- Email: [email protected]
Mass spectrometry in the biological sciences
XII
The single term of nuclear magnetic resonance in fact covers a wide range of conceptually very different methods including NMR spectroscopy, time-domain NMR and NMR imaging. Similarly, NMR finds applications not only in chemistry but also in physics, medicine, industrial quality control, and even in petroleum prospecting. Reflecting this, the other 7 volumes cover 5 main aspects of Nuclear Magnetic Resonance: Inorganic applications; polymers and liquid crystals, quadrupolar nuclei; one- and multi-dimensional solution spectroscopy; applications; solid Physics methods; solid-state applications; Biological applications; Instrumentation; organic applications; relaxation topics; theory; Biomedical applications; imaging principles and applications. Each of these major sections is divided into subsections containing related topics which in turn group together several articles. There are over 500 articles, written by internationallyrecognized authoritiesin each field and containing numerous high qualitycolour or black & white photos, drawings and spectra. The articles are extensively cross-referenced and indexed while the reference listsare very complete and up to date. As an example of the structure and, more importantly, the completeness of this Encyclopedia, the subsections and topics of Section 4 are: 4.1 Relaxation Times 4.1.1 Experimental 4.1.2 Theory 4.2 Instrumentation 4.3 Chemical Shifts 4.3.1 Experimental 4.3.2 Theory 4.4 Organic Applications 4.5 Data Processing 4.6 Spin Coupling 4.7 Solvent Studies 4.8 Carbon-13 Studies 4.9 Field Gradient Experiments containing a total of 67 articles. As is clear from these titles, the Encyclopedia covers nearly all aspects of NMR technology, applicaAn initially theory. tions and disconcerting, but finally pleasing aspect of this Encyclopaedia is that the individual articles within any given topic are in fact distributed througl
l
l
l
l
trends in analytical chemistr): vol. 76, no. 7, 1997
hout the 7 volumes in alphabetical order. This means that if you wish to consult all the papers thematically grouped together in ‘4.5 Data Processing”you need to consult Volume 2 for “Computer Assisted Structure Elucidation”, Volume 3 for ‘Data Processing”, ‘Fourier Transform &Linear Prediction Methods”, “Fourier Transform Spectroscopy” and Volume 5 for “Maximum Entropy Reconstruction”. On the other hand, it can be quite fruitful for stochastic information acquisition; ‘Data Processing” being preceded by “Cross Polarization in Solids” and “Cryogenic Magnets for Whole Body Magnetic Resonance Systems”, and followed by ‘Decoupling Methods” and ‘Degenerative Disk Disease Studied by MRI”. It should be pointed out however that usually article titles are chosen in such a way that related subjects are grouped together. Diffusion for example is treated in 7 articles : ‘Diffusion: Clinical Utility of MRI Studies”, ‘Diffusion & Flow in Fluids”, ‘Diffusion Measurements by Magnetic Field Gradient Methods”, ‘Dif-
Mass spectrometry
fusion & Perfusion in MRI”, ‘Diffusion in Porous Media”, ‘Diffusion in Rare Gas Solids” and ‘Diffusion in Solids”, with a total of 451 references. I can make only two suggestions to the Editors for an eventual Supplementary Volume : include an article on industrial applications of Time-Domain (i.e “Low Resolution” or “Wideline’? NMR and an article grouping together all the different types of pulse sequences used in hoheteronuclear, ID-, monuclear, multi-D spectroscopy, imaging and relaxation experiments. This “Encyclopedia of Nuclear Magnetic Resonance” is an essential reference work for anyone using NMR in industry, research or medicine. It should be very useful for those wanting to have information about the theory, the applications and the history of NMR. DOUGLAS
N. RUTLEDGE
DI: D.N. RutledgeLaboratoire de Chimie Analytique, Institut National Agmnomique, 16 rue Claude Bernard 75005 Pan’s, Fence.
