вход по аккаунту


Book Review Activation Analysis with Charged Particles. Ellis Horwood Series in Analytical Chemistry. By C. Vandecasteele

код для вставкиСкачать
stereochemistry or conformation are therefore excluded
completely from the discussion. In accordance with this,
methods for measuring such structure-related N M R
parameters as coupling constants or cross-relaxation rates
are not included.
The organization of the book falls clearly into seven chapters. In the introductory chapter the principles of 2D N M R
spectroscopy are briefly described, and practical information
and advice is given on the processing of the data, presentation of the spectra and planning of experiments (including
pulse width calibration). Chapter 2 is devoted to H-H connectivities, and includes a detailed description of the basic
COSY experiment and six variants of it. The chapter concludes with an account of multiple quantum N M R spectroscopy. In Chapter 3 methods for determining H-C connectivities are described. A full account of all the methods. from
the first selective SPT experiments through to the most sensitive present-day pulse sequences with ‘H detection, is given.
Chapter 4 is devoted to relayed experiments, including
homo- and heteronuclear, single and multiple relayed experiments, and the related TOCSY experiment. Chapter 5 then
deals with l3C-I3Cconnectivities, with a strong emphasis on
the INADEQUATE experiment. The latest variants with ‘H
detection are also treated. Finally, Chapter 6 presents spectroscopic problems of structure determination in organic
molecules, and solutions to these are provided in Chapter 7.
The main emphasis of the book is on the fifty or so pulse
sequences that are described. The discussion of these is supported by an excellent survey of the literature, with a comprehensive bibliography which covers not only the first publication on each pulse sequence and the modifications
subsequently introduced, but also many published applications. The authors give details of experimental conditions
which they have themselves tested and found to give good
results, and the majority of the spectra shown are their own.
In many of the examples spectra recorded on the same compound using different methods are shown and discussed in
order to compare the information given by each method.
This gives the user a valuable impression of the advantages
and disadvantages of the various methods. The descriptions
of the pulse sequences include explicit information on phase
cycles, although regrettably these are incorrect in some cases.
Readers must therefore be warned against using these pulse
sequences uncritically; instead they should compare them
with the original papers.
The book does not aim to give a rigorous theoretical understanding of the pulse sequences, and the reader who is
unfamiliar with “spin gymnastics” will experience some difficulty in understanding the discussions. Inevitably, therefore, certain expressions are used, such as “passive transfer”,
without their meaning being fully explained.
The numerous figures illustrating the techniques described
are an important feature of the book. However, it is incomprehensible why the labeling of the spectra is so sparse and
frequently illegible, often making the search for the spectral
details discussed in the text a laborious task. The poor quality and often inadequately small scale of the figures is especially annoying in Chapters 6 and 7 which contain the spectroscopic problems. Also cross peaks are sometimes missing,
so that one is forced to read the solution to the problem.
In summary it can be said that this book offers a detailed,
excellently researched and unbiased account of 2D N M R
methods for determining molecular constitution. For the
N M R practitioner it provides very useful information and
advice on planning experiments and interpreting spectra, illustrated by interesting examples from natural products
chemistry. One is willing to forgive the less than perfect
c) VCH Verlagsgesellschafr mhH. 0-6940 Weinherm, I989
quality of the figures and the errors that are probably unavoidable in view of the large amount of material included.
Christian Criesinger [NB 965 I E ]
Laboratorium fur Physikalische Chemie
der Eidgenossischen Technischen Hochschule
Zurich (Switzerland)
Activation Analysis with Charged Particles. Ellis Horwood
Series in Analytical Chemistry. By C. Vundecasteele. Ellis
Horwood, Chichester/Halsted Press, New York 1988.
171 pp., hard cover, $29.95. -ISBN 0-7458-0175-7/
0-470-21 204-7
In contrast to neutron activation analysis (NAA), charged
particle activation analysis (CPAA), mainly using protons,
but also deuterons, tritons, and nuclei of helium-3 and helium-4, has found little use up to now in elemental trace analysis; consequently it has no chance of becoming a universal
routine method. Nevertheless CPAA, which has very high
sensitivity, can be used as a complementary method with
NAA and other trace analysis methods in special types of
problems. It offers higher sensitivity than the other methods,
and also eliminates ambiguity in some cases, for determining
light elements such as H, Be, B, C, N and 0 down to ppb
concentrations, especially in ultra-pure metals and semiconductors. However, the acceleration of the particles for CPAA
requires very expensive equipment such as a Van de Grdaf
generator or a cyclotron (for protons and deuterons with
energies of 2 to 20 MeV), and sometimes causes complex
nuclear reactions which necessitate subsequent radiochemical separation. Consequently it has great disadvantages
compared with NAA and atomic spectroscopy for determining medium and heavy elements, e.g. in geochemical o r biological matrices, and only in rare cases is it sensible to use it
for such analyses.
The author of this first monograph on the theory, experimental requirements and applications of CPAA, who has
considerable practical experience in this field, is well aware
of the limitations of the method. About a half of the book is
taken up by general matters, including introductions to the
theoretical basis, descriptions of accelerators and irradiation
techniques, the relevant nuclear reactions and data on these,
and the procedures needed for calibration and avoidance of
errors. In the chapters that follow describing applications to
trace analysis, the practical importance of CPAA in each of
the areas covered is clearly reflected by the numbers of publications cited. The most important chapter, “Determination
of Light Elements”, has 85 references. That on “Determination of Medium and Heavy Elements in Metals and Semiconductors”- where irradiation by protons is still the most
important experimental method - has 42 references. “Analysis of Geological, Environmental and Biological Samples”
has 14 references, as does the more academic “Activation
Analysis using Heavy Ions”. In all the chapters the literature
up to the present date is covered very thoroughly and described in clear language, thus giving students, teachers and
those interested in using the method an excellent picture of
the capabilities of CPAA, although only a few experts will
ever be able to use the method in their own laboratories. The
main value of the book therefore lies in the information on
when it is appropriate to use CPAA, and where to turn for
help in such cases.
Giinther Tolg [NB 975 IE]
Institut fur Spektrochemie
Dortmund (FRG)
0570-0833jSSjOR0R-l072 $02.50/0
Angew. Chem. In[. Ed. Engl. 28 (1989) N o . 8
Без категории
Размер файла
157 Кб
chemistry, analytical, horwood, vandecasteele, book, series, activation, ellis, analysis, review, particles, charge
Пожаловаться на содержимое документа