Extraction Of Lanthanum, Cerium, Neodimium With Di-n-buthyldithiocarbamate (Dbdtc) As Chelating Extractant And Analysis Using Inductively Coupled Plasma - Optical Emission Spectroscopy (Icp-oes).
S.A. Afrillya et al.
ISBN 978-979-18962-0-7
Proceeding of The International Seminar on Chemistry 2008 (pp. 186-190)
Jatinangor, 30-31 October 2008
Extraction of lanthanum, cerium, neodimium with
di-n-buthyldithiocarbamate (DBDTC) as chelating extractant and analysis
using inductively coupled plasma - optical emission spectroscopy
(ICP-OES)
Sistri Arda Afrillya*, Yayah Mulyasih, Iwan Hastiawan
Inorganic Laboratory, Department of Chemistry, Faculty of Mathematics and Natural Sciences,
Padjadjaran University, Sumedang, West Java, Indonesia 45363
*e-mail: [email protected]
Abstract
Monazite is a reddish brown phosphate. Rare Earth Elements (REEs) exist in monazite and can be
separated by using solvent extraction method. The objects of this research are to investigate the
optimum condition to extract La, Ce and Nd complex with high recovery at pH 2.0, 3.5, 4.0, 4.5, 5.0,
5.5 and 6.0, in organic solvents toluene, diethyl ether and petroleum ether, and also to analyze the
elements concentration of the aqueous phase with instrument inductively Couple Plasma – Optical
Emission Spectroscopy (ICP-OES). This solvent extraction method used di-n-butyldithiocarbamat
(DBDTC) as chelating extractant that the complex formed is extracted to organic phase. Di-nbutilditiocarbamat (DBDTC) was prepared by reacting carbon disulfide and di-n-buthylamine, then
the La, Ce and Nd standard solution was prepared by diluting their oxides to diluted nitric acid and
diluted to appropriate buffer solution. Each standard solution was extracted with organic solvents
toluene/diethyl ether/petroleum ether by adding DBDTC 1% solution 1:3 in metal (mole) : ligand
(mole) comparison. After that, the aqueous phases were analyzed using instrument ICP-OES. La/NdDBDTC complex can be best extracted using organic solvent diethyl ether at pH 5.5 with Kd for LaDBDTC and Nd-DBDTC are 1.1870 and 0.6274. Ce-DBDTC complex can be best extracted using
solvent diethyl ether at pH 2.0 with Kd 0.9109. Instrument ICP-OES is good for standard solution
and organic phase concentration analyzing.
Keywords: Di-n-buthyldithiocarbamate, ICP-OES, REE, Solvent Extraction, Diethyl ether
introduced two computer speaker systems that use
neodymium and blend the art of sound with the beauty
of design (Fox et al., 2001).
Inductively Coupled Plasma-Optical Emission
Spectroscopy (ICP-OES) is one of several techniques
available in analytical atomic spectroscopy. ICP-OES
utilizes a plasma as the atomization and excitation
source. A plasma is an electrically neutral, highly
ionized gas that consists of ions, electrons, and atoms.
The sun, lightning, and the aurora borealis are
examples of plasmas found in nature. The energy that
maintains an analytical plasma is derived from an
electric or magnetic field; they do not “burn”
(Manning and Grow, 1997).
In the present study, extraction of La, Ce and Nd
with DBDTC as chelating extractant using organic
solvents toluene, diethyl ether and petroleum ether,
and also metals analysis using ICP-OES have been
studied.
Introduction
Rare earth elements are a series of chemical elements
of the periodic table, including the elements with
atomic numbers 57 through 71, and, named in order,
are lanthanum (La), cerium (Ce), praseodymium (Pr),
neodymium (Nd), promethium (Pm), samarium (Sm),
europium (Eu), gadolinium (Gd), terbium (Tb),
dysprosium (Dy), holmium (Ho), erbium (Er), thulium
(Tm), ytterbium (Yb), and lutetium (Lu). Yttrium (Y,
atomic no. 39) and scandium (Sc, atomic no. 21) are
sometimes included in the group of rare earth
elements. The elements cerium (Ce, atomic no. 58)
through lutetium (Lu, atomic number 71) are
commonly known as the lanthanide series (Krakew et
al., 2005).