in the biological sciences
Mass S;c3ectrometryin the Biological Sciences, edited by A. L. Burlingame and S. A. Car< Humana Press, Totawa, NJ, 1996, xii + 570 pages, $145.00, ISBN 0-89603-3406/96 This symposium volume gathers 26 contributions from a 1994 symposium of the same name. The 1994 meetings was a continuation of the previous meetings on the same subject, proceedings of which are also available. There is a continuing organizingcommittee that organizes and collects the funds for these meetings - the cochairs for the 1994 meeting are the current volume’s editors. Clearly there is a healthy interchange of ideas in these conferences. As might be expected, the emphasis is on applications. A few contributions are more basic and more technique-oriented, such as those emphasizing time-offlight mass spectrometry (Cotter) or Fourier transform ion cyclotron res-
onance instruments (Smith). Other fundamental contributions include those of electrospray ionization (Aplin), matrix-assisted laser desorption ionization (Nelson), MS/MS (Mann), or methods for handling small amounts of sample (Roeraade). Even these contributions are sprinkled liberally with applications in biochemical analysis. Clearly, the mass spectrometry that supports analyses in this area has to be somewhere, developed and by somebody. But it is perhaps best to view this book as the latest volume in a continuous series that chronicles the USE of mass spectrometry in the biological sciences. Development of the science of mass spectrometry still needs to be chronicled elsewhere. The question then becomes how well each volume defines and documents the uses. The technology that underlies the tremendous advances in the field of biological mass spectrometry continues to change very rapidly. A
XIII
trends in analytical chemistry, vol. 16, no. 7, 1997
year represents a long time. A year sees shifts in the scope of problems attempted, and the availability of commercial instruments to adopt as tools in their solution. This 1996 tome documents a 1994 symposium, and the dated nature of the work is too readily apparent. The chapters contain references to the original literature through 1994, and in a few instances, to the first part of 1995 as the final galley proofs were corrected. Even in an age of instant printing and rapid dissemination of information, publication takes time. As a consequence, this volume does not fully represent today’s capabilities in biological mass spectrometry. But as the editors point out in their preface, there is a “considerable need for reference works” in this applications area. This volume serves that function well, especially when complemented with an active search of the more current literature. The rate-determining step in the production of such reference works is the need to tempt practitioners awayfrom the fun of actually doing the science to the more sedate task of writing it all down so that others can benefit from their experience and expertise. In this volume, the writing and the explanations are first-rate. Even with the inevitable temptation to shortchange the mass spectrometryin favor of emphasis of the applications, it is a credit to editors and contributors alike that this does not occur excessively. For instance, it is a genuine enjoyment to see the mass spectral data itself when so many professional journals, even those devoted specifically to the field of mass spectrometry, discourage such publication in favor of tables. Tables after all, only show what is included, while a mass spectrum contains all of the interpreted data as well as some that remains mysterious, to be explained at some later date. The reproduction of the complex figures is excellent, as befits a work of reference. A sense of the spirit of the original conference symposium is still glimpsed in the inclusion of audience questions and speaker answers. Although a few questions track wide of the mark, as a group they provide an excellent sense of the state-of-thescience. Issues of sensitivity, specificity, and the complexity of spectral interpretation recur. And if the questions are phrased in complete sen-
tences, and the answers concise and to the point (and complete with references!), who are we to begrudge editing for the sake of comprehension? Not all of biological mass spectrometryis here in this volume. The pagecount emphasis is heavily on peptides and proteins, with a smaller focus area on carbohydrates and nucleic acids. Pharmaceutical applications are similarly under represented, given the support of modern mass spectrometry in the pharmaceuticalindustry. DNAsequencing merits only a single chapter, the final chapter in the volume, and that chapter is clearly more speculative than descriptive. It is heartening to see inclusion of a chapter on the use of accelerator mass spectrometry in toxicology, since this is an area that has been too deeply hidden in the general literature, but other areas such as carcinogenesis, environmental toxicology, isotopic tracing, metabolic studies, and affinity-based methods (to name a few broad areas) are not represented well here. The price of this symposium volume is steep for an individual, and barely