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Comparison of Intra-Day and Inter-Day Variation in LIBS Spectra

NCJ Number
Forensic Chemistry Volume: 3 Dated: March 2017 Pages: 36-40
Date Published
March 2017
5 pages
This article reports on an experiment designed to investigate the claim that there is higher variation in the experiments conducted on different days compared to the experiments conducted on the same day.

Laser Induced Breakdown Spectroscopy (LIBS) is an analytical chemistry technique that has the potential to identify and measure the elements in a substance of interest. LIBS is applicable for any phase (solid, liquid or gas). LIBS has gained importance in the fields of material identification, biomedical science, forensics, military, art, and archaeology in recent years. In spite of its many advantages over other instruments, it has a few drawbacks, such as poor precision and repeatability. Different spectra may be observed for the same sample over successive runs. This indicates poor precision of the instrument. The current study examined the variability in the spectra between the runs on the same day, and the variability between runs on different days, using samples from a standard reference glass, and discusses the conclusions that can be drawn from the results. The study concluded that additive log-ratio transformation (ALR) should be used for LIBS data. Variation in LIBS data collected on the same day or different days was not different; therefore, LIBS may be a reliable instrument and may be used for forensic purposes in the future. (publisher abstract modified)

Date Published: March 1, 2017