They are essential in many and relevant
applications in chemical, metallurgical, optical,
electronic and ceramic products. In several of these
uses, the rare-earths are responsible for high
technological performances, either by participating in
the intermediate manufacturing processes or
integrating the finished products (Masson & Osvaldo,
2002). Altec Lansing Technologies, Inc., a leader in
the market for personal computer speakers, has
186
S.A. Afrillya et al.
Proceeding of The International Seminar on Chemistry 2008 (pp. 186-190)
Jatinangor, 30-31 October 2008
fungsional group. Peaks at υ 2956 cm-1 - 2775 cm-1 is
for C-H vibration from C4H9. Peak at υ 1554 cm-1 is
for C=N stretch from electron delocalization with C=S
fungsional group. Peak at υ 1462 cm-1 is from C=S
vibration bonded to nitrogen. Peak at υ 1398 cm-1 is
for CH3 symmetry vibration from C4H9. Peaks at υ
1282 cm-1-1190 cm-1 come from C-N stretch. Peaks at
υ 1130 cm-1 - 1103 cm-1 come from C=S stretch.
Peaks at υ 732 cm-1 - 524 cm-1 (finger print area)
come from C-S stretch.
Materials and Method
Materials
La2O3, CeO2 and Nd2O3 (Aldrich, 99,99%) were used
as REEs standard and diluted nitric acid was used to
dilute them. CS2, di-n-buthylamine and ammonia were
used to prepare DBDTC. Acetic acid, sodium acetic,
hydrochloride acid and kalium chloride were used to
prepared the varied buffer solutions. Toluene, diethyl
ether and petroleum ether were used as organic
solvents.
Extraction of La, Ce and Nd with DBDTC
Apparatus
Some researches of Krakew et al. (2005) and
Atanassova et al. (2006-2007) about REEs extraction
using mixtures of varied two extractants and several
organic solvents, show that uses of certain chelating
extractant and organic solvent need certain condition
for each REEs in order to be extracted with high
recovery. So, in this study, La, Ce and Nd standard
solution were prepared in varied pH.
La and Nd extraction were carried out at pH 4.0;
4.5; 5; 5.5; and 6 because light REEs were extracted
with high recovery in acidic condition. Ce extraction
was carried out at pH 2.0 and 3.5 because cerium
oxide formed its hydroxide precipitate at pH above
3.5.
DBDTC was used as chelating extractant that La,
Ce and Nd complex are extracted to organic solvents.
The mole comparison of metal and chelating
extractant was 1:3 because it can best extract the light
REEs complex. Toluene, diethyl ether and petroleum
ether were used as organic solvents to solve the
complex formed in extraction process. After
separation of the phases, the metal concentration of
aqueous phase was determined using ICP-OES.
La and Nd can be extracted with the highest
recovery at pH 5.5 using diethyl ether. Kd of LaDBDTC and Nd-DBDK at this condition are 1.1870
and 0.6274. Ce can be extracted with the highest
recovery using the same solvent at pH 2. Kd of CeDBDTC at this condition is 0.9109. Kd values of the
elements extraction are shown in figure 3, 4 and 5.
Digital pH-meter Mettler Toledo MP 220 was used
for the pH measurements, spectrophotometer UV-Vis
Ultrospec 3000 pro and spectrophotometer IR for
spectrophotometric measurements, and ICP-OES
Varian Vista MX for metal concentration analysis
spectrometrically.
Methods
DBDTC was prepared by reacting CS2, di-nbuthylamine and ammonia at 0 0C, stirred
continuously for about 30 minutes until permanent
precipitate occurred. The precipitate was separated
from the liquid and dried at room temperature.
La, Ce and Nd standard solutions were prepared
by diluting their oxide in diluted nitric. Then, the
extraction of each standard solution was carried out in
separatory funnel containing 10 mL aqueous and
organic phase. The samples were shaken for 10
minutes and stood for 10 minutes at room
temperature. After the separation of the phases, the
metal concentration in aqueous phase was determined
spectrometrically using ICP-OES.
