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Forensic Chemistry

The OSBI Forensic Chemistry Unit is a section of the OSBI Criminalistics Division housed in four locations within the state:

  • Forensic Science Center in Edmond, OK
  • Northeastern Regional Laboratory in Tahlequah, OK 
  • Northwestern Regional Laboratory in Enid, OK 
  • Eastern Regional Laboratory in McAlester, OK 

Members of the Forensic Chemistry Unit strive to focus on applying timely and accurate methodologies using state-of-the-art instrumentation and procedures commonly practiced within the forensic science community.  The Forensic Chemistry Unit specializes in analysis of unknown powders, crystals, liquids, tablets, waxes, blotter paper, and plant material to determine the chemical identity.  

Uniform Controlled Dangerous Substances Act

The OSBI Forensic Chemistry Unit identifies and reports out substances controlled under Oklahoma state statute (Title 63). Oklahoma Statutes, Title 63, Chapter 2, Article 2 (Standards and Schedules) classifies controlled dangerous substances into Schedules I through V based upon the potential for abuse, medical use, and likelihood of abuse leading to physical or psychological dependence. Schedule I substances have the highest potential of abuse, no accepted medical use in the U.S., and the highest likelihood of abuse leading to physical or psychological dependence. Schedule V substances have the lowest potential for abuse, current accepted medical use in the U.S., and limited physical or psychological dependence.

Criminalists of the Forensic Chemistry Unit will testify in court on the findings of our analysis upon request.

Analytical Methods

Color Tests
Color tests are used presumptively to give an indication of what might be present in the sample. It also helps to determine which solvents to use in the analysis methods to follow. The color tests are similar to field test kits used by police officers. Color tests are screening tools only, therefore, additional analysis is required for identification of a substance. The OSBI Forensic Chemistry Unit utilizes Marquis and Cobalt Thiocyanate reagents. Each reagent responds to particular functional groups causing a characteristic color change depending upon the compound and its functional group.

Analysis by Gas Chromatograph (GC)
Gas chromatography is an instrumental analysis that separates the components of a mixture. The GC consists of three basic parts: an injection port, a chromatographic column, and a detector. The sample is diluted into the solvent and placed into a sample vial for analysis. The sample is then introduced into the GC. The time from injection of the sample until the detector produces a signal is called the retention time. The retention time of the unknown sample can be compared to that of a known standard. The OSBI Forensic Chemistry Unit uses this information as a presumptive indication of what may be present in the sample.

Conclusive Identification by Gas Chromatograph/Mass Spectrometer (GC/MS)
The sample components are separated by the GC portion of the instrument. Each component is fragmented by an electron beam and then analyzed by the mass spectrometer. Comparison of the fragment patterns of an unknown substance to that of a known standard allows for a conclusive identification.

Conclusive Identification by Infrared Detection (IR)
A sample absorbs infrared light based on the chemical structure of its components. Infrared spectroscopy can be used to identify most organic compounds based on absorption of radiation of the mid-infrared range from 4000 to 400 wave numbers. Conclusive identification is made by analysis of a sample's spectrum against a known spectrum. Analysis can be performed on a solid sample using Fourier Transform Infrared (FTIR).

Identification of Marihuana and Hashish
Samples of a vegetative nature, green leafy substance, green leafy plants, ashes or any other submittal which is suspected to be marihuana or hashish may be examined or analyzed using a series of tests: stereomicroscopic examination, modified Duquenois-Levine examination, and thin layer chromatographic (TLC) examination. The identification of marihuana requires a positive microscopic examination, modified Duquenois-Levine examination, and TLC examination. Watch the video above for the analysis and identification of marihuana.

Resources

Contact

Forensic Science Center
800 East 2nd Street
Edmond, OK  73034
Phone: 405-330-6724
Fax: 405-330-6207

Forensic Chemistry Unit Technical Manager
Heather Schafstall
Phone: 405-330-6724
Email: heather.schafstall@osbi.ok.gov

Eastern Regional Laboratory
701 W. Carl Albert Parkway
McAlester, OK 74501
Phone: 918-423-6672
Fax: 918-423-7586

Forensic Chemistry Unit Supervisor
John Giles
Email: john.giles@osbi.ok.gov

Northeastern Regional Laboratory
1995 Airport Parkway
Tahlequah, OK 74464
Phone: 918-456-0653
Fax: 918-458-0037

Forensic Chemistry Unit Supervisor
Joe Orcutt
Email: joseph.orcutt@osbi.ok.gov

Northwestern Regional Laboratory
1305 E. Owen K. Garriot Road
Enid, OK 73701
Phone: 580-242-2600
Fax: 580-234-8707

Forensic Chemistry Unit Supervisor
Anthony Goldman
Email: anthony.goldman@osbi.ok.gov