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The Chemical Educator
ISSN: 1430-4171 (electronic version)
Abstract Volume 22
(2017) pp 197-200
Forensic Analysis in the Instrumental Laboratory: A
Nondestructive Ultrasound-enhanced Aqueous Extraction Coupled With GC-MS Analysis of Cocaine on US
Banknotes
Yiwei Deng*,†, Aaron Zhang†, Justin Kandah†, Steven Akins†and Khadija Jawad‡
†Department of Natural Sciences, University of Michigan-Dearborn, Dearborn, MI 48128, dengy@umich.edu; ‡Department of Chemistry, Purdue University, West Lafayette, IN 47907
Received June 19, 2017. Accepted October 23, 2017.
Published: 4 Devember 2017
Abstract. This
experimental exercise with forensic application was developed for an advance
undergraduate analytical chemistry course. A simple, nondestructive
ultrasound-enhanced aqueous extraction coupled with gas chromatography-mass
spectrometry (GC-MS) was modified and adopted for the determination of cocaine
on US banknotes. The students were asked to randomly collect paper currency
from the Metro Detroit area and utilized the method to identify and quantify
cocaine on paper currency collected. The samples were initially extracted with
water. Cocaine in the aqueous phase was further extracted by hexane. A GC-MS
was used for identification and quantitation. Cocaine was detected in 67%
of the banknotes collected from general circulation. The
lab exercise introduces a forensic theme using basic analytical chemistry
skills and modern instrumentation. It also engages students in problem–solving
and cooperative learning.
Key Words: Laboratories and Demonstrations; analytical chemistry
(*) Corresponding author. (E-mail: dengy@umich.edu)
Article in PDF format (205 KB) HTML format
Supporting Materials:
Instructions for instructors and students, as well as procedural details
and instrumental settings are provided in laboratory documentation available in
this issue of Chemical Educator Online.
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