Results and Discussion
DBDTC Characterization
DBDTC is not stored in the market, so in this study,
the chelating agent was synthesized as its ammonium
salt. This compound is melted at 42 – 46 0C, solved in
methanol and dissolved in water. Figure 1 shows the
UV-Vis spectra of DBDTC at 200-800 nm and Figure
2 shows IR spectra of ammonium-DBDTC.
The UV-Vis spectra show two peaks at 315 nm
and 357 nm, which are considered as π to π* and n to
π* transition absorption. The π to π* transition is
appeared because of C=S double bond and n to π*
transition is appeared because of lone pair electron in
S atom that absorbs light at 250-380 nm.
The IR spectra show us several peaks. Peak at υ
3450 cm-1 is for N-H stretch from ammonium
Analysis using Inductively Coupled Plasma – Optical
Emission Spectroscopy (ICP-OES)
Each atom has several energy levels. Atoms emit
electromagnetic radiation as they relax from an
excited state to their ground state. The emitted
radiation can be easily detected when it is in the
vacuum ultraviolet (VUV, 120-185 nm), ultraviolet
(UV, 185-400 nm), visible (VIS, 400-700 nm), and
near infrared regions (NIR, 700-850 nm).
187
S.A. Afrillya et al.
Proceeding of The International Seminar on Chemistry 2008 (pp. 186-190)
Jatinangor, 30-31 October 2008
4, 000
Abs
3, 000
li gan DBDTK
1
2, 000
1, 000
0, 000
20 0,0
40 0,0
Wa velength (nm)
60 0,0
80 0,0
Figure 1 UV-Vis Spectra of ammonium di-n-buthyldithiocarbamate in methanol
Figure 2 IR spectra of ammonium di-n-dibuthyldithiocarbamate
Figure 3 Kd of La-DBDTC extraction with toluene, diethyl ether and petroleum ether versus pH
Figure 4 Kd of Nd-DBDTC extraction with toluene,
diethyl ether and petroleum ether versus pH
Figure 5 Kd of Ce-DBDTC extraction with toluene,
diethyl ether and petroleum ether versus pH
188
S.A. Afrillya et al.
Proceeding of The International Seminar on Chemistry 2008 (pp. 186-190)
Jatinangor, 30-31 October 2008
Figure 6 Steps involved in the analysis of aqueous samples by ICP-OES (Manning & Grow, 1997)
because they absorb energy from plasma. Then, the
detector will detect the emission of radiation upon
relaxation from an excited state of the atoms.
Every element absorbs light in more than one wave
lengths, so we have to find the optimum wavelength to
obtain the elements’ concentration using ICP-OES.
This wavelength optimizing was done by observing
the intensities of the elements’ standard solutions at 20
various wavelengths. In this study, lanthanum oxide,
cerium oxide and neodymium oxide was used to
prepare the standard solutions with various
concentrations, 0.1, 0.2, 0.5, 1, 2, 5, 10, 20, 50, and
100 ppm. The graphic of standard solution has to be
linear in order to be able to use in the sample
concentration determination. There are several wave
lengths which give linear graphics, so we have to
choose one of the wave lengths that give the highest
intensities and less interferences for certain element.
The optimum wave lengths for La, Ce and Nd are
408.671, 401.239 and 430,357 nm.
Conclusions
La and Nd can be extracted with the highest
recovery at pH 5.5 using diethyl ether; Kd of La and
Nd at this condition are 1.1870 and 0.6274. Ce can be
extracted with the highest recovery at pH 2 using
diethyl ether; Kd of Ce at this condition is 0.9109.
ICP-OES is good for La, Ce and Nd extraction
analysis.
Acknowledgements
The authors are grateful to Laboratory Sucofindo
SBU JUM Cibitung for ICP-OES Analysis.
Coupled Plasma – Optical Emission Spectroscopy
(ICP-OES) Principles
References
The ICP-OES principles are electric and magnetic
fields, and detection of the radiation emissions by
detector. A plasma is an electrically neutral, highly
ionized gas that consists of ions, electrons, and atoms.
Argon is usually used as plasma that is used as the
atomization and excitation source (Gassing, 2005).
