The Adams Library: Now with mass spectra and
retention times for 2,205 compounds
Dr. Robert Adams, December 8, 1939 ~ December 2, 2020.
Dr. Robert Adams, author of Essential Oil Components by GC/MS, passed away in St. George, Utah on December 2, 2020. We extend our condolences to Dr. Adams family, friends, and colleagues.
His wish was for the Essential Oils Library to continue to be available to customers after his death. To ensure this, he transferred the rights to the library to Diablo Analytical and asked that the price be reduced to make the library more accessible to all. The new pricing will be available for all sales occurring on or after December 1st, 2020.
Important Announcement: The National Institute of Standards and Technology (NIST) has licensed the spectra contained in the Adam's Library, and will be including them in the NIST 23 Mass Spectral Library, which will be released on Monday, June 5, 2023. If you already own a copy of an earlier version of the full NIST Library, you can upgrade to NIST 23, or you can purchase a new license of the full NIST 23 Library once it has been released. If you purchase either the upgrade or the new license at the current prices prior to June 5th, 2023 you will receive the NIST 20 version of the library and a free upgrade to NIST 23 when it is released.
Note: Diablo Analytical will continue to sell the standalone versions of the Adam's Library for customers who don't need the full NIST library.
The Library

The Essential Oils by GC/MS library was born over 40 years ago, when Professor Robert P. Adams began his research on terpenes, and generated the Adams Library with his research and the contributions of dozens of respected plant biologists around the world.
Is your component in the library?
All 2205 components are listed in a searchable appendix.
Ready to Order?
The Essential Oils library is available in NIST, Agilent ChemStation/MassHunter, and Shimadzu formats and can either be downloaded, or delivered in USB flash drive or DVD media.
Available Formats
Diablo Analytical offers the Essential Oils Library for sale in the following formats:
- NIST format for use with the NIST MS Search program and other search programs that can read the NIST library format
- Agilent Technologies ".L" format for the MSD ChemStation/MassHunter data systems
- Shimadzu format
New: A new "enhanced" version of the NIST formatted library that includes electronic structures is now available. The enhanced version also includes:
- Chiral structures are displayed and are searchable for all compounds.
- Retention Index is in the NIST comments field, with chromatographic conditions disclosed.
- Retention index is now displayed in the NIST search report, thus adding easy secondary confirmation of compound identity.
- InChlKey provides access to PubChem for structure confirmation.
- Compound names have retention time prefix removed. Now you can perform searches by compound name.
Note: Because the retention time prefix has been moved from the compound name field to the comments field in the enhanced NIST version of the library, your search program must be able to display the comments field to see the retention time for the compound.
Existing owners of the NIST version of the Essential Oil Components Database may order upgrades.
If you wish to evaluate the library, a demo version, which is available in multiple formats, is available on request. Please click the button below, fill in the form, and a download link will be provided.
Would You Like the E-Book?
Robert Adams has consistently updated the companion book to the library. The current edition, "Identification of Essential Oil Components by Gas Chromatography/Mass Spectrometry", ed. 4.1, contains all of the spectra, retention times, structures, and synonomy of the searchable library.
Although the library has carefully cataloged precise spectra and retention times for identification, the human eye is a powerful confirmation tool. The book is an additional important identification tool with the library.
The published book is out of print. The e-book is available for free, in appreciation to the many colleagues who have contributed to the Adams Library. Click on the button to request your free e-book.
Would You Like to Learn More About the Author, Robert Adams?
Electronic copies of Prof. Adams publications are available by clicking here.
To order your copy of the 4th edition of "Junipers of the World: The genus Juniperus", click here