Problem solving—continued instrumentation techniques

ICP-OES continues to dominate the market because of its ease of use and relatively low maintenance cost. Inductively coupled plasma mass spectrometry (ICP-MS) is a very powerful state-of-the-art technique used for metal analysis of all kinds of samples but requires highly skilled operators. A vast amount of information is received that is not necessarily required as part of problem-solving or routine support. The cost difference and relative freedom from maintenance problems would favour ICP-OES. This book is aimed at practitioners requiring multi-elemental analysis in industrial, environmental, pharmaceutical and research laboratories, where information on identification and quantification is required on a regular basis. The main focus of this book will be on sample preparation, a topic overlooked in most books on atomic spectroscopy. It is aimed at most ICP-OES and ICP-MS users to show that the instrument is useless unless the sample is prepared in a suitable state that can be used to accurately and precisely quantify the metals present. 

Volume 37 of Metkods of Biochemical Analysis focuses on the application of special instrumental techniques to problems in biology. Focusing selected volumes of this series on instrumentation is particularly appropriate because advances in instrumentation often times provide new vistas in science. The development of the pH meter, spectrophotometer, radioactivity and the associated measuring devices early in this century had a significant impact on research in many areas of biology and biochemistry. Likewise the instrumentation reviewed in this volume have and will continue to have a significant affect on the rate in which we solve problems. 

The analytical needs of the petroleum industry continue to drive the ever-increasing selectivity and sensitivity of GG-MS instrumentation and provide analysts in other industries with new analytical techniques that they may apply as their samples become more complex. New innovations in GC-MS to gain ever greater speed and resolution in GG and MS, such as fast GC-MS, GC-GC-MS, and GC-TOF-MS, will open new avenues of analysis and problem solving for tomorrow s upstream and downstream analysts. 

For various reasons, reliable electronic-nose applications have been slower to develop. Chapter 13 discusses the benefits of MS as a potential e-nose sensor. This book also discusses the value of time-of-flight MS to the study of flavors and odors. Incorporating the human sense of smell with potent analytical systems is invaluable in problem solving. Just as sample preparation procedures and analytical instrumentation have continued to evolve and improve, so have olfactometry techniques. Chapters 11 and 12 cover various olfactometry techniques, including a new, easier-to-implement method called SNIP. 

The on-line hyphenation of CEC and MS has several potentially challenging instrumental aspects which complicate the successful combination of these two techniques. The first arises due to the absence of a CEC column outlet electrolyte reservoir and the need to achieve electrical continuity for the CEC system, and, in the case of ESI, also for the ESI ion source. Another consideration is the requirement to efficiently remove the mobile phase and simultaneously generate gas phase ions from the analyte, which have to be transferred with high efficiency into the vacuum of the mass analyzer. Because of this situation, numerous designs have been advanced which solve to various degrees these related problems and are discussed individually below. 

What, however, is particularly interesting is the views expressed at the conference about quantum chemistry and the ways it envisaged to influence the development of other branches of chemistry. It was noted that many chemists "use tools provided by quantum chemistry" (National Academy of Sciences 1971, 2). Furthermore, the needs in computer time and facilities were continuously on the increase among the quantum chemists and users of quantum chemical techniques and, hence, (quantum) chemists could not meet "their needs... to develop quantum chemistry further as a powerful tool in the service of chemistry and society" (National Academy of Sciences 1971, 3). It was also stressed that the computational techniques of quantum chemistry and theoretical chemistry, in general, should be regarded as an "instrument for solving chemical problems, and hence as an adjunct to other instrumentation" (National Academy of Sciences 1971, 13). 

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