Lanthanides Series Determination by Various Analytical Methods

440 Pages·2016·18.226 MB·English

by  Mohammad Reza Ganjali, Vinod Kumar Gupta, Farnoush Faridbod, Parviz Norouzi

LANTHANIDES SERIES
DETERMINATION BY
VARIOUS ANALYTICAL
METHODS
MohaMMad Reza Ganjali
Center of Excellence in Electrochemistry
University of Tehran, Tehran, Iran
Vinod KuMaR Gupta
Department of Chemistry
Indian Institute of Technology Roorkee, Roorkee, India;
Department of Applied Chemistry
University of Johannesburg, Johannesburg, South Africa
FaRnoush FaRidbod
Center of Excellence in Electrochemistry
University of Tehran, Tehran, Iran
paRViz noRouzi
Center of Excellence in Electrochemistry
University of Tehran, Tehran, Iran
AMSTERDAM • BOSTON • HEIDELBERG • LONDON • NEW YORK • OXFORD
PARIS • SAN DIEGO • SAN FRANCISCO • SINGAPORE • SYDNEY • TOKYO
Copyright
Elsevier
Radarweg 29, PO Box 211, 1000 AE Amsterdam, Netherlands
The Boulevard, Langford Lane, Kidlington, Oxford OX5 1GB, UK
50 Hampshire Street, 5th Floor, Cambridge, MA 02139, USA
Copyright © 2016 Elsevier Inc. All rights reserved.
No part of this publication may be reproduced or transmitted in any form or by any means,
electronic or mechanical, including photocopying, recording, or any information storage and
retrieval system, without permission in writing from the publisher. Details on how to seek
permission, further information about the Publisher’s permissions policies and our arrange-
ments with organizations such as the Copyright Clearance Center and the Copyright Licens-
ing Agency, can be found at our website: www.elsevier.com/permissions.
This book and the individual contributions contained in it are protected under copyright by
the Publisher (other than as may be noted herein).
Notices
Knowledge and best practice in this field are constantly changing. As new research and ex-
perience broaden our understanding, changes in research methods, professional practices, or
medical treatment may become necessary.
Practitioners and researchers must always rely on their own experience and knowledge
in evaluating and using any information, methods, compounds, or experiments described
herein. In using such information or methods they should be mindful of their own safety
and the safety of others, including parties for whom they have a professional responsibility.
To the fullest extent of the law, neither the Publisher nor the authors, contributors, or edi-
tors, assume any liability for any injury and/or damage to persons or property as a matter
of products liability, negligence or otherwise, or from any use or operation of any methods,
products, instructions, or ideas contained in the material herein.
British Library Cataloguing-in-Publication Data
A catalogue record for this book is available from the British Library
Library of Congress Cataloging-in-Publication Data
A catalog record for this book is available from the Library of Congress
ISBN: 978-0-12-804704-0
For information on all Elsevier publications
visit our website at http://store.elsevier.com/
Typeset by Thomson Digital
Preface
Lanthanides, or as suggested by IUPAC, lanthanoids, are f-block ele-
ments that are also referred to as rare earths, due to their scarcity in the
earth’s crust. Lanthanides, the discovery of which mainly dates back to
the 18th century, were found comparatively later than many other chem-
ical elements mostly due to the similarity of the characteristics of their
naturally occurring compounds that are mainly oxides, the semblance of
their physico-chemical features, unavailability of expedient purification,
separation, and detection means, and above all, lack of awareness of their
number and nature.
The expansion of human knowledge and the expansion of informa-
tion on the chemistry of these elements have gradually increased the ap-
pearance of these elements in various aspects of human life, ranging from
chemical and automotive industries to glass and ceramics, optics, elec-
tronics, and agriculture. Although lanthanides are customarily considered
as being rather similar in nature, their applications, very much, dependent
on certain peculiar properties of each element and its compounds, which
arise from differences in the arrangements of their f-block electrons. The
similarities in the properties of these elements, with those of main ele-
ments present in the biological systems like calcium, have increased the
role and significance of lanthanides in pharmaceutical industry and medi-
cine, and these elements and their compounds are currently the focus of
various biological research.
