CHAPTER-3 SOLVENT EXTRACTION STUDIES OF RUTHENIUM(III...
Transcript of CHAPTER-3 SOLVENT EXTRACTION STUDIES OF RUTHENIUM(III...
Chapter 3 – Solvent extraction studies of ruthenium(III) using high molecular weight amine
Analytical Chemistry Laboratory, Dept. of Chemistry, Shivaji University, Kolhapur 26
CHAPTER-3
SOLVENT EXTRACTION STUDIES OF RUTHENIUM(III) USING
HIGH MOLECULAR WEIGHT AMINE
3.1 Introduction
Ruthenium is a scarce element that is found in about 10-8 % of the
earth’s crust. It is present in much larger amounts in chondrite and, especially,
in iron meteorites ((1-6) x 10-4 %). It usually occurs in association with other
platinum group metals [1].
Ruthenium is a rare and polyvalent hard white transition metal. Small
amount of Ru can increase the hardness of platinum and palladium. The
corrosion resistance of titanium is increased markedly by the addition of a
small amount of ruthenium [2]. Ruthenium is a versatile catalyst. This is used
to remove H2S from oil refineries [3]. Ruthenium was also suggested as a
possible material for microelectronics because its use is compatible with
semiconductor processing techniques [4]. Due to its hardness and corrosion
resistance, ruthenium is used to coat electrodes in the chloralkali process which
produces chlorine and caustic soda for a wide range of industrial and domestic
applications. In the future, the use of ruthenium in alloys for aircraft turbine
blades will help to reduce the CO2 impact of air travel on the environment. If
current prototypes are successful, their high melting points and high
temperature stability will allow for higher temperatures and, therefore, a more
efficient burning of aircraft fuel [5]. Recently, platinum metals, especially
ruthenium and its chlorocomplexes, have been much used in the catalytic
oxidation of some organic compounds. Organometallic ruthenium carbene and
allenylidene complexes are efficient catalysts for olefin metathesis [6].
Ruthenium complex shows greater resistance to hydrolysis and has more
selective action on tumors. Ruthenium and its alloys also have a widespread
application in jewellery [1]. In radiochemistry, the interest lies in the separation
of rhodium from ruthenium since rhodium is daughter of ruthenium by beta
decay [7].
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Analytical Chemistry Laboratory, Dept. of Chemistry, Shivaji University, Kolhapur 27
The growing use of ruthenium in widely different fields has made it
necessary to develop simple, inexpensive and sensitive method for its
separation and determination. To recover and separate metals from low-value
resources, such as low-grade ores and recycled materials, the solvent extraction
process is the best option [8].
3.2 Review of literature for liquid-liquid extractive separation of
ruthenium(III)
In recent years various reagents have been studied for liquid-liquid
extraction of ruthenium(III). The reageats such as 2-mercaptobenzimidazole
used as extractant for ruthenium(III) in n-butanol [9], 3-hydroxy-2-methyl-1-
phenyl-4-pyridone [10], Cyanex 921[11], and Cyanex 923, Cyanex 471,
Cyanex 272, LIX 54, LIX860N-I [12] are reported for solvent extraction.
Also, some organophosphorus compounds like triphenylphosphine
(TPP) extracts chlorocomplex of ruthenium(III) in 1,2-dichloroethene only in
presence of SnCl2 [13]. Method requires heating before extraction and
prolonged equilibrium time (60 min) for quantitative recovery of ruthenium.
Bis (2-ethylhexyl) phosphoric acid [14, 15] and tributyl phosphate [16-19]
extract nitrosyl-ruthenium complex in dodecane or kerosene or solvesso-100
[18, 19]. This method was used for extraction of U, Zr and Ru from nuclear
fuel reprocessing but needs longer time, about 6 months for the formation of
extractable ruthenium complex. Octyl (phenyl)-N-N-di-isobutyl
carbamylmethylphosphine oxide was used as extractant for actinides and
fission products in dodecans from nitric acid media [20]. However, extraction
of ruthenium was not quantitative and equilibrium time was more (1 hr.).
Solvent extraction by high molecular weight amine (HMWA) has
become increasingly popular in recent years for studying metal complexes.
These are known as liquid anion exchangers which uniquely combine some of
the advantages of liquid-liquid extraction and ion exchange. It was further
observed that the acid binding properties of HMWA depend on the fact that
acid salts of these bases are essentially insoluble in water while they are readily
Chapter 3 – Solvent extraction studies of ruthenium(III) using high molecular weight amine
Analytical Chemistry Laboratory, Dept. of Chemistry, Shivaji University, Kolhapur 28
soluble in hydrocarbon solvents [21]. High molecular weight amine (HMWA)
reported for ruthenium(III) extraction are Alamine 336 [22], Alamine 300,
Aliquat 336 [12], tri-iso-octylamine [23], trioctylamine oxide [24], The
thiocyanate complex of ruthenium(III) was extracted with bis (2-
ethylhexyl)amine in 1,2-dichloroethene, this method was used for
determination of ruthenium in substrates for microelectronics applications but
optimal pH range was narrow [25]. A synergistic extraction of chlorocomplex
of ruthenium(IV) with trioctylamine [26] in mixed solvents like
tributylphosphate thenoyltrifluoroacetone and 1-phenyl-3-methyl-4-benzoyl-
pyrazolidone was reported. N-Octylamine [27] was reported for the extraction
of ruthenium(IV) from hydrochloric acid media. The solvent extraction of
ruthenium from hydrochloric acid media has been carried out using N,N’-
Dimethyl-NN’-dicyclohexylmalonamide (DMDCHMA) dissolved in 1,2-
dichloroethane [28]. Trinonylamine [29] extracts ruthenium(IV) in kerosene
from hydrochloric acid madia. In this method synergistic effect on ruthenium
extraction was observed in presence of dimonolyamine (DNA), aliquat and
methyl iso butyl ketone (MIBK). Alkylaniline [30] extracts chlorocomplex of
ruthenium in toluene and method was applied for the extraction of noble
metals. A primary amine i.e. dodecylamine [31] was reported for the
extraction of ruthenium(III) in mixed solvents from hydrochloric acid media
but the extraction efficiency was independent on the concentration of extractant
and method was time consuming. Octylaniline hydrochloride [32] and
alkylaniline hydrochloride [33, 34] extracts ruthenium from chloride or sulfate
medium in toluene. p-Octylaniline [35,36] in presence of bis(2-ethyl-hexyl)
dithiophosphate extract ruthenium in hydrochloric acid media. The method was
found to be applicable for extraction of ruthenium from copper- nickel ore and
also for extraction of noble metals [33-35]. Ruthenium(III) was extracted by
tetra-nitroaniline [37] in nitric acid media. The extracted ruthenium(III) was
backstripped with 10 % NaOH and method was selective in presence of large
amount of iridium. But, method needs heating before extraction and also
multiple extraction for recovery of ruthenium. Trialkylamine [38] extracts
Chapter 3 – Solvent extraction studies of ruthenium(III) using high molecular weight amine
Analytical Chemistry Laboratory, Dept. of Chemistry, Shivaji University, Kolhapur 29
ruthenium(III) in kerosene from nitric acid media. The method can be used for
selective separation of ruthenium(III) from uranium.
The oxygenated and hydrocarbon solvents like chloroform [39], carbon
tetrachloride [40], MIBK [41], paraffin oil [42], mixtuer of isoamyl alcohol and
isobutyl methyl metone [43] have also been used as extractants for ruthenium.
