Drug Chemistry
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Controlled Substances

The Drug Analysis Section of the I-MCFSA Chemistry Unit analyzes substances suspected of containing a controlled substance under Indiana Code, Title 35, and Article 48. Forensic chemists are responsible for the control and security of the evidence upon which they are working, furthermore, each individual chemist processes, analyzes, and interprets each assigned case. Case conclusions are formalized in a written report, which is issued to the submitting agency.
 
In 2010, 4831 cases, 37% of all cases submitted to the Crime Lab for analysis were controlled substance cases. Samples submitted come in various shapes, sizes and forms. They can include powders, liquids, tablets, capsules, LSD blotter paper and plants as well as illegal mushrooms. The cases that come into the I-MCFSA Chemistry Unit range in size from small milligram samples to multiple pounds or kilograms of illegal drugs.
 

The most commonly analyzed illegal drug we see in the Crime Lab is marijuana. More than 50% of the drug cases submitted for analysis at the Crime Lab request marijuana testing. The second most commonly analyzed drug we encounter is cocaine (especially crack cocaine). Other drugs analyzed by the l-MCFSA Crime Lab include narcotics like heroin, hydrocodone (Vicodin) and oxycodone (Oxycontin); stimulants such as methamphetamine; hallucinogens such as BZP and MDMA (ecstasy); depressants like Valium and Xanax.
 
Controlled substances are routinely screened using color tests and ultraviolet spectrophotometry (UV) with identification by gas chromatography/mass spectrometry (GC/MS). Additionally, a technique such as infrared spectrophotometry (FTIR) may also be used.
Combinations of different tests are performed on unknown material until the analyst can identify or eliminate the presence of any controlled substance. To identify the presence of a controlled substance, generally, the analyst will perform presumptive tests then using that information to proceed to confirmatory testing.
 
Color tests involve adding a reagent or reagents to the unknown material and observing a color change. The development of a color may indicate the presence of a drug or a class of drugs. Since more than one compound can give the same results, color tests are not specific tests, and cannot conclusively identify the presence of a compound, however, they are a good preliminary screening tool.
 
Ultraviolet Spectrometry (UV) is a very useful analytical tool used for the presumptive identification of controlled substances. It involves passing ultraviolet radiation ("light") through the unknown sample. The sample will absorb the ultraviolet radiation resulting in broad valleys and peaks referred to as an ultraviolet spectrum. Compounds give an ultraviolet spectrum based upon their absorbing functional groups known as chromophores. By comparing the spectrum of an unknown sample to the spectrum of a known reference standard, a preliminary identification of that compound can be made.
 
Infrared Spectrometry (IR) is a very important analytical tool used for the identification of controlled substances. It involves passing infrared radiation ("light") through the unknown sample. The sample will absorb the infrared radiation resulting in a series of valleys and peaks referred to as an infrared spectrum. Each compound gives a highly specific infrared spectrum. By comparing the spectrum of an unknown sample to the spectrum of a known reference standard an identification of that compound can be made.
 
Mass Spectrometry (MS) like IR is a highly specific analysis used for identification of controlled substances. Often, MS is used in combination with gas chromatography and referred to as gas chromatography/mass spectrometry (GC/MS). Gas chromatography separates a sample into its individual components. When coupled to a mass spectrometer as a detector, the sample exits the gas chromatograph and is passed to the mass spectrometer. As each component enters the mass spectrometer it is bombarded with a beam of electrons, causing the compound to fragment in a characteristic manner. This fragmentation pattern is referred to as the mass spectrum. Each compound gives a highly specific mass spectrum. By comparing that spectrum to the spectrum of an authentic reference standard, identification can be made.