Using Native Commands to Search
Chemical Abstracts Online

Introduction Commands Needed to Search Sample Search Does HSU Library have the item? Exercises

Introduction

Chemical Abstracts Online (CAS 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 published in paper format as well as online. [HSU Library has the paper format from 1907 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 2008, CA has more than 26 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 some pre-1907 journal articles and patents included in CA.
REG -- Registry File -- a chemical structure and dictionary database of substances identified by the Chemical Abstracts Service Registry System -- currently contains over 93 million chemical substances & sequences (See CAS Registry Number and Substance Counts for the most recent data)
CIN -- Chemical Industry Notes - a bibliographic database covering business news since 1974 in all areas of the chemical industry.
LCA -- Learning CA file -- designed to help you learn how to use CA -- a very small subset of CA makes up the file.
LREG -- Learning Registry file -- a companion file to LCA.

CAS Online is available for searching via the Library home page<http://library.humboldt.edu>. Click on Articles and Databases (under Quick Links) 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 CAS Online only during restricted times. It is strongly recommended that you review the search guides Using CAS Databases on STN and Using the CAS Registry File on STN before beginning your search.

Think about the search terms you want to use BEFORE you go online. Look up terms in Chemical Abstracts Index Guide (abstr QD 1 A51) to find preferred terminology and registry numbers. Note that CAS Online often uses abbreviations -- see CAS Standard Abbreviations 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 will want to consult How to Find CAS Registry Numbers for Chemical Compounds. Additional guides to searching CAS Online may be found at CAS Learning Center - STN Resources page.

Commands Needed to Search CAS Online

The basic commands you will use most often and their meanings are listed below:

Command or Key	Meaning (What It Does)	Examples
file reg	Search Registry File (to identify a chemical substance and obtain the CAS Registry Number). The Registry File covers 1957-date and has more than 93,000,000 records as of January 2008.	file reg
file ca	Search Chemical Abstracts 1907 to present.	file ca
s	Search (there is a limit of 256 characters for search statements)	s formaldehyde
search	Search (system will prompt you for information).	search
e	View inverted index. You can see the neighboring terms.	e wood w/au
expand	View inverted index (system will prompt you for information).	expand
and, or, not	Boolean operators (see Using Boolean Operators for an explanation).	s digitoxin and toxicity s methanol or ethanol s air not water
(w) or (nw)	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
(a) or (na)	Terms must be next to each other (or within n number of words) in any order. CAS 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
(L) or (l)	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?
#	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
d	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 compound.	d l3 1-10 bib,abs d l4 1-5 all d l2 ide
d scan	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
display	Display (system will prompt you for information).	display
print	NOTE: You are advised NOT to use OFFLINE PRINT as this will deliver results via snail mail to HSU Library. 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 gives you enough information to identify the chemical compound. *ALSO 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.	print
end	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
logoff y	End session and exit the system. Please be sure to logoff when you finish your search!!	logoff y
logoff hold	End session but hold it for 60 minutes (so you may resume your search without keying it all in again).	logoff hold

Specific fields 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:

Field Name Field tag Example

Basic Index (contains single words from title and indexing fields, as well as CAS Registry Numbers) None
(or /bi) s 50-21-5
s antitumor/bi

Chemical Name -- complete name of chemical compound /cn s formaldehyde/cn
s benzoic acid/cn

Abstract /ab s (water(1a)soluble/ab)

Author Name /au s barton j?/au

Corporate Source /cs s humboldt state/cs

Language /la 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. /mf s c21h23clfno2/mf
s C21H23ClFNO2/mf

Publication Year /py s 1997-2003/py
s 2002/py

Document Type /dt 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)

Sample Search

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 Interscience.

Some full text is linked to from within CAS Online. If the citation or reference has a button above it, click on it. You will then be taken to the ChemPort-Connection 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 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 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. If you are in the library, you may use CASSI: Chemical Abstracts Service Source Index (abstr QD 1 A523) and/or Periodical Title Abbreviations: by abbreviation (ref Z 6945 A2 P47) - both are located near the Information Desk on the first floor. Periodical Title Abbreviations has additional online and print resources you can use to decipher journal abbreviations. Do not guess at what abbreviations mean!

For example, you have found a reference to J. Nat. Prod. Simply type j nat prod into the Journal & Newspaper Finder and you will see:

Simply click on the Journal of Natural Products link, then click again on the ACS Publications link on the next page that appears, 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 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 two weeks or longer) so allow for this in doing your research.

Exercises in Searching CAS Online

NOW you can test your knowledge of CAS Online by completing the Chemical Abstracts Online Exercises.

Send comments and suggestions about this page to: Sharon Chadwick .

Last Updated: January 24, 2008

Field Name	Field tag	Example
Basic Index (contains single words from title and indexing fields, as well as CAS Registry Numbers)	None (or /bi)	s 50-21-5 s antitumor/bi
Chemical Name -- complete name of chemical compound	/cn	s formaldehyde/cn s benzoic acid/cn
Abstract	/ab	s (water(1a)soluble/ab)
Author Name	/au	s barton j?/au
Corporate Source	/cs	s humboldt state/cs
Language	/la	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.	/mf	s c21h23clfno2/mf s C21H23ClFNO2/mf
Publication Year	/py	s 1997-2003/py s 2002/py
Document Type	/dt	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)

Using Native Commands to Search Chemical Abstracts Online