There are six steps involved in the analysis of
aqueous samples by ICP-OES as shown in the figure
6. Plasma temperature used is 10.000 K because at
this temperature chemical bonds of any compounds
can be broken. There are only atoms that will excite
Atanassova, M. 2006. Effect of the 18-Crown-6 and
Benzo-18-Crown-6 on the Solvent Extraction and
Separation of Lanthanoids(III) Ions with 8Hydroxyquinoline. Russian Journal of Inorganic
Chemistry. 52 (8), 1304-1311.
Atanassova, M. 2006. Solvent Extraction and
Separation of Lanthanoids with Mixture of
Chelating Extractant and 4-(2-pyridylazoresorcin. Proc. Estonian Acad. Sci. Chem. 55 (4),
202-211.
189
S.A. Afrillya et al.
Proceeding of The International Seminar on Chemistry 2008 (pp. 186-190)
Jatinangor, 30-31 October 2008
OES Variant Vista MPX. Skripsi. Universitas
Nusa Bangsa. Bogor.
Manning, T.J. & W.R. Grow. 1997. Inductively
Coupled Plasma – Atomic Emissio Spectrometry.
Springer-Verlag New York, Inc. New York.
Masson, I.O.C. & Osvaldo G.C.C. 2002. Extraction
of Heavy Rare-Earths dan Yttrium with a
Phosphonic Solvent. Contribuição Técnica aos
Anais da Associação Brasileira de Química,
51(1),1-8.
Kraikaew, J., Wanne S. & Chavlek C. 2005.
Solvent Extraction Study of Rare Earth from
Nitrate Medium by the Mixture of TBP and
D2EHPA in Kerosene. Chemistry and Material
Science
Research
Program.
Bangkok.
Atanassova, M. & Dukov, I.L. 2006. Synergistic
Solvent Extraction of Trivalent Lanthanoids with
mixture
of
1-Phenyl-3-methyl-4-benzoyl-5pyrazolone and Crown Ethers. Acta Chim. 53,
xxx-xxx.
Atanassova, M., Victoria L., Nikolay V., Sabi V., &
Ivan D. 2006. Effect of p-tert-Butylcalix[4]arene
Fitted with Phosphinoyl Pendant Arms as
Synergistic Agent in the Solvent Extraction and
Separation of some Trivalent Lanthanoids with 4Benzoyl-3-methyl-1-phenyl-5-pyrazolone.
Journal of Inclusion Phenomena and Macrocyclic
Chemistry
Fox, G., Myra P., Louise R. & Rich V. 2001.
Elements. High Tech Materials. Colorado.
Gassing. 2005. Kajian Panjang Gelombang yang
Sesuai untuk Analisa 23 Unsur Logam secara
Simultan dengan Menggunakan Instrument ICP-
190
ISBN 978-979-18962-0-7
Proceeding of The International Seminar on Chemistry 2008 (pp. 186-190)
Jatinangor, 30-31 October 2008
Extraction of lanthanum, cerium, neodimium with
di-n-buthyldithiocarbamate (DBDTC) as chelating extractant and analysis
using inductively coupled plasma - optical emission spectroscopy
(ICP-OES)
Sistri Arda Afrillya*, Yayah Mulyasih, Iwan Hastiawan
Inorganic Laboratory, Department of Chemistry, Faculty of Mathematics and Natural Sciences,
Padjadjaran University, Sumedang, West Java, Indonesia 45363
*e-mail: [email protected]
Abstract
Monazite is a reddish brown phosphate. Rare Earth Elements (REEs) exist in monazite and can be
separated by using solvent extraction method. The objects of this research are to investigate the
optimum condition to extract La, Ce and Nd complex with high recovery at pH 2.0, 3.5, 4.0, 4.5, 5.0,
5.5 and 6.0, in organic solvents toluene, diethyl ether and petroleum ether, and also to analyze the
elements concentration of the aqueous phase with instrument inductively Couple Plasma – Optical
Emission Spectroscopy (ICP-OES). This solvent extraction method used di-n-butyldithiocarbamat
(DBDTC) as chelating extractant that the complex formed is extracted to organic phase. Di-nbutilditiocarbamat (DBDTC) was prepared by reacting carbon disulfide and di-n-buthylamine, then
the La, Ce and Nd standard solution was prepared by diluting their oxides to diluted nitric acid and
diluted to appropriate buffer solution. Each standard solution was extracted with organic solvents
toluene/diethyl ether/petroleum ether by adding DBDTC 1% solution 1:3 in metal (mole) : ligand
(mole) comparison. After that, the aqueous phases were analyzed using instrument ICP-OES. La/NdDBDTC complex can be best extracted using organic solvent diethyl ether at pH 5.5 with Kd for LaDBDTC and Nd-DBDTC are 1.1870 and 0.6274. Ce-DBDTC complex can be best extracted using
solvent diethyl ether at pH 2.0 with Kd 0.9109. Instrument ICP-OES is good for standard solution
and organic phase concentration analyzing.