within the reach of libraries. A sad commentary is that libraries sometimes hold symposium volumes such as this one in higher esteem than the lowly monograph, limiting the ability of users to remove the book from the library. If you do get hold of this book, you will surely make your own individual copy of the appendices. The appendices provide the tabulated data important to the biological mass spectrometrist: isotopic mass and abundance values, masses and compositions of commonly occurring amino acids, mass changes that correspond to common posttranslational modifications and protecting groups, structures and masses of sugar groups, and a nomenclature scheme for the description of their dissociations, and finally, a discussion of the meaning and usage of the terms monoisotopic mass, average mass, mass resolution, and mass accuracy. This discussion is the best to be found on the subject anywhere, although the purist will criticize the omission from the discussion of the classical tradeoff between sensitivity and resolution. Sympathy should flow to the instrument operator who must explain why the spectra are not always recorded with the highest attainable instrument
resolution, since the discussion does a complete job of explaining the desirability of such a measurement. It is fitting to close the review of this volume by returning to its own introduction. The National Institutes of Health, National Center for Research Resources was one of many sponsors of this 1994 symposium, as they have sponsored past events in the series. In an introductorychapter, the NIH representative writes ‘What is the next chapter in the mass spectrometry story? First, as word of its successes gets out, scientists in many different disciplines who never heard of mass spectrometry will become increasingly aware of its value in advancing their research projects, and will be eager to become users. More users, of course, will mean more pressure on mass spectrometryresources.“Unfortunately, in the two years since those words were spoken, the situation with respect to the funding of major instrumentation, and the education and training of mass spectrometrists has further deteriorated. In 1996, we have more users. But we have fewer teachers, fewer instrument builders, and fewer researchers to continue the exciting advances that the field has enjoyed over the past decade. One need only update the addresses of the symposium participants to realize the shortage of trained mass spectrometrists with experience in the biological sciences. The fact that prepared and experienced mass spectrometrists are an endangered species constitutes a real problem yet to be confronted. Many potential users grow excited when they learn of the capabilities of modernmass spectrometryfrom valuable books such as the present one. They rush to add mass spectrometry to their analytical arsenal, and will surely be disappointed to find that instruments and approaches are plentiful, while mass spectrometrists themselves are not. If this is the worst of our problems, though, we can surely be a happy and self-satisfied group.
K.L. BUSH DI: K.L. Busch is at the School of Chemistry and Biochem istq Georgia Institute of Technology, Atlanta, GA 30332-0400, USA.
The single term of nuclear magnetic resonance in fact covers a wide range of conceptually very different methods including NMR spectroscopy, time-domain NMR and NMR imaging. Similarly, NMR finds applications not only in chemistry but also in physics, medicine, industrial quality control, and even in petroleum prospecting. Reflecting this, the other 7 volumes cover 5 main aspects of Nuclear Magnetic Resonance: Inorganic applications; polymers and liquid crystals, quadrupolar nuclei; one- and multi-dimensional solution spectroscopy; applications; solid Physics methods; solid-state applications; Biological applications; Instrumentation; organic applications; relaxation topics; theory; Biomedical applications; imaging principles and applications. Each of these major sections is divided into subsections containing related topics which in turn group together several articles. There are over 500 articles, written by internationallyrecognized authoritiesin each field and containing numerous high qualitycolour or black & white photos, drawings and spectra. The articles are extensively cross-referenced and indexed while the reference listsare very complete and up to date. As an example of the structure and, more importantly, the completeness of this Encyclopedia, the subsections and topics of Section 4 are: 4.1 Relaxation Times 4.1.1 Experimental 4.1.2 Theory 4.2 Instrumentation 4.3 Chemical Shifts 4.3.1 Experimental 4.3.2 Theory 4.4 Organic Applications 4.5 Data Processing 4.6 Spin Coupling 4.7 Solvent Studies 4.8 Carbon-13 Studies 4.9 Field Gradient Experiments containing a total of 67 articles. As is clear from these titles, the Encyclopedia covers nearly all aspects of NMR technology, applicaAn initially theory. tions and disconcerting, but finally pleasing aspect of this Encyclopaedia is that the individual articles within any given topic are in fact distributed througl
l
l
l
l
trends in analytical chemistr): vol. 76, no. 7, 1997
