Using Native Commands to Search
Chemical Abstracts Online
NOTE: There is a PowerPoint presentation that covers the key points (but not all) of this guide.
Does HSU Library have the item? | Exercises
Introduction
Chemical Abstracts Online (CA Online) is *THE* major index/abstract to the world's literature of chemistry and chemical engineering. Produced by Chemical Abstracts Service (CAS), Chemical Abstracts is currently only published online. [HSU Library has the print (paper) format from 1911 through 1991. The call number is abstr QD 1 A51 and it may be found in the reference section of the first floor.] Chemical Abstracts indexes thousands of journals, patents, technical reports, books, conference proceedings, and dissertations from around the world.
HSU campus users may access the following files:
- CA -- Chemical Abstracts 1907 to date. As of January 2012, CA has more than 35 million records. The 1907-1966 records contain bibliographic information, abstracts, index entries, and page images from printed CA in TIFF format. See Searching pre-1967 references in CAplus and CA for more information. There are over 224,000 pre-1907 journal articles and patents included in CA.
- REG -- Registry File. The Registry File is a chemical structure and dictionary database of substances identified by the Chemical Abstracts Service Registry System. As of February 2012, REG contains over 65 million organic & inorganic substances as well as over 63 million sequences (See CAS Database Content at a Glance for the most recent data). REG now contains Experimental and Predicted Property Data for over 53 million substances.
- CIN -- Chemical Industry Notes. CIN is a bibliographic database covering business news since 1974 in all areas of the chemical industry. Go to CIN when you need current business news related to production, pricing, sales, facilities, products and processes, or corporate and government activities.
- LCA -- Learning CA file. LCA is designed to help you learn how to use CA -- a very small subset of CA makes up the file.
- LREG -- Learning Registry file. LREG is a companion file to LCA which is designed to help you learn how to use REG.
CA Online is available for searching via the Library home page (http://library.humboldt.edu). Click on Articles & Databases (under Research Tools) and then on Chemistry in the Databases By Subject list. Choose Chemical Abstracts Online from the resulting list of indexes. [If you are using a computer from off campus, you will prompted for authentication information. See Off Campus Access to Databases for details.] The system will then automatically log into STN International in Columbus, Ohio. You will be asked to accept the terms and conditions for academic institutions (simply type y). A list of NEWS items will appear and then the system will prompt you to put in your search with an arrow (→).
Begin your search by selecting the file you wish to search, e.g., file ca. Then enter your search terms using the commands shown in the tables below. Please enter your search as quickly as possible because charges accrue from the second you logon until you logoff.
You may search CA Online only during restricted times. It is recommended that you review the resources under Getting Started on the Guide for New STN Searchers before beginning your search. You may also want to complete some of the training modules on STN Basics Tutorial.
Think about the search terms you want to use BEFORE you go online. You may look up terms in Chemical Abstracts Index Guide (abstr QD 1 A51 in the reference collection) to find preferred terminology and registry numbers. Note that CA Online often uses abbreviations -- see CAS Standard Abbreviations & Acronyms for details as well as a listing of abbreviations used. See Identifying Concepts and Generating Search Terms for basic search strategy information. The most precise way to search for chemical substances is by CAS registry number so you may also want to consult How to Find CAS Registry Numbers for Chemical Compounds.
Commands Needed to Search CA Online
The basic commands you will use most often and their meanings are listed below:
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Meaning (What It Does) |
Examples |
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Search Registry File
(to identify a chemical substance and obtain the CAS Registry Number).
The Registry File covers 1957-date and has more than 128 million
records as of February 2012.
|
file reg |
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|
Search Chemical Abstracts
1907 to present. |
file ca |
|
|
Search (there is a limit of 256
characters for search statements) |
s formaldehyde |
|
|
Search (system will prompt you for
information). |
search |
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|
View inverted index. You can
see the neighboring terms. |
e wood w/au |
|
|
View inverted index (system will
prompt you for information). |
expand |
|
|
Boolean operators (see Using
Boolean Operators for an explanation).
|
s digitoxin and toxicity
s methanol or ethanol s air not water |
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|
Terms must be adjacent (or within n number of words) in the order entered. A space between two terms is assumed to be (w); e.g., s diels alder gives the same results as s diels(w)alder. |
s diels(w)alder
s diels alder s carbon(1w)nmr |
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|
Terms must be next to each
other (or within n number of words) in any
order. CA Online uses many inverted subject headings (e.g.;
chromatography, gas) so use (a) if you are not sure of the order
of terms.
|
s butyric(a)acid
s gas(2a)chromatography |
|
|
Terms must be in the same field
(e.g., title, index terms, etc.) Especially useful when searching name
segments (i.e., parts or fragments of a chemical name) in the Registry
file. |
s copper(l)carboxylate |
|
|
Truncation: ANY number
of characters may appear at the end of the root; e.g., carboxyl?
will retrieve carboxyl, carboxylate, carboxylic,
etc.
|
s carboxyl?