Keywords: Di-n-buthyldithiocarbamate, ICP-OES, REE, Solvent Extraction, Diethyl ether
introduced two computer speaker systems that use
neodymium and blend the art of sound with the beauty
of design (Fox et al., 2001).
Inductively Coupled Plasma-Optical Emission
Spectroscopy (ICP-OES) is one of several techniques
available in analytical atomic spectroscopy. ICP-OES
utilizes a plasma as the atomization and excitation
source. A plasma is an electrically neutral, highly
ionized gas that consists of ions, electrons, and atoms.
The sun, lightning, and the aurora borealis are
examples of plasmas found in nature. The energy that
maintains an analytical plasma is derived from an
electric or magnetic field; they do not “burn”
(Manning and Grow, 1997).
In the present study, extraction of La, Ce and Nd
with DBDTC as chelating extractant using organic
solvents toluene, diethyl ether and petroleum ether,
and also metals analysis using ICP-OES have been
studied.
Introduction
Rare earth elements are a series of chemical elements
of the periodic table, including the elements with
atomic numbers 57 through 71, and, named in order,
are lanthanum (La), cerium (Ce), praseodymium (Pr),
neodymium (Nd), promethium (Pm), samarium (Sm),
europium (Eu), gadolinium (Gd), terbium (Tb),
dysprosium (Dy), holmium (Ho), erbium (Er), thulium
(Tm), ytterbium (Yb), and lutetium (Lu). Yttrium (Y,
atomic no. 39) and scandium (Sc, atomic no. 21) are
sometimes included in the group of rare earth
elements. The elements cerium (Ce, atomic no. 58)
through lutetium (Lu, atomic number 71) are
commonly known as the lanthanide series (Krakew et
al., 2005).
They are essential in many and relevant
applications in chemical, metallurgical, optical,
electronic and ceramic products. In several of these
uses, the rare-earths are responsible for high
technological performances, either by participating in
the intermediate manufacturing processes or
integrating the finished products (Masson & Osvaldo,
2002). Altec Lansing Technologies, Inc., a leader in
the market for personal computer speakers, has
186
S.A. Afrillya et al.
Proceeding of The International Seminar on Chemistry 2008 (pp. 186-190)
Jatinangor, 30-31 October 2008
fungsional group. Peaks at υ 2956 cm-1 - 2775 cm-1 is
for C-H vibration from C4H9. Peak at υ 1554 cm-1 is
for C=N stretch from electron delocalization with C=S
fungsional group. Peak at υ 1462 cm-1 is from C=S
vibration bonded to nitrogen. Peak at υ 1398 cm-1 is
for CH3 symmetry vibration from C4H9. Peaks at υ
1282 cm-1-1190 cm-1 come from C-N stretch. Peaks at
υ 1130 cm-1 - 1103 cm-1 come from C=S stretch.
Peaks at υ 732 cm-1 - 524 cm-1 (finger print area)
come from C-S stretch.
Materials and Method
Materials
La2O3, CeO2 and Nd2O3 (Aldrich, 99,99%) were used
as REEs standard and diluted nitric acid was used to
dilute them. CS2, di-n-buthylamine and ammonia were
used to prepare DBDTC. Acetic acid, sodium acetic,
hydrochloride acid and kalium chloride were used to
prepared the varied buffer solutions. Toluene, diethyl
ether and petroleum ether were used as organic
solvents.