hout the 7 volumes in alphabetical order. This means that if you wish to consult all the papers thematically grouped together in ‘4.5 Data Processing”you need to consult Volume 2 for “Computer Assisted Structure Elucidation”, Volume 3 for ‘Data Processing”, ‘Fourier Transform &Linear Prediction Methods”, “Fourier Transform Spectroscopy” and Volume 5 for “Maximum Entropy Reconstruction”. On the other hand, it can be quite fruitful for stochastic information acquisition; ‘Data Processing” being preceded by “Cross Polarization in Solids” and “Cryogenic Magnets for Whole Body Magnetic Resonance Systems”, and followed by ‘Decoupling Methods” and ‘Degenerative Disk Disease Studied by MRI”. It should be pointed out however that usually article titles are chosen in such a way that related subjects are grouped together. Diffusion for example is treated in 7 articles : ‘Diffusion: Clinical Utility of MRI Studies”, ‘Diffusion & Flow in Fluids”, ‘Diffusion Measurements by Magnetic Field Gradient Methods”, ‘Dif-
Mass spectrometry
fusion & Perfusion in MRI”, ‘Diffusion in Porous Media”, ‘Diffusion in Rare Gas Solids” and ‘Diffusion in Solids”, with a total of 451 references. I can make only two suggestions to the Editors for an eventual Supplementary Volume : include an article on industrial applications of Time-Domain (i.e “Low Resolution” or “Wideline’? NMR and an article grouping together all the different types of pulse sequences used in hoheteronuclear, ID-, monuclear, multi-D spectroscopy, imaging and relaxation experiments. This “Encyclopedia of Nuclear Magnetic Resonance” is an essential reference work for anyone using NMR in industry, research or medicine. It should be very useful for those wanting to have information about the theory, the applications and the history of NMR. DOUGLAS
N. RUTLEDGE
DI: D.N. RutledgeLaboratoire de Chimie Analytique, Institut National Agmnomique, 16 rue Claude Bernard 75005 Pan’s, Fence.
in the biological sciences
Mass S;c3ectrometryin the Biological Sciences, edited by A. L. Burlingame and S. A. Car< Humana Press, Totawa, NJ, 1996, xii + 570 pages, $145.00, ISBN 0-89603-3406/96 This symposium volume gathers 26 contributions from a 1994 symposium of the same name. The 1994 meetings was a continuation of the previous meetings on the same subject, proceedings of which are also available. There is a continuing organizingcommittee that organizes and collects the funds for these meetings - the cochairs for the 1994 meeting are the current volume’s editors. Clearly there is a healthy interchange of ideas in these conferences. As might be expected, the emphasis is on applications. A few contributions are more basic and more technique-oriented, such as those emphasizing time-offlight mass spectrometry (Cotter) or Fourier transform ion cyclotron res-
onance instruments (Smith). Other fundamental contributions include those of electrospray ionization (Aplin), matrix-assisted laser desorption ionization (Nelson), MS/MS (Mann), or methods for handling small amounts of sample (Roeraade). Even these contributions are sprinkled liberally with applications in biochemical analysis. Clearly, the mass spectrometry that supports analyses in this area has to be somewhere, developed and by somebody. But it is perhaps best to view this book as the latest volume in a continuous series that chronicles the USE of mass spectrometry in the biological sciences. Development of the science of mass spectrometry still needs to be chronicled elsewhere. The question then becomes how well each volume defines and documents the uses. The technology that underlies the tremendous advances in the field of biological mass spectrometry continues to change very rapidly. A
XIII
trends in analytical chemistry, vol. 16, no. 7, 1997
year represents a long time. A year sees shifts in the scope of problems attempted, and the availability of commercial instruments to adopt as tools in their solution. This 1996 tome documents a 1994 symposium, and the dated nature of the work is too readily apparent. The chapters contain references to the original literature through 1994, and in a few instances, to the first part of 1995 as the final galley proofs were corrected. Even in an age of instant printing and rapid dissemination of information, publication takes time. As a consequence, this volume does not fully represent today’s capabilities in biological mass spectrometry. But as the editors point out in their preface, there is a “considerable need for reference works” in this applications area. This volume serves that function well, especially when complemented with an active search of the more current literature. The rate-determining step in the production of such reference works is the need to tempt practitioners awayfrom the fun of actually doing the science to the more sedate task of writing it all down so that others can benefit from their experience and expertise. In this volume, the writing and the explanations are first-rate. Even with the inevitable temptation to shortchange the mass spectrometryin favor of emphasis of the applications, it is a credit to editors and contributors alike that this does not occur excessively. For