ISSN: 0022-1198
CODEN: JFSCA
Published Online: 1 April 1978
Page Count: 7

A Study of False Positives in the Chemical Identification of Marihuana
Hughes, RB
Forensic chemist and supervisory forensic chemist, Drug Enforcement Administration, Mid-Atlantic Regional Laboratory,

Warner, VJ
Forensic chemist and supervisory forensic chemist, Drug Enforcement Administration, Mid-Atlantic Regional Laboratory,

(Received 15 June 1977; accepted 1 August 1977)

Abstract

Many authors have reported using the Duquenois, Duquenois-Negm, Duquenois-Levine, or modified Duquenois-Levine color tests on various substances with varying results. Some authors [1] apparently consider any resultant color to be a positive response. Recently this diversity of testing methods has been used by defense lawyers in an attempt to confuse judges and juries. Therefore, a search of the literature was conducted for the various substances reported to give a positive response to any of the above methods; all of those that were commercially available were tested with the modified Duquenois-Levine test and thin-layer chromatography (TLC) employed by this laboratory for marihuana identification. In addition, other compounds of similar structures were selected and tested in like manner, as were minor components of Cannabis resin [2]. Another major objective was to determine if a mixture of materials that would lead to a false positive identification of marihuana could be made.

Keywords:

Paper ID: JFS10761J
DOI: 10.1520/JFS10761J
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