s odor? |
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|
Used at end of term to indicate
singular or plural; e.g., carboxylate#
will retrieve carboxylate
as well as carboxylates. |
s carboxylate#
s skunk# |
|
|
One variable character (cannot be
used at beginning of term). Good for variant spellings; e.g., colo!r
will retrieve color
or
colour. |
s colo!r
s sulf!nyl s phosphor!us |
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|
Display or view the results online. Put the line number or L- number of the answer set you wish to display, the number(s) or range of answers, and the format in which to display answers, e.g., d L3 1-25 bib,abs For file CA, the most useful format is bib,abs (bibliographic information and abstract). The format all will give you the indexing terms in addition to the bibliographic information and abstract. For file REG, the most useful format is ide which provides a structure diagram and enough information to identify the chemical compound. NOTE: You may use the Transcript Assistant or your browser's Print or Save As button to print and/or download the screen displays. |
d L3 1-10 bib,abs d L4 1-5 all d L2 ide |
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Display Scan: Portions of answers
(section code, title, indexing terms) will be displayed in random order
so you can determine if the search is retrieving satisfactory results. |
d scan L4 |
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Display (system will prompt you
for information). |
display |
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|
NOTE: You are advised NOT to use OFFLINE PRINT as this will deliver results via snail mail to HSU Library and we will not know how to deliver them to you. Have results emailed or faxed to you. You will be asked to give your email address or fax number. Be certain to add .internet to the end of your email address, e.g., ssc1@humboldt.edu.internet or your results will not reach you. Do NOT put a period at the end!! The system will then prompt you for the L- number, number of answers (be careful to only print answers you NEED -- this should be a very low number in the registry file), and the format you want the answers to have. The most useful format for file ca is bib, abs (bibliographic information and abstract). For file reg, the most useful format is ide which provides a structure diagram and gives you enough information to identify the chemical compound. PLEASE NOTE: You may also use the Transcript Assistant or the browser's Print or Save As button to print and/or download the screen displays. |
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|
|
Use at any colon (:) prompt to terminate
the command or to get out of a loop. If you ever get stuck and cannot
get the computer to respond, use the end command. The system
will give you an arrow (→) prompt and you can resume your search. |
end |
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End session and exit the system. Please be sure to logoff when you finish your search!! |
logoff y |
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|
End session but hold it for 60 minutes
(so you may resume your search without keying it all in again). |
logoff hold |
Specific fields (or parts of the record) may be searched by adding a field tag to the search term. Field tags differ for each database and are listed on the CA Database Summary Sheet and the REGISTRY Database Summary Sheet. The most useful ones are listed below:
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|
|
Examples |
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Basic Index (contains single
words from title and indexing fields, as well as CAS Registry Numbers) |
(or /bi) |
s 50-21-5
s antitumor/bi |
|
Chemical Name -- complete
name of chemical compound |
|
s formaldehyde/cn
s benzoic acid/cn |
|
Abstract |
|
s (water(1a)soluble/ab) |
|
Author Name |
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s barton j?/au |
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Corporate Source |
|
s humboldt state/cs |
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Language |
|
s L3 and eng/la
|
|
Molecular Formula (Registry
file only) - Arrange elements in Hill System order, i.e., C first,
H next, all remaining elements in alphabetical order. |
|
s c21h23clfno2/mf
s C21H23ClFNO2/mf |
|
Publication Year |
|
s 2002-2012/py
s 2009/py |
|
Document Type |
|
s r/dt
s antitumor not p/dt Document types are REVIEW (r/dt), PATENT (p/dt), JOURNAL (j/dt), CONFERENCE (c/dt), DISSERTATION (d/dt), and TECHNICAL REPORT (t/dt) |
This sample search on 2-Methylquinoline as a Component of the Spray of the Spotted Skunk or the Hog-Nosed Skunk shows the use of commands as well as a full record for one item retrieved.
Does HSU Library have the item?
Once you have a list of citations or references on the topic you are researching, you must determine if HSU Library has the article, book, report or document cited. Check HSU Library Catalog for books, reports, dissertations, and the complete titles of periodicals (journals, magazines) containing articles of interest. For periodicals or journal articles be sure to use the Journal & Newspaper Finder, a searchable guide to the thousands of journals and other serials accessible online (fulltext) as well as to the print periodicals in HSU Library. You will find all of the American Chemical Society journals online as well as many published by leading scientific publishers such as Elsevier and Wiley.
Some full text is linked to from within CA Online. If the citation
or reference has a 
button or link above it, click on it. You will then be taken to the
ChemPort CAS Full-text Options page for that citation.
If there are any "live" options in the Document Options column, click
on the desired option and the full text of the article will be displayed
if available. However, all full text available at HSU Library is NOT indicated
here. Keep in mind that you can always use the Journal
& Newspaper Finder and/or HSU
Library Catalog to find articles both in electronic and print form.
Chemical Abstracts often uses abbreviations for the names of journals which you will need to decipher. You can search for the abbreviated title in the Journal & Newspaper Finder (by clicking on the EXACT radio button) but this is limited to titles to which HSU Library has access. If you do not find the title in the Journal & Newspaper Finder you will need to consult other resources. Try searching CASSI: Chemical Abstracts Service Source Index, a database of journal abbreviations & titles for publications indexed by CAS since 1907. Journal Title Abbreviations has additional online and print resources to help with journal abbreviations. Do not guess at what abbreviations mean!
For example, you have found a reference to a 1987 article published in J. Nat. Prod. Simply type j nat prod into the Journal & Newspaper Finder and click on the Exact radio button. You will see a link to Journal of Natural Products as shown below:
Simply click on the Journal of Natural Products link and you will see the SFX page below:
Since the article you want was published in 1987, click on the American Chemical Society Legacy Archives link and you will be connected to the Journal of Natural Products for 1979 to date. This is a full text publication so you can view the entire article online. If you know the year, volume, issue and start page for the article you want, you may put that information in the boxes and go directly to that article.
If the Library does not have the article or book you want, you will have to use Interlibrary Loan to get the item. This takes time (can take up to one week or longer) so allow for this in doing your research.
Exercises in Searching CA Online
NOW you can test your knowledge of CA Online by completing the Chemical Abstracts Online Exercises.