instance, it is a genuine enjoyment to see the mass spectral data itself when so many professional journals, even those devoted specifically to the field of mass spectrometry, discourage such publication in favor of tables. Tables after all, only show what is included, while a mass spectrum contains all of the interpreted data as well as some that remains mysterious, to be explained at some later date. The reproduction of the complex figures is excellent, as befits a work of reference. A sense of the spirit of the original conference symposium is still glimpsed in the inclusion of audience questions and speaker answers. Although a few questions track wide of the mark, as a group they provide an excellent sense of the state-of-thescience. Issues of sensitivity, specificity, and the complexity of spectral interpretation recur. And if the questions are phrased in complete sen-
tences, and the answers concise and to the point (and complete with references!), who are we to begrudge editing for the sake of comprehension? Not all of biological mass spectrometryis here in this volume. The pagecount emphasis is heavily on peptides and proteins, with a smaller focus area on carbohydrates and nucleic acids. Pharmaceutical applications are similarly under represented, given the support of modern mass spectrometry in the pharmaceuticalindustry. DNAsequencing merits only a single chapter, the final chapter in the volume, and that chapter is clearly more speculative than descriptive. It is heartening to see inclusion of a chapter on the use of accelerator mass spectrometry in toxicology, since this is an area that has been too deeply hidden in the general literature, but other areas such as carcinogenesis, environmental toxicology, isotopic tracing, metabolic studies, and affinity-based methods (to name a few broad areas) are not represented well here. The price of this symposium volume is steep for an individual, and barely within the reach of libraries. A sad commentary is that libraries sometimes hold symposium volumes such as this one in higher esteem than the lowly monograph, limiting the ability of users to remove the book from the library. If you do get hold of this book, you will surely make your own individual copy of the appendices. The appendices provide the tabulated data important to the biological mass spectrometrist: isotopic mass and abundance values, masses and compositions of commonly occurring amino acids, mass changes that correspond to common posttranslational modifications and protecting groups, structures and masses of sugar groups, and a nomenclature scheme for the description of their dissociations, and finally, a discussion of the meaning and usage of the terms monoisotopic mass, average mass, mass resolution, and mass accuracy. This discussion is the best to be found on the subject anywhere, although the purist will criticize the omission from the discussion of the classical tradeoff between sensitivity and resolution. Sympathy should flow to the instrument operator who must explain why the spectra are not always recorded with the highest attainable instrument
resolution, since the discussion does a complete job of explaining the desirability of such a measurement. It is fitting to close the review of this volume by returning to its own introduction. The National Institutes of Health, National Center for Research Resources was one of many sponsors of this 1994 symposium, as they have sponsored past events in the series. In an introductorychapter, the NIH representative writes ‘What is the next chapter in the mass spectrometry story? First, as word of its successes gets out, scientists in many different disciplines who never heard of mass spectrometry will become increasingly aware of its value in advancing their research projects, and will be eager to become users. More users, of course, will mean more pressure on mass spectrometryresources.“Unfortunately, in the two years since those words were spoken, the situation with respect to the funding of major instrumentation, and the education and training of mass spectrometrists has further deteriorated. In 1996, we have more users. But we have fewer teachers, fewer instrument builders, and fewer researchers to continue the exciting advances that the field has enjoyed over the past decade. One need only update the addresses of the symposium participants to realize the shortage of trained mass spectrometrists with experience in the biological sciences. The fact that prepared and experienced mass spectrometrists are an endangered species constitutes a real problem yet to be confronted. Many potential users grow excited when they learn of the capabilities of modernmass spectrometryfrom valuable books such as the present one. They rush to add mass spectrometry to their analytical arsenal, and will surely be disappointed to find that instruments and approaches are plentiful, while mass spectrometrists themselves are not. If this is the worst of our problems, though, we can surely be a happy and self-satisfied group.
K.L. BUSH DI: K.L. Busch is at the School of Chemistry and Biochem istq Georgia Institute of Technology, Atlanta, GA 30332-0400, USA.