Ruthenium was extracted in chloroform from hydrochloric acid and method
was suitable for determination of ruthenium in iron meteorites. However,
method is selective in presence of NaIO4 [39]. Carbon tetrachloride extracts
ruthenium in sulphuric acid media and method was applicable for the
separation of ruthenium from osmium but extraction is highly selective only in
presence of oxidizing agents [40]. MIBK used as extractant for ruthenium(III)
in presence of hydrochloric acid media. The extraction of metals from
thiocyanate media has been successful in applied chemistry. Ruthenium(III) is
separated by purex process using paraffin oil in nitric acid medium but it is
necessary to oxidise Ru to RuO4 by addition of ceric nitrate before extraction
[42]. Mixture of isoamyl alcohol and MIBK in 1:1 ratio extract ruthenium in
large excess of platinum but iridium interferes in the extraction procedure [43].
During last few years substituted thioureas have been reported for the
solvent extraction of ruthenium. N,N-dialkyl-N’-benzoyl-thioureas [44] extract
ruthenium(III) in Solvesso 150. Method was applicable for extraction and
separation of platinum group metals from solution containing base metals. But
optimal pH range is narrow. N-mono- and N,N-di-substituted benzoylthioureas
[45] extract ruthenium(III) from chloride media in toluene but the method
demands large volume of the extracting solvent to affect the quantitative
recovery of metal. Attempts have also been made to selectively separate
ruthenium(III) from associated elements with P-50 oxime [46], di(2-
ethylhexyl) sulfoxide [DHSO] [47]. The various investigated systems are
presented in tabular form in Table 3.1 to review the literature in terms of
various extractants used and special characteristics regarding those systems.
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Analytical Chemistry Laboratory, Dept. of Chemistry, Shivaji University, Kolhapur 30
Development of new extraction system for extraction of ruthenium(III)
especially in weak organic acid solutions is a topic of great interest. The goal of
this work is to study the extraction properties of n-octylaniline with respect to
noble metal such as ruthenium(III) from weak organic acid media. In this work,
n-octylaniline-malonate system was studied to investigate the extraction of
aqueous ruthenium(III) solution as a function of various parameters. The
proposed method is used for rapid and selective separation of ruthenium(III)
form associated elements in their binary mixtures. It is also tested for
separation and determination of ruthenium(III) from various real samples like
catalysts and synthetic mixture sample.
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Table 3.1 Summary of methods for solvent extraction of ruthenium(III)
System Aqueous
phase Organic
phase Special features
Ref.No.
2-mercaptobenzimidazole
pH-2.0 n-Butanol Rapid method for quantitative extraction of ruthenium(III).
9
3-hydroxy-2-methyl-1-phenyl-4-pyridone
pH-6.5 to 7.0
Dichlorome- thane
Heating of the aqueous phase before extraction.
Separation of ruthenium from large amount of palladium(II) and rhodium(III).
10
Cyanex 921 HCl
Toluene Ruthenium extraction study in presence or absence of tin(II) chloride.
Ruthenium separates from Os, Ir.
11
Cyanex 923, Cyanex 471, Cyanex 272, LIX 54, LIX860N-I, Alamine 300, Aliquat 336
HCl - Separation of ruthenium from iridium, rhodium.
12
Ttriphenylphosphine (TPP)
HCl 1-6 M + SnCl2
1,2-Dichloro- ethane
Shaking for 60 min and heating before extraction.
Method applicable for extraction of platinum group metals.
13
Bis (2-ethylhexyl) phosphoric acid
HCl, pH 4.05
Isopar M Method applicable for extraction of rhodium and iridium.
14, 15
HCl, 0.5 M; thiourea pH 4.5.
Isopar M
Ruthenium was backstripped with 1M HCl
Ruthenium recovery 40.8 %
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Analytical Chemistry Laboratory, Dept. of Chemistry, Shivaji University, Kolhapur 32
Tributyl phosphate (TBP)
HNO3, 2 M
Solvesso-100
Extraction of ruthenium in presence of gamma irradiated sulphoxides
Method applied for extraction of U, Zr, and Ru.
16
HNO3, 3 M
Dodecane The acid solution was aged in a dark box for 6 months in order to equilibrate reaction between ruthenium complex.
Ruthenium was backstripped with 0.5 M Na2SO3 Solution.
17
HNO3
n-Dodecane, Kerosene
Ruthenium extracting as nitrosyl-ruthenium.
18, 19
Octyl (phenyl)-N-N-di-isobutyl carbamylmethyl- phosphine oxide (CMPO)
HNO3 Dodecane Extraction of ruthenium in presence of TBP.
Method applicable for Pm(III), U(VI), Pu(IV), Am(III), Zr(IV), Ru(III), Fe(III), Pd(II).
The nature of the species has been suggested.
20
Alamine 336 HCl Kerosene Extraction of ruthenium (III) increased with increasing concentration of HCl up to 5 M
Method applicable for separation of Ir(III), Rh(III), Ru(III) with the help of strripant.
22
Tri-iso-octylamine HCl, 4 M Carbontetra- chloride
SCN-, CN-, S2-, S2O32-,
EDTA, bromide, sulphite nitrite, iodide, Ag+ interfere in extraction.
Salting out agents used in separation of other metals
23
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Trioctylamine oxide HCl CCl4 Ruthenium chloro complexes
occurs during extraction
24
Bis (2-ethylhexyl)amine
HCl 0.3 M; NaSCN, 0.15- 0.7 M, pH, 2
1,2-Dichloro- ethene
Method used for the determination of ruthenium in substrates for microelectronics applications.
25
Trioctylamine HCl, 4 M Mixed solvents system
Synergistic extraction of Ru(IV) with solvents like TBP, thenoyltrifluoroacetone and 1-phenyl-3-methyl-4-benzoyl-pyrazolidone-5
26
N-octylamine 1 M HCl Xylene Method required large amount of extractant.
27
N,N’-Dimethyl-NN’-dicyclohexylmalonami-de (DMDCHMA)
HCl 1,2-Dichloro- ethene
Method applicable for extraction of PGMs
28
Tri-nonyl-amine (TNA) HCl > 3 M
Kerosene Synergistic extraction of Ru(IV) in presence of TNA and MIBK.
29
Alkylaniline HCl 2-3 M
Toluene Method applicable for extraction of precious metals
30
Dodecylamine HCl > 6 M
CCl4 : isoamyl alcohol (9:1)
Recovery of Ruthenium(III) 80 %
Shaking time 20 min
31
Octylaniline hydrochloride
H2SO4 Toluene Extraction of ruthenium(III) in presence of 20 % NaCl
32
Alkylaniline hydrochloride
HCl Toluene Method was used for extraction of PGMs except osmium and determination by AAS.
Extraction in presence of petroleum sulphides.
33
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HCl, 6 M Toluene Extraction in presence of
petroleum sulphide. Method was used for
extraction of PGMs, gold in copper-nickel ore and related plant materials
34
p-octylaniline
HCl 2-4 M
Toluene Extraction of ruthenium in presence of bis(2-ethyl-hexyl) dithio- phosphate.
Method applied for extraction of Ru from Copper-Nickel sulphide ore.
35, 36
Tetra-nitroaniline HNO3,
1 % Tetra- nitroaniline
Ruthenium(III) was backstripped with 10 % NaOH.
Ruthenium was separated from solution containing large amount of iridium.
37
Trialkylamine HNO3 Kerosene The method can be used for selective separation from uranium.
38
Chloroform HCl, NaIO4
Chloroform Method was suitable for determination of ruthenium in iron meteorites.
39
Carbon tetrachloride H2SO4, 6 M
CCl4 Ruthenium was separated from osmium
40
MIBK HCl, 2-3 M; KSCN
MIBK Method applicable for extraction for PGMs.
Ruthenium recovery Ru > 95 %
41
Paraffin oil HNO3 Paraffin oil Ruthenium(III) selectively separated from purex process
42
Isoamyl alcohol: MIBK
HCl, 6 M Isoamyl alcohol: MIBK
Method applicable for extraction of Ru, Ir, and Rh in large excess of platinum.
