1. Comparison of Heroin Samples with Vinegar
ABSTRACT
RESULTS
MATERIALS/PROCEDURE
Presently, very little information about the volatile components in heroin can be found in scientific literature. There exists even less information on which of these volatile components from heroin produce a canine alert. Most likely due to a lack of comprehensive sequential analytical procedures used to analyze heroin components, particularly when some of those components may change in heroin samples during the illegal drug trade during manufacture and transport. This study was based on previous research in which headspace components of heroin were analyzed by the use of SPME- GC/MS and showed that the most common volatile organic compounds (VOCs) present were: acetic acid, acetone, chloroform, hexane, diethyl ether, methanol, ethanol, toluene, benzene, and ethyl acetate. Here we present the VOCs present in seven real heroin drug samples and investigated which of these VOCs most likely produces an alert by narcotic detector canines. Optimal results were obtained when the headspace of 100µg of heroin powder samples were extracted at room temperature for 1 hour by the use of a DVB/CAR/PDMS coated SPME fiber. The dominant VOCs were presented both as individual compounds and as mixtures to certified canine teams to determine if a specific compound or mixture of compounds produced an alert. The response of each canine was monitored and recorded. According to the recorded data, none of the volatile organic compounds produced a positive alert; however, canines did show special interest in chloroform and benzene samples.
A total of 7 heroin samples were analyzed. Samples were obtained from the Miami-Dade Police Department and the Drug Enforcement Administration
Table 3: Heroin Sample Mass Information
Samples #1 and #5 were placed in separate 10ml vials. The rest of the samples were placed into individual 100ml vials.
Chemicals used throughout this study were: acetic acid, acetone, chloroform, hexane, diethyl ether, methanol, ethanol, toluene, benzene and ethyl acetate (Fisher Scientific and Sigma-Aldrich, USA).
SPME Fibers used were 50/30 µm DVB/CAR/PDMS (Supelco, Bellefonte, PA).
Sigma-pseudo scent cages and sterile gauze pads 2x2 in-8 ply 5.1x5.1cm (IMCO, Daytona Beach, FL) were used to present samples of volatiles to canines.
A total run time of 34 minutes was used for the instrumental analysis with a maximum temperature of 250°C. The GC–MS instrument was an Agilent 6890N coupled to a 5973Network Mass Selective Detector. The GC was fitted with a HP-5, 5% Phenyl Methyl Siloxane capillary column of 28.5 m x 250 mm x 0.25 µm film thickness.
The mass spectra was recorded in the total ion current mass 30 to 250 amu. The temperature of the MS transfer line and ion source was kept at 280°C and 230°C, respectively. Compounds were identified by comparing their retention times and mass spectra with those of certified standards.
Figures 3-5: Chromatograms of Headspace Analysis from Heroin Samples
Chromatographic Analysis of Standard Compounds
Fig 6. Retention time of Standards
SAMPLES #1 #2 #3 #4 #5 #6 #7
AMOUNT
100µg
28gm
18.8gm
6.10gm
20gm
Table 1. Most Common Volatile Compounds Found in Headspace Analysis of Heroin Sampling
Compound
Mol. Weight (g/mol)
*Ret.
Time
(min)
Boiling point
(ºC)
Vapor pressure at 20º C
(mmHg)
Acetic acid
60.05
2.258 
118.1
11.26
Toluene
92.14 
4.018 
110.6 22
Benzene
78.11 
2.398 
80.1 75
Ethanol
46.07
1.433 
78.4
59.3
Ethyl acetate
88.10 
1.958 
77.1 73
Hexane
86.18 
1.851 
69.0
132
Methanol
32.04 
1.376 
64.7 97
Chloroform
119.4
2.010 
62.0
159
Acetone
58.08 
1.515 
56.5
181.72
Diethyl ether
74.12 
1.562 
34.6
439.5
1. Ethyl acetate (1.958)
2. Chloroform (2.010)
3. Acetic acid (2.258)
4. Benzene (2.398)
5. Toluene (4.018)
INTRODUCTION
Heroin is a narcotic analgesic opiate that is synthesized from morphine, a naturally occurring substance extracted from the seed pod of the Asian opium poppy plant. Heroin is an addictive drug that is prepared readily by acetylation of morphine. It is synthesized by acetylation of the two hydroxyl groups of morphine with acetyl chloride.