Extraction of La, Ce and Nd with DBDTC
Apparatus
Some researches of Krakew et al. (2005) and
Atanassova et al. (2006-2007) about REEs extraction
using mixtures of varied two extractants and several
organic solvents, show that uses of certain chelating
extractant and organic solvent need certain condition
for each REEs in order to be extracted with high
recovery. So, in this study, La, Ce and Nd standard
solution were prepared in varied pH.
La and Nd extraction were carried out at pH 4.0;
4.5; 5; 5.5; and 6 because light REEs were extracted
with high recovery in acidic condition. Ce extraction
was carried out at pH 2.0 and 3.5 because cerium
oxide formed its hydroxide precipitate at pH above
3.5.
DBDTC was used as chelating extractant that La,
Ce and Nd complex are extracted to organic solvents.
The mole comparison of metal and chelating
extractant was 1:3 because it can best extract the light
REEs complex. Toluene, diethyl ether and petroleum
ether were used as organic solvents to solve the
complex formed in extraction process. After
separation of the phases, the metal concentration of
aqueous phase was determined using ICP-OES.
La and Nd can be extracted with the highest
recovery at pH 5.5 using diethyl ether. Kd of LaDBDTC and Nd-DBDK at this condition are 1.1870
and 0.6274. Ce can be extracted with the highest
recovery using the same solvent at pH 2. Kd of CeDBDTC at this condition is 0.9109. Kd values of the
elements extraction are shown in figure 3, 4 and 5.
Digital pH-meter Mettler Toledo MP 220 was used
for the pH measurements, spectrophotometer UV-Vis
Ultrospec 3000 pro and spectrophotometer IR for
spectrophotometric measurements, and ICP-OES
Varian Vista MX for metal concentration analysis
spectrometrically.
Methods
DBDTC was prepared by reacting CS2, di-nbuthylamine and ammonia at 0 0C, stirred
continuously for about 30 minutes until permanent
precipitate occurred. The precipitate was separated
from the liquid and dried at room temperature.
La, Ce and Nd standard solutions were prepared
by diluting their oxide in diluted nitric. Then, the
extraction of each standard solution was carried out in
separatory funnel containing 10 mL aqueous and
organic phase. The samples were shaken for 10
minutes and stood for 10 minutes at room
temperature. After the separation of the phases, the
metal concentration in aqueous phase was determined
spectrometrically using ICP-OES.
Results and Discussion
DBDTC Characterization
DBDTC is not stored in the market, so in this study,
the chelating agent was synthesized as its ammonium
salt. This compound is melted at 42 – 46 0C, solved in
methanol and dissolved in water. Figure 1 shows the
UV-Vis spectra of DBDTC at 200-800 nm and Figure
2 shows IR spectra of ammonium-DBDTC.
The UV-Vis spectra show two peaks at 315 nm
and 357 nm, which are considered as π to π* and n to
π* transition absorption. The π to π* transition is
appeared because of C=S double bond and n to π*
transition is appeared because of lone pair electron in
S atom that absorbs light at 250-380 nm.
The IR spectra show us several peaks. Peak at υ
3450 cm-1 is for N-H stretch from ammonium
Analysis using Inductively Coupled Plasma – Optical
Emission Spectroscopy (ICP-OES)
Each atom has several energy levels. Atoms emit
electromagnetic radiation as they relax from an
excited state to their ground state. The emitted
radiation can be easily detected when it is in the
vacuum ultraviolet (VUV, 120-185 nm), ultraviolet
(UV, 185-400 nm), visible (VIS, 400-700 nm), and
near infrared regions (NIR, 700-850 nm).
187
S.A. Afrillya et al.
Proceeding of The International Seminar on Chemistry 2008 (pp. 186-190)
Jatinangor, 30-31 October 2008
4, 000
Abs
3, 000
li gan DBDTK
1
2, 000
1, 000
0, 000
20 0,0
40 0,0
Wa velength (nm)
60 0,0
80 0,0
Figure 1 UV-Vis Spectra of ammonium di-n-buthyldithiocarbamate in methanol
Figure 2 IR spectra of ammonium di-n-dibuthyldithiocarbamate
Figure 3 Kd of La-DBDTC extraction with toluene, diethyl ether and petroleum ether versus pH
Figure 4 Kd of Nd-DBDTC extraction with toluene,
diethyl ether and petroleum ether versus pH
Figure 5 Kd of Ce-DBDTC extraction with toluene,
diethyl ether and petroleum ether versus pH
188
S.A. Afrillya et al.
