Book reviews

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Solid-phase Extraction

Edited by Nigel J. K. Simpson. Pp. 528. Marcel Dekker. 2000. Price: £124.00 (Hardcover). ISBN: 082470021X

Solid-phase extraction (SPE) has about a 20 year history of use in analytical laboratories. According to the book’s editor, a Chemical Abstracts search of 1995 literature revealed about 180 citations with the term ‘solid-phase extraction’ in the title. The annual number is now likely to be considerably greater, and articles that use SPE, but do not cite it specifically as a keyword, will be much greater again. Considerations of simplicity, reproducibility, reliability and automation capabilities should ensure that SPE sample preparation tools will be popular and permanent features of many laboratories. Once adopted as an established procedure, it is difficult to see many new alternatives coming onto the horizon.

The SPE approach has replaced conventional (normally solvent extraction) methods in the routine laboratory. This book will therefore be targeted at those users who have practical needs to isolate an analyte, class of analyte, or multi-residue components from samples, or seek an experimental design approach to implement the method. SPE relates chemical principles of sample and sorbent phases and so it is necessary to appreciate the subtleties of chemical interactions in order to effectively implement an SPE method. In this book there should be sufficient information to design an approach, with suitable validation guidelines, to develop a successful method. The 16 chapters of basic information (Chapter 17 is a commentary on possible future developments) cover topics from theory, principles and practice, to sorbent chemistry, consideration of matrix effects, interactions and mixed-mode behaviour, automation, immuno-affinity extraction, matrix solid-phase extraction, integration into the analytical technique, and a range of selected applications. The latter describes, suitably in-depth, the use of SPE in veterinary, pharmaceutical, biological and environmental areas (i.e., the major SPE applications areas) to provide the reader with a systematic understanding of SPE methodology. The environmental area could be further supplemented with detailed case-studies, with figures and tables demonstrating specific results, but this is a minor comment.

Given the catchwords of the title, it is perhaps surprising to this reviewer that solid-phase micro-extraction (SPME) has not been given more attention. Being mentioned only in passing, and with a few pages on SPME by Poole and Poole, this very topical method would easily be justified in such a book, and possibly extend the book’s marketability. Perhaps this was a conscious decision by the editor not to extend the extraction focus beyond strictly that of SPE.

In summary, this book will be of value as a laboratory reference for those users who either are using SPE, or are using conventional extraction methods with a goal of adopting SPE methodology, and require a more thorough understanding of the role of SPE.

Philip Marriott

RMIT University, Melbourne, Australia

Methods for Trace Environmental Trace Analysis

By J. R. Dean. Pp. 284. John Wiley and Sons Ltd. 2003. Price: £29.95 (Paperback). ISBN: 0470844221

More and more the environment is exposed to anthropogenic pollution caused by the release of toxic compounds to air, water, soil and sediment, which can cause acute or chronic effects towards living organisms. In environmental sciences, it is pivotal to determine and identify those organic and inorganic compounds responsible for decreasing the quality of the overall environment. To fulfil such a need, John R. Dean offers the book entitled “Methods for Environmental Trace Analysis”, oriented towards the description of techniques and protocols for the determination of both organic and inorganic species in a wide range of environmental matrices. The book is recommended to all specialists, from students to researchers and teachers, who want to update their knowledge on instrumental analytical tools applied to environmental chemistry. The book is characterized by a very structured index, easy to follow and logically distributed, which includes the learning objectives to be achieved, supported by case studies and a series of well selected problems allocated to each chapter. To fully understand each analytical principle, the fundamentals of most significant techniques are clearly described, thus providing a deep insight into the basic principles.

Twelve chapters concisely describe the methodological steps that have to be followed from sampling to final reporting of the results. Two chapters are of practical importance: chapter 3 on “Sampling” and chapter 4 “Storage of Samples”. Those items are often forgotten by the environmental chemist despite the fact that the sampling and storage methodologies will reflect the quality of final results.

The body of the book is divided into two main parts: analysis of inorganic compounds and analysis of organic compounds. For each group, it comprises both the determination of solid and of liquid samples.

Chapters 5 and 6 are devoted to the analysis of inorganic compounds in solid samples (sediments and foodstuff) and water (natural and wastewater), respectively, with the objectives of learning sample preparation, decomposition of the matrix and extraction. Chemical speciation studies are highlighted, especially in relation to the analysis of methylmercury, tin, arsenic and chromium. In the case of liquid samples, where sample preconcentration is needed to enable the detection of inorganic species, techniques such as liquid–liquid extraction, ion-exchange and co-precipitation are discussed, indicating the applicability of each.

Chapters 7–11 refer to the analysis of organic compounds and include semivolatile organic compounds such as phenols, pesticides, polycyclic aromatic hydrocarbons, surfactants and volatile organic compounds (BTEX). Sample preparation, extraction and analysis are included. As regards solid samples (Chapter 7), the author has been able to nicely introduce conventional techniques such as Soxhlet extraction, ultrasonic extraction and supercritical fluid extraction, and novel techniques, starting with microwave extraction for organic compounds to pressurized fluid extraction and matrix solid-phase dispersion. Extraction of liquid samples has not undergone any remarkable changes in the last years and the author indicates the three most widely used techniques: liquid–liquid extraction for the determination of dissolved and particulate fraction of the sample; solid phase extraction with several formats (cartridges, disks, etc.) and sorbents (normal or reverse phase); and finally solid phase microextraction. Volatile compounds are treated in a separate chapter because of the fact that due to the high Henry’s constant, the instrumentation needed for their analysis involves purging the target compounds from water/air directly into an adsorbent which is thereafter thermally desorbed, so that losses due to volatilization are minimized. Chapter 11 is fully devoted to instrumental analysis. It covers gas and liquid chromatography, infrared spectroscopy, flame atomic absorption spectroscopy, inductively coupled plasma atomic emission spectroscopy, anodic stripping voltammetry, etc., with the objective of understanding the principles of each technique to identify instrumental requirements, to evaluate the differences among them, to know their usability, etc.

Finally, Chapter 12 “Recording of Information in the Laboratory and Selected Resources” is of paramount importance nowadays since laboratories need to follow quality and control charts to record scientific information and analytical details of each sample.

Overall, the book describes, in a concise, pedagogical way, both traditional and emerging techniques for environmental analysis and discusses the advantages and disadvantages of each. As highlighted by John R. Dean, the advent of techniques such as pressurized liquid extraction or SPME represents a step forward in environmental chemistry in the sense that sample preparation is minimized and the quality of the results enhanced. Each section is accompanied by specific protocols which can be directly applied in any laboratory and figures and tables of excellent quality. In short, after reading the book it is assured that the principles of the different analytical techniques introduced can be satisfactorily understood and one will be able to carry out specific methodologies for trace analysis of organic and inorganic compounds in environmental matrices.

Silvia Lacorte

Scientific Researcher Department of Environmental Chemistry, IIQAB-CSIC, Jordi Girona 18–26, 08034 Barcelona, Catalonia, Spain. E- mail: slbqam@cid.csic.es

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