43
Chapter 3 – Solvent extraction studies of ruthenium(III) using high molecular weight amine
Analytical Chemistry Laboratory, Dept. of Chemistry, Shivaji University, Kolhapur 35
N,N-dialkyl-N’-benzoyl-thioureas
pH, 3 Solvesso 150
Coextraction Cu and Fe, re-extraction with 4 M H2SO4.
Method applied for separation of PGMs from Cu, Fe, Ni, Co and Zn.
44
N,N-di-substituted benzoylthioureas
HCl, 0.1- 6 M
Toluene Method used for the solvent extraction of platinum metals.
Efficiency of extraction increases as concentration of ligand increases.
45
P-50 oxime HNO3
4 M Escaid 100 Method applicable for
extraction of palladium. 46
Di(2-ethylhexyl) sulfoxide [DHSO]
HNO3
Kerosene The extraction abilities
for U,Th and some fission products are presented
47
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Analytical Chemistry Laboratory, Dept. of Chemistry, Shivaji University, Kolhapur 36
3.3 Experimental
3.3.1 Apparatus
Elico digital spectrophotometer model l2 Chemito 215D with 1 cm
quartz cells was used for absorbance measurements and pH measurements were
carried out using an Elico digital pH-meter model LI-127. All weighing
operations were done by using Tapson’s analytical single pan balance model
200 T having 0.001 gm accuracy.
3.3.2 Reagents
Standard ruthenium(III) solution
A stock solution of ruthenium(III) was prepared by dissolving 1 g of
ruthenium chloride hydrate (Johnson Matthey, UK) in dilute analar HCl (1 mol
dm-3) and diluting to 250 mL with water and standardized [48]. A working
solution of 200 µg/mL was made by diluting the stock solution with water.
4’-ChloroPTPT
1-(4’-Chlorophenyl)-4,4,6-trimethyl-(1H,4H)-pyrimidine-2-thiol
(4’-ChloroPTPT) was prepared by the method of Mathes [49-52] and used for
the specrophotometric determination of ruthenium(III).
Standard solution of diverse ions were prepared by dissolving AR grade
reagents in water or dil HCl. All the organic solvents were used after double
distillation. All chemicals used were of AR grade.
n-Octylaniline
The reagent n-octylaniline was prepared by the method of Pohlandt’s
[53] and its 0.1 M solution was prepared in xylene. Aqueous solutions were
prepared with water. Double distilled water was used through the experimental
study.
3.3.3 General procedure for extraction and determination of
ruthenium(III)
To an aliquot containing 200 µg ruthenium(III) in 25 mL volumetric
flask a sodium malonate was added to get the concentration of solution 0.05 M.
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The pH of the resulting solution was adjusted to 3.5 with dilute HCl and NaOH
solution. The aqueous solution was shaken with 10 mL 0.1 M n-octylaniline in
xylene for 5 min. After the phase separation, the organic phase was stripped
with the 4:1 combination of 2 % of NaCl and 1 M HCl.
The back extracts were evaporated to moist dryness and dissolved in
minimum amount of aqua regia and evaporated with two 2 mL portions of
concentrated HCl to remove oxides of nitrogen. The residue was dissolved in
0.1 M and ruthenium(III) was determined spectrophotometrically by
4’-chloroPTPT at λ max = 605 nm [54]. All the experiments were repeated on
an average five times.
The percentage extraction, % E, was calculated using expression
% E = (metal extracted/ metal taken) ×100 …..(3.1)
and the distribution ratio, D, was calculated using expression
D = (% E / (100 – % E)).Volume aqueous phase/Volume organic phase) (3.2)
3.4 Results and discussion
3.4.1 Effect of pH
The effect of pH on the percentage extraction of ruthenium(III) was
studied in the pH range of 0.5 to 10 with 0.1 M n-octylaniline in xylene
(Table 3.2). The Fig. 3.1, shows that the extraction of ruthenium(III) was found
to be quantitative in the pH range 3.1 to 4.0. Hence, all extractions of
ruthenium(III) were carried at pH 3.5.
3.4.2 Effect of reagent concentration
Extraction of ruthenium(III) was carried out with various concentrations
of n-octylaniline in xylene (Table 3.3). To optimize the extraction condition,
other parameters like pH, period of equilibration and diluent were kept
constant. The extraction was found to be increased with increasing reagent
concentration. The extraction of ruthenium(III) was quantitative in the range
0.09 M to 0.13 M of n-octylaniline in xylene (Fig 3.2). However, 10 mL of
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Analytical Chemistry Laboratory, Dept. of Chemistry, Shivaji University, Kolhapur 38
0.1 M n-octylaniline in xylene was recommended for general extraction
procedure.
3.4.3 Effect of weak organic acid concentration
The extraction of ruthenium(III) was carried out at pH 3.5 with 0.1 M
n-octylaniline in xylene in the presence of varying concentrations of sodium
malonate, sodium succinate, and sodium salicylate as weak acid media
(Table 3.4). The extraction of 200 μg ruthenium(III) was found to be
quantitative in the range of 0.04 M - 0.055 M for sodium malonate and further
increase in malonate concentration there was decrease in extraction. The
extraction of ruthenium(III) was found to be incomplete in the salicylate and
succinate media. Thus, 0.05 M concentration of malonate was used throughout
the experimental work (Fig 3.3).
3.4.4 Effect of diluents
In this study, extraction of ruthenium(III) was carried out by using various
aromatic and aliphatic organic diluents. It was found that the extraction of
ruthenium(III) was quantitative with xylene, toluene and in benzene while there
was incomplete extraction in methyl isobutyl ketone (93.04 %), n-butyl
alcohol (42.2 %) and no extraction in amyl alcohol, chloroform,
1,2-dichloroethane, carbon tetrachloride and amyl acetate. Throughout the
experiment xylene was used as solvent (Table 3.5).
3.4.5 Effect of stripping agents
Ruthenium(III) from organic phase was stripped with three 10 mL
portions of various stripping agents (Table 3.6). Ruthenium(III) was
quantitatively stripped with 30 mL 2 % NaCl and 10 mL 1 M HCl. However,
percentage recovery of ruthenium(III) from organic phase was found to be
incomplete with strippants like acetate buffer, sodium hydroxide, ammonia and
potassium hydroxide. In recommended procedure, 30 mL 2 % NaCl and
10 mL 1 M HCl was used for the complete stripping of loaded organic phase.
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3.4.6 Equilibration time
The period of equilibration was varied from 1 to 18 min (Table 3.7). The
extraction of ruthenium(III) was quantitative over a period of 3 min shaking of
the solution, but with prolonged shaking over 12 min (Fig. 3.4) there was
decrease in the percentage extraction of ruthenium(III) due to the dissociation
of ion-pair complex. Thus, equilibration time for 200 μg ruthenium(III)
extraction was kept about 5 min throughout the study.
3.4.7 Extraction behavior of ruthenium(III) as a function of metal loading
capacity
Varying concentrations of ruthenium(III) (50 – 2000 μg) were extracted
with 10 mL portions of 0.1 M n-octylaniline in xylene from 0.05 M sodium
malonate media. It was observed that extraction of ruthenium(III) was
quantitative upto 500 μg (Table 3.8).
3.4.8 Effect of aqueous to organic volume ratio
The effect of contacting the different volume ratios of aqueous to
organic phase was studied (Table 3.9). The results indicate that the preferred
aqueous/organic (A/O) phase ratio in this study must be in between 1:1 to 4:1.
Extraction decreases after ratio of 4:1 due to the less availability of reagent.
However, in the recommended procedure, the phase ratio was maintained at
2.5:1.