Consequently, the increased applications of these elements have inten-
sified the environmental concerns about them, leading to amplified inter-
est in research on the biology of rare earths. These developments have
intensified the need for techniques and procedures that are applicable to
the analysis of lanthanides, and hence, a range of complex as well as sim-
ple and fast methods have been developed to this end.
Although there exists a number of books on the nature and applications
of these elements, the need for a comprehensive text, further covering de-
tails on their analysis and quantification, has been felt for a long time. In
this accord and in the light of our long years of experience on the analysis
of lanthanides, we decided to strike a blow in filling in this gap through
compiling a rather comprehensive book covering the history, chemistry,
and varied techniques applied to the analysis of lanthanides in geological,
industrial, agricultural, environmental, biological, and food samples.
ix
x Preface
The result of this endeavor, Lanthanides Series Determination by Various
Analytical Methods, tends to cover the diverse spectroscopic and electro-
chemical procedures developed and used for the analysis of rare earths.
The text begins with a synopsis on the nature of the elements, and then
provides an extensive review on the varied properties and applications of
lanthanides in the context of chemical, agricultural, environmental, clini-
cal, and pharmaceutical industries and biological research. And then, the
text provides a brief description on the methods of determination used in
the analysis of real samples, the principles of their instrumentation, and
their application, accompanied by a wealth of experimental examples on
the analysis of various samples.
Based on its content, the present text can be useful for researchers and
academics, as well as those active in different areas of industry. Graduate
and undergraduate students interested in the analysis of lanthanides can
also find this book useful. The authors hope that this work can meet the
endless need among the researchers in various areas of science and tech-
nology.
In the end, I would like to appreciate all the sincere efforts invested
into this project by Professor Vinod K. Gupta from the Indian Institute of
Technology Roorkee (India), Professor Parviz Norouzi and Dr Farnoush
Faridbod from the University of Tehran (Iran), and Dr Morteza Rezapour
from the Research Institute of Petroleum Industry (Iran), without whose
constructive work and heartwarming comments this work could not have
been composed.
Mohammad Reza Ganjali
Professor in Analytical Chemistry,
University of Tehran, Tehran, Iran
2016
C H A P T E R
1
Introduction to Lanthanide
Series (From Lanthanum
to Lutetium)
O U T L I N E
Chemical Properties of Lanthanides 6
Lanthanum 9
Cerium 11
Praseodymium 13
Neodymium 14
Promethium 16
Samarium 17
Europium 20
Gadolinium 22
Terbium 24
Dysprosium 25
Holmium 26
Erbium 27
Thulium 28
Ytterbium 29
Lutetium 30
References 31
Lanthanides Series Determination by Various Analytical Methods. http://dx.doi.org/10.1016/B978-0-12-804704-0.00001-3
Copyright © 2016 Elsevier Inc. All rights reserved.
1
2 1. INTrOdUcTION TO LaNThaNIdE SErIES (FrOm LaNThaNUm TO LUTETIUm)
A quick look at the structure of the periodic table of elements (Fig. 1.1)
usually draws one’s attention toward the two rows of boxes containing
elements with rather unfamiliar names, conventionally placed under the
main body of the table. The elements in the first row (i.e., elements 57 to
71), which we shall focus on here, are named “lanthanides,” after the first
element in the row, that is, lanthanum, which is the 57th element in the
table.
These elements possess unique photogenic, magnetic, mechanical, and
nuclear properties and have found widespread applications in glass and ce-
ramic manufacturing, metallurgy, electronics, and agricultural industries.
The name lanthanum originates from the Greek word laνuaνw
[lanthanō], which literally means to lie hidden. The International Union of
Pure and Applied Chemistry (IUPAC) has accepted the collective names
lanthanides or lanthanoids for these elements, and in the light of the fact
that the term lanthanoids means similar to lanthanum (while the element
lanthanum is a member of the group, the first name, i.e., lanthanides, has
become more common). A point to be considered is that the suffix “-ide” is
used for making the names of several anions (i.e., sulfide, bromide, etc.) in
chemistry, which might lead to misconceptions about the nature of these
elements. However, the application of the term has become commonplace
in the chemical literature [1].
