Caveat Chemicus: Practical Guidance to Searching Chemical Abstracts

Article excerpt

by guest columnist Dana L. Roth Senior Technical Information Librarian California Institute of Technology Library System

Sci-tech information searchers have long recognized Chemical Abstracts (CA) as a premier science and engineering database. In fact, some have called the "chemical" in Chemical Abstracts a restrictive misnomer and suggested that the title might reasonably be changed to Chemistry, Science, and Engineering Abstracts. This high regard stems from CA's broad subject coverage, which extends to the chemical aspects of astronomy, biology, education, engineering, economics, geology, history, mathematics, medicine, and physics. It also denotes CA's extensive format coverage which includes articles from journals and regularly published conference proceedings (73 percent), articles from one-time or first-time conference proceedings (7 percent), dissertations (2 percent), technical reports (1 percent), patents (16 percent), and edited research monograph chapters (1 percent). CA currently carries abstracts for more than 8,000 source items (including Internet documents since 1995) and produced over 700,000 abstracts in 1996[1]. At the end of 1996, over 78 percent (13.2 million) of all the abstracts published since 1907 (16.9 million) were available online[2].

"Chemistry," as defined by the Chemical Abstracts Service (CAS), "is both a basic and an applied science that includes the study of matter (atoms, molecules, and subatomic particles; elements and compounds; rocks and minerals; mixtures and multiphasic or composite materials such as plastics, ceramics, and concrete); its occurrence, composition, preparation, structure, and properties; its chemical reactions and changes of state; its detection, determination, technology and uses; and apparatus designed specifically for carrying out such studies and measurements. Chemical principles, laws, and methods interrelate in one way or another with essentially every other branch of science and technology"[3]. Some examples of the interrelationships with other disciplines include mineralogy of lunar dust samples; presence of lipids in mitochondria, blood, or liver tissue; corrosive effects of acids on aluminum alloys, laser-induced thermionic emission from tantalum, microstructure of steel, biosynthesis of DNA from nucleotides, and new methods of petroleum refining[3].

Another measure of CA's interdisciplinary nature comes from the types of substances registered in the CAS Registry File, which now totals over 17 million substances[1]. These are Organic, Organometallic, Inorganic and Coordination Compounds, Metals, Alloys, Minerals, Elements, Isotopes, Nuclear Particles, Nucleic Acids, Proteins, Polymers, & Nonstructurable Materials (primarily commercial preparations). With some exceptions, e.g., substances requiring Environmental Protection Agency registration, CA covers known chemical structures.

Or look at the widely interdisciplinary nature of the top 10 journals they cover (found in a rank order listing of the "Most Frequently Cited Journals in CA"[4]. These are Materials Research Symposium Proceedings, Journal of Biological Chemistry, Physical Review B, Proceedings of SPIE, Journal of Applied Physics, Proceedings of the National Academy of Sciences of the USA, Journal of Chemical Physics, Applied Physics Letters, American Journal of Physiology, and the Journal of the American Chemical Society.

In addition, CA's patent coverage now includes 29 national patent offices and two international agencies[5]. CAS routinely abstracts the first issued patent document and relates all equivalents through its (print or CD-ROM) Patent Index. This, and a significant expansion of coverage, explains the preponderance of Japanese patents in the last 20 years and the increasing number of WIPO and EPO patent documents in recent years 2. Improvements in patent coverage, in recent years, are also reflected in the CAS Patent Coverage Table[5]. …