3.4.9 Stoichiometry of extracted species
Attempts were made to ascertain the nature of the extracted complex
species using log D - log C plots. The graphs of log D[Ru(III)] against
log C[n-octylaniline] at fixed sodium malonate concentration (0.05 M ) were found
to be linear and having slopes of 1.0 and 0.99 value at pH 5.0 and 6.0,
respectively (Fig. 3.5). Also plot log D[Ru(III)] against logC[Malonate] at fixed
n-octylaniline concentration (0.1 M) were linear and slope values were found to
be 2.0 and 1.75 at pH 5.0 and 6.0, respectively (Fig. 3.6). The probable
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Analytical Chemistry Laboratory, Dept. of Chemistry, Shivaji University, Kolhapur 40
composition of extracted species is calculated to be 1:2:1 (Metal: Acid:
Extractant). The possible mechanism of extracted species appears to be
protonated n-octylaniline which forms cationic species as
[CH3(CH2)7C6H4NH3] +(org) while malonate (bidentate ligand) combines with
ruthenium(III) to form anionic species as Ru(C3H2O4)-2(aq) and both of them
associate to form ion-pair of the type [CH3(CH2)7C6H4NH3+ Ru(C3H2O4)-
2](org)
and being neutral constitutes extractable species.
The possible mechanism of ion- pair complex is as follow:- CH3(CH2)7C6H4NH2(org) + H+ CH3(CH2)7C6H4NH3
+(org) (3.3)
Ru3+(aq)
+ 2C3H2O4-(aq) Ru(C3H2O4)2
-(aq) (3.4)
CH3(CH2)7C6H4NH3+
(org) + Ru(C3H2O4)2-(aq) [CH3(CH2)7C6H4NH3
+Ru(C3H2O4)2-](org) (3.5)
3.4.10 Effect of diverse ions The effect of a large number of foreign ions on the extraction of
200 µg/mL of ruthenium(III) with n-octylaniline was investigated following the recommended procedure. The tolerance limit of individual foreign ions was set so that error in percentage recovery was not more than ±2 %. Rh(III) and Pd(II) were masked with 25 mg tartrate and Ir(III) with 25 mg oxalate. Au(III) was masked with 10 mg bromide (Table 3.10). The species showing interference in the procedure were ascorbate, thiourea, citrate and thiocyanate.
3.5 Applications 3.5.1 Separation of ruthenium(III) from associated metal ions
The method permits separation and determination of ruthenium(III) from binary mixtures containing Os(VIII), Pt(IV), Cu(II), Fe(III), Co(II), Ni(II), Se(IV) and Te(IV). Ruthenium(III) was separated from these associated metal ions, under the optimum extraction conditions of ruthenium(III) where, all the added metal ions were remained quantitatively in aqueous phase from which they were determined spectrophotometrically by standard methods [55-60]. Ruthenium(III) from organic phase was stripped and estimated spectrophotometrically by 4’-chloroPTPT method (Table 3.11).
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Under the optimum extraction condition of ruthenium(III), some metals like Rh(III), Pd(II), Ir(III) and Au(III) were co-extracted. Rh(III) and Pd(II) were masked with 25 mg tartrate. Ir(III) and Au(III) were masked with 25 mg oxalate and 10 mg bromide respectively. The masked metal ions remained in the aqueous phase, they were demasked with perchloric acid followed by hydrochloric acid. The residue was dissolved in 10 mL water and evaporated to moist dryness to remove trace of acid completely. The residue containing Rh(III), Pd(II), Ir(III) and Au(III) were determined spectrophotometrically by standard methods [54-59].
3.5.2. Separation of ruthenium(III) from Ternary mixture The selectivity of extraction was also achieved by the use of a suitable masking agent for added metal ion. When a ternary mixture containing ruthenium(III), palladium(II) and rhodium(III) was extracted from 0.05 M malonate acid with 10 mL of 0.1 M n-octylaniline in xylene at pH 3.5 by masking Pd(II) and Rh(III) with tartrate (25 mg), it was found that ruthenium(III) was extracted; whereas palladium(II) and rhodium(III) remained unextracted. Ruthenium(III) was strripped with 2 % of NaCl and 1 M HCl (4:1) and estimated as per the recommended procedure [54].
The aqueous phase containing tartrates of palladium(II) and rhodium(III) and excess of malonate were decomposed by the addition of concentrated hydrochloric acid. Then, the solution was adjusted to 0.03 M with sodium malonate. Rhodium(III) was extracted quantitatively with 10 mL of 0.1 M n-octylaniline in xylene at pH 9.0. Rhodium(III) from organic phase was stripped with 1 M hydrochloric acid (2×10 mL) and estimated spectrophotometrically with stannous chloride–potassium iodide method [55]. The aqueous phase containing malonate was decomposed with concentrated hydrochloric acid and residue extracted into 0.1 M hydrochloric acid. The solution was made to 0.085 M with respect to sodium salicylate. Palladium(II) was extracted with 10 mL of 0.07 M n-octylaniline in xylene at pH 1.5. Palladium(II) from organic phase was stripped with 5 M ammonia (2×10 mL) and estimated spectrophotometrically with 4’-chloroPTPT [54] (Table 3.12).
Chapter 3 – Solvent extraction studies of ruthenium(III) using high molecular weight amine
Analytical Chemistry Laboratory, Dept. of Chemistry, Shivaji University, Kolhapur 42
3.5.3 Determination of ruthenium(III) from synthetic mixture corresponding to alloys
The proposed method was applied to the extraction and determination of ruthenium(III) from malonate media at pH 3.5 in various ternary mixtures (Table 3.13). Ruthenium(III) was extracted with 0.1 M n- octylaniline in xylene while Pt(IV), Ni(II), Te(IV), Fe(III), Co(II), U(VI) remained unextracted in the aqueous phase. However, Rh(III) and Pd(II) were masked by 25 mg tartrate and Ir(III), Au(III) with 25 mg oxalate and 10 mg bromide respectively. The extracted ruthenium(III) was stripped and determined by 4’-chloroPTPT method spectrophotometrically. 3.5.4 Analysis of ruthenium(III) in catalysts sample Ruthenium(III) activated carbon and alumina (0.1 g) was dissolved in 20 mL aqua regia. The solution was evaporated to moist dryness. Two 5 mL portions of hydrochloric acid were added and evaporated till all the nitric acid was removed. The residue was extracted in 1 M hydrochloric acid. The solution was filtered and the filtrate was diluted to 100 mL. An aliquot of this diluted solution was analyzed for ruthenium(III) content by the proposed method. It was found that there is a good agreement with the certified value (Table 3.14). 3.6 CONCLUSIONS
The extraction equilibria of ruthenium(III) and sodium malonate have been investigated systematically using n-octylaniline in xylene.
The results also demonstrates that n-octylaniline has good extractability for ruthenium(III) in malonate media at pH 3.5 compared with some other high molecular weight amines and organophosphorus compounds. Further, n-octylaniline has good regeneration and loading capacities.
The extraction behavior of ruthenium(III) in presence of other associated elements have been investigated. The method is applied for binary separation of ruthenium(III) from associated transition metals and other rare earths.
