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NCJRS Abstract

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NCJ Number: 136015 Find in a Library
Title: Comparison Analysis of Illicit Cocaine Samples
Journal: Journal of Forensic Sciences  Volume:37  Issue:2  Dated:(March 1992)  Pages:436-445
Author(s): K E Janzen; L Walter; A R Fernando
Date Published: 1992
Page Count: 10
Type: Test/Measurement
Format: Article
Language: English
Country: United States of America
Annotation: Previous successful comparisons of cocaine samples adulterated by numerous other drugs and sugars have resulted in requests by drug enforcement personnel for comparisons of cocaine samples that are relatively pure and unadulterated; accordingly, this study developed a method for a detailed analysis of illicit cocaine samples to analyze the differences and similarities among them.
Abstract: Preliminary results have shown the presence of four minor cocaine-related alkaloids in most illicit cocaine samples; these are tropacocaine, norcocaine, and and the isomers cis-cinnamoylcocaine and trans-cinnamoylcocaine. The variations in the relative amounts of these alkaloids suggest that they might be useful for comparison purposes. Gas chromatography analysis of concentrated cocaine samples showed the reproducibility of the area ratios of tropacocaine, norcocaine, and cis- and trans-cinnamoylcocaine to cocaine within subsamples of large lots of illicit cocaine. These intrasample variations were much smaller than the variations among a random sample of cocaine exhibit materials submitted for routine analysis and quantitation. To draw meaningful conclusions regarding the similarity of two cocaine samples, data must also be available to show their dissimilarity to most of the unrelated cocaine samples. A large database of alkaloid/cocaine area ratios can quickly be searched by computer for any possible matches. The combination of four ratios for each cocaine sample greatly increases the selectivity of the comparison. Positive matches can then be further checked by visual comparison of chromatograms. 3 figures, 2 tables, and 21 references
Main Term(s): Cocaine; Drug detection
Index Term(s): Comparative analysis
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