The purpose of this study was to identify the volatile organic compounds present in heroin that can be detected by narcotics canines with the use of Solid Phase Micro-Extraction (SPME) coupled to Gas Chromatography/Mass Spectrometry (GC/MS). The SPME fiber is a solvent-less alternative to conventional sample extraction techniques. SPME is a thin fiber that is coated with an absorbing/adsorbing polymer housed in a syringe-like device that can be exposed and retracted. Once the fiber is exposed, the analytes are concentrated onto the fiber, retracted and then delivered into the GC via the injection port where the compounds are desorbed from the fiber and then enter the column where they are separated and then identified via a mass spectrometer. .
IS THIS HEROIN???
DISCUSSION/CONCLUSION
As expected, acetic acid was present in all samples due to the heroin deacetylation process which is responsible for heroin having its characteristic odor (i.e vinegar).
Discussion:
The most abundant VOC present in all Heroin samples analyzed was acetic acid; however the canines did not alert to acetic acid alone.
Heroin samples should be evaluated to determine if a secondary compound is present that could be used in combination with acetic acid to help aid in distinguishing other sources that contain acetic acid, such as vinegar.
Compounds or mixtures should be presented to canines for detection in different concentrations in order to identify which specific amount is the optimal amount to obtain an alert.
The benefits of such identification can result in pseudo canine training aids that may be used in place of real drug samples during routine canine training for law enforcement which can lead to improved canine team performance.
Conclusions:
Heroin is one of the world's most dangerous and addictive drugs that are associated with international smuggling and is a primary source of income for drug cartels and organized crime. For these reasons it has become increasingly evident that specially trained canines can be effectively utilized in a variety of tasks involving olfactory detection of such illegal substances.
This study has been conducted to determine the volatile organic compounds (VOCs) that are present in heroin, as well as to determine which of the compounds result in canine alerts.
None of the expected compounds had produced a canine alert, but canines did show interest in chloroform and benzene samples.
Vinegar and acetic acid were evaluated to determine whether either compound possessed a common secondary compound that can aid in the differentiation of one compound from another (Figures 8 and 9).
Comparison of Heroin Samples with Vinegar
FIG. 7
FIG. 8
Acetic acid and benzene were identified with the greatest abundance in the collected samples.
Common volatile organic compounds extracted from all heroin samples included acetic acid, while compounds such as benzene and ethyl acetate were found in at least two of the 7 samples; other compounds were not detected possibly due to the samples being aged.
Comparison of retention times obtained from the VOCs of the 7 heroin samples with standards were very similar except for acetic acid.
The retention time for acetic acid was close to the value obtained for acetic acid within the vinegar sample: and min., respectively.
The mixtures presented to canine teams were : (1) acetic acid, chloroform, and benzene (2) acetic acid, ethyl acetate, and benzene (3) vinegar, chloroform, ethyl acetate, and benzene. Individual compounds given were: chloroform, benzene, and ethyl acetate. A positive control ( real heroin sample ) was used to verify canine team performance.
FIG 1. Chemical structure of Heroin. The OCOCH3 groups that replaced the -OH groups in morphine are shown in red.
Vinegar: 2.057
SAMPLES #1 #2 #3 #4 #5 #6 #7
VOLATILES
Acetic acid X
Chloroform
Ethyl acetate
Benzene
Table 2. Summary of Volatiles Detected from the 7 Heroin Samples
REFERENCES
Macias, M. A. The development of an optimized system of narcotic and explosive contraband mimics for calibration and training of biological detectors. Ph.D. Dissertation. Florida International University, 2009
Chiarotti M, Fucci N. Analysis of volatile compounds in heroin samples. Forensic Sci. Int. 1988; 37(1):
Chiarotti, M.; Fucci, N.; Furnari, C. Comparative-Analysis of Illicit Heroin Samples. Forensic Sci. Int. 1991; 50 (1):
Furton KG, Hong YC, Hsu YL, Luo T, Rose S, Walton J. Identification of odor signature chemicals in cocaine using solid-phase micro-extraction-gas chromatography and detector-dog response to isolated compounds spiked on U.S paper currency. J.of Chromatogra. Sci. 2000; 40(3):
Pragst F. Application of solid-phase micro-extraction in analytical toxicology. J Chem. 2007; 388(7):
Neumann, H. Comparison of Heroin by Capillary Gas-Chromatography in Germany. Forensic Science International 1994; 69 (1): 7-16.
ACKNOWLEDGEMENTS
The authors would like to thank the Miami-Dade Canine Unit and Police Department for their contributions in both, the heroin samples and canine teams used for this study. Special thanks to Corp. Pierre Ouang Jr. of Miami Dade Corrections.
FIG 2. SPME analysis followed by GC/MS