Chapter 3 – Solvent extraction studies of ruthenium(III) using high molecular weight amine
Analytical Chemistry Laboratory, Dept. of Chemistry, Shivaji University, Kolhapur 43
Table 3.2 Extraction of ruthenium(III) as a function of pH Ruthenium(III) = 200 µg Sodium malonate = 0.05 M Aq: org ratio = 2.5: 1 Extractant = 0.1 M n-octylaniline in xylene Strippant = 2 % NaCl +
1 M HCl (4:1)
pH Percentage extraction, (% E) Distribution ratio, (D)
0.5 41.2 1.75
1.0 42.0 1.81
2.0 44.3 1.98
3.0 97.6 101.6
3.1 99.9 2497.5
3.3 99.9 2497.5
3.5* 99.9 2497.5
3.7 99.9 2497.5
3.9 99.9 2497.5
4.0 99.9 2497.5
5.0 83.5 12.65
6.0 70.8 6.06
7.0 27.8 0.96
8.0 26.8 0.91
9.0 25.7 0.86
10.0 22.9 0.74
* Recommended for general extraction procedure
Chapter 3 – Solvent extraction studies of ruthenium(III) using high molecular weight amine
Analytical Chemistry Laboratory, Dept. of Chemistry, Shivaji University, Kolhapur 44
Table 3.3 Extraction behavior of ruthenium(III) as a function of n-octylaniline concentration
Ruthenium(III) = 200 µg pH = 3.5 Aq: org ratio = 2.5: 1 Sodium malonate = 0.05 M Strippant = 2 % NaCl + 1 M HCl (4:1)
n-Octylaniline, (M) Percentage extraction,(% E)
Distribution ratio, (D)
0.01
20.8 0.65
0.02
21.9 0.70
0.03
26.5 0.90
0.04
36.0 1.40
0.05
46.9
2.20
0.06
54.6 3.00
0.07
61.3 3.95
0.08
91.7 27.62
0.09
99.9 2497.5
0.10*
99.9 2497.5
0.11
99.9 2497.5
0.12
99.9 2497.5
0.13
99.9 2497.5
* Recommended for general extraction procedure
Chapter 3 – Solvent extraction studies of ruthenium(III) using high molecular weight amine
Analytical Chemistry Laboratory, Dept. of Chemistry, Shivaji University, Kolhapur 45
Table 3.4 Extraction behavior of ruthenium(III) as a function of weak
organic acid concentration Ruthenium(III) = 200 µg pH = 3.5 Aq: org ratio = 2.5: 1 Extractant = 0.1 M n-octylaniline in xylene Strippant = 2 % NaCl +
1 M HCl (4:1)
Acid concentration,
(M)
Sodium malonate Sodium succinate Sodium salicylate
% E D % E D % E D 0.01 48.7 2.37 27.0 0.92 10.0 0.27
0.02 54.1 2.94 45.0 2.04 15.0 0.44
0.03 75.1 7.54 53.7 2.89 24.3 0.80
0.04 99.9 2497.5 60.0 3.75 45.0 2.04
0.045 99.9
2497.5 64.0 4.44 61.0 3.91
0.05* 99.9 2497.5
69.0
5.56
78.0
8.86
0.055 99.9
2497.5 74.0 7.11 84.0 13.12
0.06 96.3 65.06 70.0 5.83 80.0 10.00
0.07 59.7 3.70 62.0 4.07 76.0 7.91
0.08 50.2 2.52 58.3 3.49 72.3 6.52
0.09 30.1
1.07 50.0 2.50 70.0 5.83
0.1 26.2
0.88 48.3 2.33 65.0 4.64
* Recommended for general extraction procedure, D = Distribution Ratio % E = Percentage extraction
Chapter 3 – Solvent extraction studies of ruthenium(III) using high molecular weight amine
Analytical Chemistry Laboratory, Dept. of Chemistry, Shivaji University, Kolhapur 46
Table 3.5 Extraction of ruthenium(III) with various diluents Ruthenium(III) = 200 µg pH = 3.5 Aq: org ratio = 2.5: 1 Sodium malonate = 0.05 M Strippant = 2 % NaCl + 1 M HCl (4:1)
Solvent Dielectric constant, ε
Amount of Ru(III) extracted, % E
D
Xylene*
2.30 99.9 2497.5
Toluene
2.38 99.9 2497.5
Benzene
2.27 99.9 2497.5
Chloroform
4.80
No extraction
-
Amyl Alcohol
13.90 No extraction -
Amyl Acetate
4.80 No extraction -
Methyl iso butyl ketone (MIBK)
13.10
93.1
33.73
1,2- Dichloro ethane
10.50 No extraction -
n-Butyl alcohol
17.80
42.2
1.82
Carbon tetrachloride
2.24 No extraction -
* Recommended for general extraction procedure, D = Distribution Ratio % E = Percentage extraction
Chapter 3 – Solvent extraction studies of ruthenium(III) using high molecular weight amine
Analytical Chemistry Laboratory, Dept. of Chemistry, Shivaji University, Kolhapur 47
Table 3.6 Effect of stripping agents on ruthenium(III) extraction Ruthenium(III) = 200 µg pH = 3.5 Aq: org ratio = 2.5: 1 Extractant = 0.1 M n-octylaniline in xylene Sodium malonate = 0.05 M
Strripant
Concentration % E D
HCl
Concentrated (2×10 mL)
99.9
2497.5
HBr
Concentrated (2×10 mL)
99.9
2497.5
2 % NaCl+1 M HCl*
40 mL+10 mL
99.9
2497.5
Ammonia
7 M (3 × 10 mL) 34.5 1.31
Ammonia + NH4Cl
2 M + 3 M (2 × 10 mL)
43.0
1.88
NaOH
1 M (2 × 10 mL)
60.8
3.87
KOH
1 M (2 × 10 mL)
55.8
3.15
H2O
2x10mL
- -
NH4Cl 2%(3x10mL) 26.3 0.89
* Recommended for general extraction procedure % E = Percentage extraction of Ru(III) D = Distribution Ratio.
Chapter 3 – Solvent extraction studies of ruthenium(III) using high molecular weight amine
Analytical Chemistry Laboratory, Dept. of Chemistry, Shivaji University, Kolhapur 48
Table 3.7 Extraction behavior of ruthenium(III) as a function of equilibrium time
Ruthenium(III) = 200 µg pH =3.5 Sodium Malonate = 0.05 M Aq: org ratio = 2.5: 1 Extractant = 0.1 M n-octylaniline in xylene Strippant = 2 % NaCl +
1 M HCl (4:1)
Time in min
% E D
1 57.9
3.43
2 93.0
33.21
3 99.9
2497.5
4 99.9
2497.5
5*
99.9
2497.5
6 99.9
2497.5
7 99.9
2497.5
8 99.9
2497.5
9 99.9
2497.5
10 99.9
2497.5
12 99.9
2497.5
15 42.0
1.81
18 27.8 0.96
* Recommended for general extraction procedure % E = Percentage extraction of Ru(III) D = Distribution Ratio.
Chapter 3 – Solvent extraction studies of ruthenium(III) using high molecular weight amine
Analytical Chemistry Laboratory, Dept. of Chemistry, Shivaji University, Kolhapur 49
Table 3.8. Extraction behavior of ruthenium(III) as a function of metal
loading capacity pH =3.5 Extractant = 0.1 M n-octylaniline in xylene Sodium malonate = 0.05 M Aq: org ratio = 2.5: 1 Strippant = 2 % NaCl +
1 M HCl (4:1) Metal concentration in
μg/mL % E D
100
99.9
2497.5
200*
99.9
2497.5
300
99.9
2497.5
400
99.9
2497.5
500
99.9
2497.5
800 78.4 9.07
1000
72.4
6.55
1200
65.3
4.70
1500
50.2
2.52
1800
38.1 1.53
2000
32.2 1.18
* Recommended for general extraction procedure % E = Percentage extraction of Ru(III) D = Distribution Ratio.