The history of lanthanides initiated with Lieutenant Carl Axel Arrhe-
nius in 1787, who although an artillery officer at the time, remained an
amateur geologist. As he was studying a mine located near the town Yt-
terby in Switzerland, he came across a blackish, very dense mineral that he
decided to entitle Ytterbite. Initially, he suspected that Ytterbite contained
tungsten, which was a newly discovered element at the time. But the later
FIGURE 1.1 The lanthanide series in the periodic table.
INTrOdUcTION TO LaNThaNIdE SErIES (FrOm LaNThaNUm TO LUTETIUm) 3
FIGURE 1.2 Abundance of lanthanides in the earth’s crust.
studies by the Finnish chemist Johan Gadolin in 1794, using conventional
wet chemistry techniques, showed that the mineral was composed of the
oxides of beryllium, iron, silicon, and something unidentified. This un-
identified “element” was named “yttria” by Gadolin. Further scrutiny in
the 19th century showed that this new “element” was actually a mixture
of the oxides of six other elements. During this work, pure dysprosium
(Dy) and thulium (Tm) were obtained after 58 and 11,000 recrystalliza-
tions steps, respectively. The last of the naturally occurring elements was
lutetium (Lu), which was discovered in 1907, but the last member of the
lanthanide series (i.e., element number 61, named promethium), which is
a synthetic element, was characterized in 1947 [2].
A classification of the lanthanides (Ln) is based on dividing the ele-
ments into the so-called light (i.e., La, Ce, Pr, Nd, Pm, and Sm) and heavy
Lns (i.e., Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu), the former group being
more abundant (Fig. 1.2).
Lanthanides are sometimes considered to behave as group 3 elements
because of the formation of trivalent cations. An interesting fact is that
the elements are not as rare as their names might imply. Lanthanides are
naturally found in some minerals, including but not limited to xenotime,
monazite, and bastnaesite.
Xenotime and monazite are orthophosphate (LnPO) salts of the ele-
4
ments. The mineral monazite further contains yttrium and the radioac-
tive thorium, making it difficult and dangerous to deal with. Bastnaesite
is a mixed fluoride carbonate mineral (LnCO F) (Table 1.1). As a rule of
3
thumb, one can say that lanthanides with even atomic numbers are more
common than those with odd ones, and the abundance of the most com-
mon ones decreases from Ce to La, Nd, and Pr.
4 1. INTrOdUcTION TO LaNThaNIdE SErIES (FrOm LaNThaNUm TO LUTETIUm)
TABLE 1.1 common minerals containing Lanthanides [3]
Mineral Formula
Aeschynite (Ln,Ca,Fe,Th)(Ti,Nb)(O,OH)
2 6
Allanite (orthite) (Ca,Ln)(Al,Fe)(SiO)(OH)
2 3 43
Anatase TiO
2
Ancylite SrLn(CO)(OH)•HO
32 2
Apatite Ca(PO)(F,Cl,OH)
5 43
Bastnaesite LnCOF
3
Brannerite (U,Ca,Ln)(Ti,Fe)O
2 6
Britholite (Ln,Ca)(SiO,PO)(OH,F)
5 4 43
Cerianite (Ce,Th)O
2
Cheralite (Ln,Ca,Th)(P,Si)O
4
Churchite YPO•2HO
4 2
Eudialyte Na Ca(Fe,Mn)Zr(Si,Nb)Si O (OH,Cl,HO)
15 6 3 3 25 73 2 5
Euxenite (Ln,Ca,U,Th)(Nb,Ta,Ti)O
2 6
Fergusonite Ln(Nb,Ti)O
4
Florencite LnAl(PO)(OH)
3 42 6
Gadolinite LnFeBeSiO
2 2 10
Huanghoite BaLn(CO)F
32
Hydroxylbastnaesite LnCO(OH,F)
3
Kainosite Ca(Y,Ln)SiO CO•HO
2 2 4 12 3 2
Loparite (Ln,Na,Ca)(Ti,Nb)O
3
Monazite (Ln,Th)PO
4
Mosandrite (Ca,Na,Ln) (Ti,Zr)2SiO HF
12 7 31 6 4
Parisite CaLn(CO)F
2 33 2
Samarskite (Ln,U,Fe)(Nb,Ta,Ti)O
3 5 16
Synchisite CaLn(CO)F
32
Thalenite YSiO (OH)
3 3 10
Xenotime YPO
4
Yttrotantalite (Y,U,Fe)(Ta,Nb)O
4
INTrOdUcTION TO LaNThaNIdE SErIES (FrOm LaNThaNUm TO LUTETIUm) 5
