NCJ Number
226740
Journal
Problems of Forensic Sciences Volume: 76 Dated: 2008 Pages: 412-419
Date Published
2008
Length
8 pages
Annotation
This paper presents the findings of an application of the method of inductively coupled plasma optical emission spectrometry (ICP-OES) to the analysis of samples of internal organs, blood, and urine, so as to determine the presence of mercury and lead in the samples.
Abstract
The findings indicate that the ICP-OES method does detect mercury and lead at concentrations that occur in biological material when there is acute poisoning; however, the method showed relatively weak sensitivity to mercury and lead when their concentrations were close to normal levels. Preliminary results suggest that similar conclusions can be drawn regarding other elements normally present in biological material at low concentrations, e.g., thallium, chromium, and arsenic, but whose concentrations are significantly higher in cases of acute poisoning. The study used samples of blood, urine, brain, liver, kidney, and stomach. In the ICP-OES method, a solution of the sample is introduced into argon plasma, whose temperature in various parts of the torch is between 6,000 K and 10,000 K. Various processes occurring in the flame at this temperature include solvent evaporation; the melting and evaporation of the sample; atomization and ionization; and most importantly, excitation of atoms, which emit electromagnetic radiation when they return to the atomic ground state. This radiation is characteristic for particular elements, because emission spectra are determined by the electron structure of the atom. The intensity of the emitted radiation at wavelengths that are characteristic for the given element depends on the number of its atoms present in the sample. This is the basis of quantitative analysis. Significant problems in the ICP-OES method are spectral interferences caused by overlapping of emission lines of the analyte with lines or bands of emission and absorption of “interferents” (other components in the sample). 6 tables and 12 references