Chapter 3 – Solvent extraction studies of ruthenium(III) using high molecular weight amine
Analytical Chemistry Laboratory, Dept. of Chemistry, Shivaji University, Kolhapur 50
Table 3.9 Extraction of ruthenium(III) as a function of aqueous
to organic volume ratio
Ruthenium(III) = 200 μg pH = 3.5 n-octylaniline = 0.1 M xylene Sodium malonate = 0.05 M Strippant = 2 % NaCl + 1 M HCl (4:1)
* Recommended for general extraction procedure
Aqueous to organic volume ratio
Percentage extraction,
( %E )
Distribution ratio, ( D )
10:10 99.9 2497.5
20:10 99.9 2497.5
25:10* 99.9 2497.5
30:10 99.9 2497.5
35:10 99.9 2497.5
40:10 99.9 2497.5
50:10 77.3 8.51
100:10 55.4 3.10
150:10 43.0 1.88
Chapter 3 – Solvent extraction studies of ruthenium(III) using high molecular weight amine
Analytical Chemistry Laboratory, Dept. of Chemistry, Shivaji University, Kolhapur 51
Table 3.10 Effect of foreign ions on the extraction of ruthenium(III)
Ruthenium(III) = 200 µg pH = 3.5 Extractant = 0.1 M n-octylaniline Aq: org ratio = 2.5: 1 Sodium malonate = 0.05 M in xylene Strippant = 2 % NaCl + 1 M HCl (4:1)
Tolerance limit, mg Foreign ion added
50 Tartrate, oxalate, fluoride, acetate
25 Bromide, EDTA, Mg(II)
15 Fe(III), Zn(II), Mo(VI), Se(IV), Ba(II),Ce(IV)
10 Ni(II), Co(II), U(VI), iodide, Hg(II)
5 Cu(II), Pb(II), Cr(VI), Bi(III), Te(IV),Cd(II)
2 Phosphate, Tl(I), Ca(II), Al(III), Cr(III), Cd(II),
1 Ag(I), Pt(IV), Os(VIII)
0.5 Rh(III)a,Pd(II) a,Ir(III)b,Au(III)c
a = masked by 25 mg tartrate, b= masked by 25 mg oxalate, c = masked by 10 mg bromide
Chapter 3 – Solvent extraction studies of ruthenium(III) using high molecular weight amine
Analytical Chemistry Laboratory, Dept. of Chemistry, Shivaji University, Kolhapur 52
Table 3.11 Separation of ruthenium(III) from binary mixtures
Metal ions Amount taken, µg
Average recovery*, %
Chromogenic ligand References
Ru(III)
Pt(IV)
200
300
99.8
99.2
-
SnCl2
[55]
Ru(III)
Pd(II)a
200
200
99.8
99.7
-
4’-ChloroPTPT
[54]
Ru(III)
Ir(III)b
200
100
99.8
98.6
-
SnCl2 - HBr
[55]
Ru(III)
Rh(III)a
200
200
99.8
99.7
-
SnCl2 +KI
[55]
Ru(III) Os(VIII)
200 200
98.0 99.3
Thiourea
[55]
Ru(III)
Au(III)c
200
200
99.8
98.8
-
SnCl2
[55]
Ru(III)
Co(II)
200
1000
99.7
98.8
-
Thiocyanate
[57]
Ru(III)
Ni(II)
200
5000
99.8
98.8
-
DMG
[57]
Ru(III)
Cu(II)
200
2000
99.8
98.8
-
4’-ChloroPTPT
[56]
Ru(III)
Fe(III)
200
1000
99.7
98.8
-
Thiocyanate
[55]
Ru(III)
Se(IV)
200
300
99.8
98.8
-
4’-BromoPTPT
[58]
Ru(III)
Te(IV)
200
200
99.8
98.8
-
4’-BromoPTPT
[59]
* Average of six determinations. a = masked by 25 mg tartrate, b= masked by 25 mg oxalate, c = masked by 10 mg bromide
Chapter 3 – Solvent extraction studies of ruthenium(III) using high molecular weight amine
Analytical Chemistry Laboratory, Dept. of Chemistry, Shivaji University, Kolhapur 53
Table 3.12 Separation of ruthenium(III) from ternary mixture
Metal ion
Amount taken,
µg
Aqueous phase (25 mL)
Stripping agent
Determination method
Recovery percentage*
Ru(III) 200 0.05 M
malonate
pH = 3.5
2 % NaCl +
1 M (4:1)
4’-
ChloroPTPT
[54]
99.8
Rh(III)a 200 0.03 M
malonate
pH = 9.0
1 M HCl
(2 × 10 mL)
SnCl2 + KI
[55]
99.7
Pd(II)a 200 0.085 M
salicylate
pH = 1.5
5 M
(3 × 10 mL)
4’-
ChloroPTPT
[54]
99.7
a = masked by 25 mg tartrate *= Average of six determination
Chapter 3 – Solvent extraction studies of ruthenium(III) using high molecular weight amine
Analytical Chemistry Laboratory, Dept. of Chemistry, Shivaji University, Kolhapur 54
Table 3.13. Determination of ruthenium(III) from synthetic mixture
corresponding to alloys
Synthetic mixture Ruthenium
(III) found, µg
Amount of Ru(III) extracted,
%
RSD, % Ions Metal ion
taken, µg Ru(III)
Pd(II)a
Pt(IV)
200
100
100
197.0 98.5 1.5
Ru(III)
Ir(III)b
Rh(III)a
200
100
100
198.7 99.3 0.7
Ru(III)
Ni(II)
Au(III)c
200
100
100
197.0 98.5 1.5
Ru(III)
Co(III)
Fe(III)
200
200
200
198.7 99.3 0.7
Ru(III)
U(VI)
Th(IV)
200
100
100
197.5 98.7 1.3
a = masked by 25 mg tartrate, b= masked by 25 mg oxalate, c = masked
by 10 mg bromide
Chapter 3 – Solvent extraction studies of ruthenium(III) using high molecular weight amine
Analytical Chemistry Laboratory, Dept. of Chemistry, Shivaji University, Kolhapur 55
Table 3.14. Determination of ruthenium(III) from catalysts
Sample of catalyst (Lancaster make)
Amount of Ru(III) taken, µg
% Recovery of Ru(III)
RSD, %
Ruthenium 5 % on carbon
200 99.7
0.3
Ruthenium 10 % on carbon
200 99.3
0.7
Ruthenium 5 % on alumina
200 99.5
0.5
Chapter 3 – Solvent extraction studies of ruthenium(III) using high molecular weight amine
Analytical Chemistry Laboratory, Dept. of Chemistry, Shivaji University, Kolhapur 56
0
10
20
30
40
50
60
70
80
90
100
0 1 2 3 4 5 6 7 8 9 10
pH
Perc
enta
ge E
xtra
ctio
n (%
E)
Fig. 3.1 Plot of pH versus percentage extraction of ruthenium(III)
(200 μg/mL) from malonate medium (0.05 M) by using
n-octylaniline (0.1 M) as an extractant in xylene with 5 min
shaking time.
Chapter 3 – Solvent extraction studies of ruthenium(III) using high molecular weight amine
Analytical Chemistry Laboratory, Dept. of Chemistry, Shivaji University, Kolhapur 57
0
10
20
30
40
50
60
70
80
90
100
0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1 0.11 0.12 0.13
n-octyaniline (M)
Perc
enta
ge e
xtra
ctio
n (%
E)
Fig. 3.2 Extraction of ruthenium(III) (200 µg/mL) at pH 3.5 from
0.05 M sodium malonate as a function of n-octylaniline
concentration.
Chapter 3 – Solvent extraction studies of ruthenium(III) using high molecular weight amine
Analytical Chemistry Laboratory, Dept. of Chemistry, Shivaji University, Kolhapur 58
0
10
20
30
40
50
60
70
80
90
100
0 0.02 0.04 0.06 0.08 0.1
Weak Acid (M)
Perc
enta
ge E
xtra
ctio
n (%
E)
Sodium malonate
Sodium succinate
Sodium salicy late
Fig 3.3 Extraction of ruthenium(III) (200 µg/mL) at pH 3.5 with
0.1 M n-octylaniline as a function of weak organic acid
concentration.
Chapter 3 – Solvent extraction studies of ruthenium(III) using high molecular weight amine
Analytical Chemistry Laboratory, Dept. of Chemistry, Shivaji University, Kolhapur 59
0
10
20
30
40
50
60
70
80
90
100
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
Time in min.
Perc
enta
ge e
xtra
ctio
n (%
E)
Fig. 3.4 Extraction of ruthenium(III) (200 µg/mL) at pH 3.5 from
0.05 M sodium malonate as a function of equilibration
period.