It is noteworthy that although the isolation of pure lanthanides is rath-
er cumbersome, fortunately it is not required for many applications. The
conventional separation routines are based on the extraction of the ele-
ments from the ores using sulfuric and hydrochloric acids and/or sodium
hydroxide, whereas the modern routines are conducted through selec-
tive complexation, solvent extractions, and ion exchange techniques. The
main source of the ores is China, with almost 43% of the global deposit,
whereas India, Kazakhstan, Kyrgyzstan, Malaysia, Russia, Thailand, and
the United States also have deposits of these elements [3].
The terms rare earths (REs), rare earth elements (REEs), or rare earth
metals (REMs) are also used to refer to lanthanides in addition to scan-
dium (Sc) and yttrium (Y), which have a range of strategic applications
including medical and energy technologies, lasers, batteries, magnets,
magnetic resonance imaging (MRI) contrast agents, catalysts, and alloys.
The estimates of worldwide rare earth reserves for different countries are
illustrated in Fig. 1.3.
The US Geological Survey estimated the total rare earth reserves world-
wide to be about 130 million metric tons (mmt), most of which is depos-
ited in China, which is also the biggest commercial supplier of rare earths.
Brazil also owns almost 22 mmt of these reserves, and other countries with
considerable reserves of rare earths include Australia, India, USA, and
Malaysia. The lanthanides, cerium, lanthanum, and neodymium, are the
FIGURE 1.3 The global rare earth reserves as estimated as of 2014, by country.
6 1. INTrOdUcTION TO LaNThaNIdE SErIES (FrOm LaNThaNUm TO LUTETIUm)
TABLE 1.2 Price of Some metallic Lanthanides [5]
Metal Purity $/kg
La Min. 99% 9.6
Ce Min. 99% 10
Pr Min. 99% 150
Nd Min. 99% 83
Sm Min. 99% 25
Eu Min. 99% 1000
Gd Min. 99% 132.5
Tb Min. 99% 825
Dy Min. 99% 477
most highly produced rare earth elements [4]. Information on the prices of
metallic lanthanides are also provided in Table 1.2.
CHEMICAL PROPERTIES OF LANTHANIDES
In fact, Lns are silvery and shiny when cut, but they tarnish quickly in
air. These elements react slowly with cold water, and heating or decreas-
ing the pH increases the reaction rate considerably. These f-block elements
share many characteristics, including similar physical properties, with 3+
as the most common oxidation state, in addition to the less common states
of 2+ and 4 +. Formation of crystalline structures with coordination num-
bers greater than 6 (usually 8–9), which tends to decrease across the series;
minor crystal-field effects; a preference for reacting with the most electro-
negative elements such as oxygen (the reaction with oxygen is slow at the
ambient temperature, but the elements ignite if heated up to 150–200°C),
or halogens (upon heating) and S, H, C, and N upon heating. This similar-
ity is the reason why lutetium, which is a d-block element, is considered
a lanthanide [6,7].
The electron configurations of lanthanides (Table 1.3) were experi-
mentally determined through the study of the lines in their emission
spectra, which basically indicate the energy change for electron transfer
between energy levels. A look at the electron configuration of these ele-
ments simply shows the reason behind the similarity of the properties
of these elements to be due to the fact that in the majority of cases, the
fifth and sixth energy levels of the elements contain identical numbers
of electrons.