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A guide for the laboratory information management system (LIMS) for light stable isotopes--Versions 7 and 8

January 1, 2000

The reliability and accuracy of isotopic data can be improved by utilizing database software to (i) store
information about samples, (ii) store the results of mass spectrometric isotope-ratio analyses of samples, (iii)
calculate analytical results using standardized algorithms stored in a database, (iv) normalize stable isotopic
data to international scales using isotopic reference materials, and (v) generate multi-sheet paper templates
for convenient sample loading of automated mass-spectrometer sample preparation manifolds. Such a
database program, the Laboratory Information Management System (LIMS) for Light Stable Isotopes, is
presented herein. Major benefits of this system include (i) a dramatic improvement in quality assurance, (ii)
an increase in laboratory efficiency, (iii) a reduction in workload due to the elimination or reduction of
retyping of data by laboratory personnel, and (iv) a decrease in errors in data reported to sample submitters.
Such a database provides a complete record of when and how often laboratory reference materials have
been analyzed and provides a record of what correction factors have been used through time. It provides an
audit trail for laboratories.
LIMS for Light Stable Isotopes is available for both Microsoft Office 97 Professional and Microsoft
Office 2000 Professional as versions 7 and 8, respectively. Both source code (mdb file) and precompiled
executable files (mde) are available.
Numerous improvements have been made for continuous flow isotopic analysis in this version
(specifically 7.13 for Microsoft Access 97 and 8.13 for Microsoft Access 2000). It is much easier to import
isotopic results from Finnigan ISODAT worksheets, even worksheets on which corrections for amount of
sample (linearity corrections) have been added. The capability to determine blank corrections using isotope
mass balance from analyses of elemental analyzer samples has been added. It is now possible to calculate
and apply drift corrections to isotopic data based on the time of day of analysis. Whereas Finnigan
ISODAT software is confined to using only a single peak for calculating delta values, LIMS now enables
one to use the mean of two or more reference injections during a continuous flow analysis to calculate delta
values. This is useful with Finnigan?s GasBench II online sample preparation system. Concentrations of
carbon, nitrogen, and sulfur can be calculated based one or more isotopic reference materials analyzed with
a group of samples. Both sample data and isotopic analysis data can now be exported to Excel files. A
calculator for determining the amount of sample needed for isotopic analysis based on a previous amount of
sample and continuous flow area is now an integral part of LIMS for Light Stable Isotopes. LIMS for Light
Stable Isotopes can now assign an error code to Finnigan elemental analyzer analyses in which one of the
electrometers has saturated due to analysis of too much sample material, giving rise to incorrect isotopic
abundances. Information on downloading this report and downloading code and databases is provided at the
Internet addresses: http://water.usgs.gov/software/geochemical.html or
http://www.geogr.uni-jena.de/software/geochemical.html in the Eastern Hemisphere.

Publication Year 2000
Title A guide for the laboratory information management system (LIMS) for light stable isotopes--Versions 7 and 8
DOI 10.3133/ofr00345
Authors Tyler B. Coplen
Publication Type Report
Publication Subtype USGS Numbered Series
Series Title Open-File Report
Series Number 2000-345
Index ID ofr00345
Record Source USGS Publications Warehouse