Chapter 3 – Solvent extraction studies of ruthenium(III) using high molecular weight amine
Analytical Chemistry Laboratory, Dept. of Chemistry, Shivaji University, Kolhapur 60
▲ Slope = 1.0 at pH 5
■ Slope = 0.99 at pH 6
-0.4
-0.3
-0.2
-0.1
0
0.1
0.2
0.3
0.4
0.5
0.6
-1.8 -1.7 -1.6 -1.5 -1.4 -1.3 -1.2 -1.1 -1
Log C [n-octylaniline]
Log
D[R
u(II
I)]
Fig. 3.5 Log-log plot of distribution ratio Log D[Ru(III)] versus
Log C[n-octylaniline] at fixed malonate concentration.
Chapter 3 – Solvent extraction studies of ruthenium(III) using high molecular weight amine
Analytical Chemistry Laboratory, Dept. of Chemistry, Shivaji University, Kolhapur 61
▲ Slope = 2.0 at pH 5
■ Slope = 1.75 at pH 6
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
-1.9 -1.8 -1.7 -1.6 -1.5 -1.4 -1.3 -1.2 -1.1 -1Log C [Malonate]
Log
D[R
u(II
I)]
Fig. 3.6 Log-log plot of distribution ratio Log D[Ru(III)] versus Log C[malonate]
at fixed n-octylaniline concentration.
Chapter 3 – Solvent extraction studies of ruthenium(III) using high molecular weight amine
Analytical Chemistry Laboratory, Dept. of Chemistry, Shivaji University, Kolhapur 62
References
[1] J. A. Rard, Chemistry and thermodynamics of europium and some of its
simpler inorganic compounds and aqueous species, Chem. Rev., 85
(1985) 555.
[2] C. R. Hamond, The elements in Lide, D. R., ed., CRC Handbook of
chemistry and Phycsics, 86th Edition, Boca Raton (FL), CRC press,
2005.
[3] A. D Richards, A. Rodger, Synthetic metallomolecules as agents for the
control of DNA structure, Chem. Soc. Rev., 36 (2007) 471.
[4] K. Daibin, I. Seigo, W. Bernard, K. Cedric, M. Jacques-E, H. Baker,
R. Zakeeruddin, M. Shaik, G. Michael, High molar extinction
coefficient heteroleptic ruthenium complexes for thin flim dyes –
sensetized solar cell, American Chemical Society, 128 (2006) 4146.
[5] K. R. Seddon, A Dance to the music of time, Platinum Metals Review,
40 (1996) 128.
[6] S. Atak, M. S. Celik, Innovations in mineral and coal processing, Taylor
and Francis 1998.
[7] S. Karlsson, International directory of radioisotopes, 2nd Edition,
International Atomic Energy Agency, Vienna, 1962.
[8] T. C Lo, M. H. Baird, C. Hanson, Handbook of Solvent Extraction,
wiley Interscience, New York, 1983.
[9] T. M. Bahrainwala, Z. R. Turel, Solvent extraction of Ru(III)
2-mercaptobenzimidazole into n-butanol, J. Radioanal. Nucl. Chem.,
237 (1998) 175.
[10] V. Druskovic, V. Vojkovic, T. Antonic, Extraction of ruthenium and its
separation from rhodium and palladium with 4-pyridone derivatives,
Croat. Chem. Acta., 78 (2005) 617.
[11] A. Mhaske, P. Dhadke, Extraction sepration studies of Os, Ru and Ir
using Cyanex 921 in touene, Hydrometallurgy, 63 (2002) 207.
[12] S. Kedari, M. T. Coll, A. Fortuny, E. Goralska, A. M. Sastre, Liquid-
liquid extraction of Ir, Ru, and Rh from chloride solutions and their
Chapter 3 – Solvent extraction studies of ruthenium(III) using high molecular weight amine
Analytical Chemistry Laboratory, Dept. of Chemistry, Shivaji University, Kolhapur 63
separation using different commercially available solvent extraction
reagents, Sep. Sci.Technol., 40 (2005) 1927.
[13] M. Mojski, Extraction of platinum metals from hydrochloric acid
medium with triphenylphosphine solution in 1,2-dichloroethane,
Talanta, 27 (1980) 7.
[14] G. Yan, J. Aistad, Solvent extraction of rhodium, ruthenium and iridium
with HDEHP, J. Radioanal. Nucl. Chem., 201 (1995) 191.
[15] G. Yan, J. Aistad, Sepration of rhodium from ruthenium and iridium by
fast solvent extraction with HDEHP, J. Radioanal. Nucl. Chem., 196
(1995) 287.
[16] A. M. Rozen, N.A. Kartasheva, Z. N. Nikolotova, Extraction of
nitrosoruthenium by tributyl phosphate, Radiokhimiya, 37 (1995) 232.
[17] S. A. Pai, J. P. Shukla, M. S. Subramanian, Extraction behavior of
uranium, zirconium and ruthenium with γ-irradiated sulfoxides and tri-n-
butyl phosphate, J. Radioanal. Nucl. Chem., 78 (1982) 31.
[18] S. Akira, I. Tatsuo, K. Fumio, Re-extraction behavior of nitrosyl
ruthenium complex in tributyl phosphate-dodecane solvent system, Bull.
Chem. Soc. Jpn., 60 (1987) 4160.
[19] Z. Guohui, H. Haoxin, H. Shubin, L. Lanzhen, Extraction of nitrosyl
ruthenium complexes with γ-irradiated tributyl phosphate- kerosine,
Yuanzineng Kexue Jishu, 22 (1988) 257.
[20] J. N. Mathur, M. S. Murli, P. R. Natarajan, L. P. Badheka, A. Banerji,
Extraction of actinides and fission products by octyl(phenyl)-N,N-
diisobutylcarbamoylmethyl-phosphine oxide from nitric acid media,
Talanta, 39 (1992) 493.
[21] E. L. Smith, E. J. page, The acid-binding properties of long-chain
aliphatic amines, J. Soc. Chem. Ind., 67 (1948) 48.
[22] E. Goralska, M. T. Coll, A. Fortuny, C. S. Kedari, A. M. Sastre, Studies
on the selective separation of Ir(IV), Ru(III) and Rh(III) from chloride
solutions using alamine 336 in kerosene, Solvent Extr. Ion Exch., 25
(2007) 65.
Chapter 3 – Solvent extraction studies of ruthenium(III) using high molecular weight amine
Analytical Chemistry Laboratory, Dept. of Chemistry, Shivaji University, Kolhapur 64
[23] M. Y. Mirza, Studies on the extraction of platinum metals with tri-iso-
octylamine from hydrochloric and hydrobromic acid: Separation
and determination of gold, palladium and platinum, Talanta, 27 (1980)
101.
[24] T. M. Buslaeva, I. V. Malynov, N. A. Koteneva, N. M. Sinitsyn, V. V.
Kravchenko, Complexation during extraction of ruthenium chloro
complexes by trioctylamine oxide, Zh. Neorg. Khim., 35 (1990) 1978.
[25] V. Bakurdzhieva, N. Ivanov, Extraction of thiocyanate complexes of
ruthenium by bis(2-ethylhexyl)amine and its analytical application, Zh.
Anal. Khim., 44 (1989) 899.
[26] J. Lingen, L. Shiyan, P. Gang, Extraction of ruthenium(IV) with mixed
solvents, He Huaxue Yu Fangshe Huaxue, 9 (1987) 241.
[27] T. N. Lokhande, G. B. Kolekar, M. A. Anuse, M. B. Chavan, Extraction
of ruthenium(IV) from hydrochloric acid medium with N-octylaniline
and its determination spectrophotometrically with pyrimodine-2-thiol,
Sep. Sci. Technol., 35 (2000) 153.
[28] P. Malik and A.P. Paiva, Liquid-liquid extraction of ruthenium from
chloride media by N,N’-dimethyl-NN’-dicyclohexylmalonamide,
Solvent Extr. Ion Exch., 39 (2011) 176.
