect to simplicity
and low operating costs but suffers due to matrix effects.
Hence, separation and preconcentration of trace level
quantities of rhodium is necessary prior to actual
quantitative analysis. Literature survey reveals that many
extractants are used for the separation of rhodium(III) but
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International Journal of Analytical and Bioanalytical Chemistry
Universal Research Publications. All rights reserved