Proceeding of The International Seminar on Chemistry 2008 (pp. 186-190)
Jatinangor, 30-31 October 2008
Figure 6 Steps involved in the analysis of aqueous samples by ICP-OES (Manning & Grow, 1997)
because they absorb energy from plasma. Then, the
detector will detect the emission of radiation upon
relaxation from an excited state of the atoms.
Every element absorbs light in more than one wave
lengths, so we have to find the optimum wavelength to
obtain the elements’ concentration using ICP-OES.
This wavelength optimizing was done by observing
the intensities of the elements’ standard solutions at 20
various wavelengths. In this study, lanthanum oxide,
cerium oxide and neodymium oxide was used to
prepare the standard solutions with various
concentrations, 0.1, 0.2, 0.5, 1, 2, 5, 10, 20, 50, and
100 ppm. The graphic of standard solution has to be
linear in order to be able to use in the sample
concentration determination. There are several wave
lengths which give linear graphics, so we have to
choose one of the wave lengths that give the highest
intensities and less interferences for certain element.
The optimum wave lengths for La, Ce and Nd are
408.671, 401.239 and 430,357 nm.
Conclusions
La and Nd can be extracted with the highest
recovery at pH 5.5 using diethyl ether; Kd of La and
Nd at this condition are 1.1870 and 0.6274. Ce can be
extracted with the highest recovery at pH 2 using
diethyl ether; Kd of Ce at this condition is 0.9109.
ICP-OES is good for La, Ce and Nd extraction
analysis.
Acknowledgements
The authors are grateful to Laboratory Sucofindo
SBU JUM Cibitung for ICP-OES Analysis.
Coupled Plasma – Optical Emission Spectroscopy
(ICP-OES) Principles
References
The ICP-OES principles are electric and magnetic
fields, and detection of the radiation emissions by
detector. A plasma is an electrically neutral, highly
ionized gas that consists of ions, electrons, and atoms.
Argon is usually used as plasma that is used as the
atomization and excitation source (Gassing, 2005).
There are six steps involved in the analysis of
aqueous samples by ICP-OES as shown in the figure
6. Plasma temperature used is 10.000 K because at
this temperature chemical bonds of any compounds
can be broken. There are only atoms that will excite
Atanassova, M. 2006. Effect of the 18-Crown-6 and
Benzo-18-Crown-6 on the Solvent Extraction and
Separation of Lanthanoids(III) Ions with 8Hydroxyquinoline. Russian Journal of Inorganic
Chemistry. 52 (8), 1304-1311.
Atanassova, M. 2006. Solvent Extraction and
Separation of Lanthanoids with Mixture of
Chelating Extractant and 4-(2-pyridylazoresorcin. Proc. Estonian Acad. Sci. Chem. 55 (4),
202-211.
189
S.A. Afrillya et al.
Proceeding of The International Seminar on Chemistry 2008 (pp. 186-190)
Jatinangor, 30-31 October 2008
OES Variant Vista MPX. Skripsi. Universitas
Nusa Bangsa. Bogor.
Manning, T.J. & W.R. Grow. 1997. Inductively
Coupled Plasma – Atomic Emissio Spectrometry.
Springer-Verlag New York, Inc. New York.
Masson, I.O.C. & Osvaldo G.C.C. 2002. Extraction
of Heavy Rare-Earths dan Yttrium with a
Phosphonic Solvent. Contribuição Técnica aos
Anais da Associação Brasileira de Química,
51(1),1-8.
Kraikaew, J., Wanne S. & Chavlek C. 2005.
Solvent Extraction Study of Rare Earth from
Nitrate Medium by the Mixture of TBP and
D2EHPA in Kerosene. Chemistry and Material
Science
Research
Program.
Bangkok.
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