[29] J. Lingen, L. Shiyan, P. Gang, Studies on the state and the solvent
extraction property of Ru(IV) in hydrochloric acid solution, He Huaxue
Yu Fangshe Huaxue, 7 (1985) 206.
[30] V. N. Mitkin, A. A. Vasileva, T. M. Korda, S. V. Zemskov, V. G.
Torgov, A. N Tatarchuk, Sample digestion by liquid-phase oxidative
fluorination with bromine trifluoride in determination of noble metals,
Zh. Anal. Khim., 44 (1989) 1589.
[31] K. A. Bolshakov, N.M. Sinitsyn, T. M. Buslaeva A.P Ivchenko,
Characteristics of ruthenium(III) extraction by primary amines, Dokl.
Akad. Nauk SSSR, 251 (1980) 1406.
[32] V. V. Belova, A. A. Vasileva, N. V. Androsova, Extraction-atomic-
absorption determination of iridium, ruthenium, and rhodium in sulfate
Chapter 3 – Solvent extraction studies of ruthenium(III) using high molecular weight amine
Analytical Chemistry Laboratory, Dept. of Chemistry, Shivaji University, Kolhapur 65
solutions, Izvestiya Sibirskogo Otdeleniya Akademii Nauk SSSR,
Seriya Khimicheskikh Nauk, 1 (1983) 89.
[33] A. A. Vasileva, T. M. Korda, V. G. Torgov, A. N. Tatarchuk, Fire-
assay- extraction preconcentration of platinum-group metals in the
analysis of product of complex composition, Zh. Anal. Khim., 46
(1991) 1293.
[34] V. G. Torgov, M. G. Demidova, T. M. Korda, T. M. Korda, N. K.
Kalish, R. S. Shulman, Extraction – atomic absorption spectrometric
method for the determination of PGMs and gold in copper-nickel ores
using autoclave sample decomposition technique, Analyst, 121 (1996)
489.
[35] Yu. M. Yukhin, T. A. Udalova and V. G. Tsimbalist, Flameless atomic
absorption determination of noble metals after liquid-liquid extraction
by a mixture of bis(2-ethyl-hexyl)dithiophosphate and p-octylaniline,
Zh. Anal. Khim., 40 (1985) 850.
[36] V. V. Belova, A. A. Vasileva, R. S. Shulman, Study of the extraction of
sulfate complexes of platinum, palladium, and ruthenium by
p-octylaniline, Deposited Doc. (1980), (VINITI 1683-80) p. 26.
[37] S. Li, X. Sun, Determination of trace ruthenium in the large amount of
iridium by extraction-graphite furnace AAS, Guangpuxue Yu. Guangpu
Fenxi, 10 (1990) 61.
[38] J. Lingen, L. Shiyan, F. Li, Separation of ruthenium from uranium by
trialkylamine (N235) extraction, He Huaxue Yu Fangshe Huaxue,
10 (1988) 188.
[39] M. Hoashi, R. R. Brooks, R. D. Reeves, Graphite furnace atomic
absorption spectrometric determination of ruthenium in iron meteorites
Anal. Chim. Acta, 232 (1990) 317.
[40] M. Oddone, S. Melonia, R. Vannucci, An accurate procedure for the
determination of low levels of platinum group elements in slandered
materials by neutron activation analysis, J. Radioanal. Nucl. Chem., 142
(1990) 489.
Chapter 3 – Solvent extraction studies of ruthenium(III) using high molecular weight amine
Analytical Chemistry Laboratory, Dept. of Chemistry, Shivaji University, Kolhapur 66
[41] O. X. Rong, W. J. Duan, H. R. Li, R. N. Chen, S. Q. Liu, J. L. Ye, Z.
Huang, X. H. Gu, Extraction of thiocyanate complexes of platinum ions
by MIBK, Fenxi Shiyanshi, 13 (1994) 37.
[42] M. Kenj, Removal of ruthenium. from purex process, (II) fundamental
research of electrolytic oxidation of ruthenium, J. Nucl. Sci. Technol.,
27 (1990) 262.
[43] Z. Aneva, S. Arpadyan, I. Kalaidzhieva, Graphite furnace atomic
absorption spectrometric determination of iridium, rhodium and
ruthenium in high-purity platinum after matrix extraction, Anal. Chim.
Acta., 236 (1990) 385.
[44] K. H. Koenig, M. Schuster, B. Steinbrech, G. Schneewis, R. Schlodder,
Process for separation and purification of platinum group metals (I),
Fresnius Z. Anal. Chem., 321 (1985) 457.
[45] P. Vest, M. Schuster and K. H. Koenig, Solvent extraction of platinum
metals N-mono and N,N-di-substituierten benzoylthiourea, Fresenius Z.
Anal. Chem., 335 (1989) 759.
[46] E. Jackson, The solvent extraction behaviour of ruthenium with p-50
oxziwe in aqueous nitrate solutions, Miner. Eng., 9 (1996) 469.
[47] C. H. Shen, B. R. Bao, Y. Z. Bao, G.D. Wang, J. Qian, Z. B. Cao,
Extraction of U(VI), Th(IV) and some fission products from nitric acid
medium by sulfoxides and effect of γ-irradiation on the extraction, J.
Radioanal. Nucl. Chem., 178 (1994) 91.
[48] F. E. Beamish, J. C. Van Loon, Analysis of Noble Metals: Overview and
Selected Methods, Academic Press INC, London, 1977.
[49] R. A. Mathes, F. D. Stewart and F. J. Swedish, A synthesis of
2-pyrimidinethiols, J. Am. Chem. Soc., 70 (1948) 1452.
[50] R. A. Mathes and F. D. Stewart, Thiazoline, pyrimidine and thiazine
ring compounds with acid substituents attaahed to the nitrogen, J. Am.
Chem. Soc., 72 (1950) 1879.
[51] R. A. Mathes and F. D. Stewart, 2-Mercapto-3-amino-3,6-dihydro-
pyrimidines, U. S. Patent, 26 (1950) 535.
Chapter 3 – Solvent extraction studies of ruthenium(III) using high molecular weight amine
Analytical Chemistry Laboratory, Dept. of Chemistry, Shivaji University, Kolhapur 67
[52] R. A. Mathes, 2-Pyrimidinethiols, J. Am. Chem. Soc., 75 (1953) 1747.
[53] C. Pohlandt, The extraction of noble metals with n-octylaniline, Talanta,
26 (1979) 199.
[54] M. A. Anuse, M. B. Chavan, Studies on extraction separation of
platinum metals and gold(III) with pyrimidinethiol: Spectrophotometric
determination of palladium(II), osmium(VIII), and ruthenium(III),
Chem. Anal., (Warsaw) 29 (1984) 409.
[55] E. B. Sandell, Colorimetric determination of traces of metals, 3rd Ed.
Interscience, New York, 1965, pp 503, 519, 702, 774, 781, 524.
[56] M. A. Anuse, S. R. Kuchekar, M. B. Chavan, 1-(4-Chlorophenyl)-4,4,6-
trimethyl-1,4- dihydropyrimidine-2thiol as an effective reagent for the
spectrophotometric determination of copper after synergic extraction,
Indian J. Chem., 25 A (1986) 1041.
[57] Zygmunt Marczenko, Spectophotometric determination of elements,
Ellis Horwood Limited, Chichester, 1976, pp 229, 370.
[58] G. B. Kolekar, M. A. Anuse, Extractive spectrophotometric
determination of selenium(IV) using 1-(4’-bromophenyl)-4,4,6-
trimethyl- 1,4- dihydropyrimidine 2-thiol, Res. J. Chem. Environ., 2
(1998) 9.
[59] G. B. Kolekar, M. A. Anuse, Extraction, separation and
spectrophotometric determination of tellurium(IV) with 1-(4’-
bromophenyl)-4,4,6-trimethyl-1,4-dihydropyrimidine 2-thiol, Bull.
Chem. Soc. Jpn., 71 (1998) 859.