Drug Chemistry

For more information about the Chemistry Program of the Alabama Department of Forensic Sciences

Please contact:

Andrea Headrick
Chemistry Discipline Chief
2026 Valleydale Road
Hoover, AL 35244-2095
205-982-9292 ext. 229
 

For drug evidence submission information, please click here.

The Alabama Department of Forensic Sciences Drug Chemistry Discipline operates in five laboratory locations to include: Huntsville, Birmingham/Hoover, Montgomery, Auburn, and Mobile.

The Drug Chemistry Discipline is charged with the mission of identifying controlled substances, non-controlled substances, precursor chemicals, and other chemicals used in the manufacture of illegal drugs. To accomplish this mission the drug chemistry section utilizes a variety of extraction methodologies and analytical instruments.

The Alabama Department of Forensic Sciences currently receives approximately 33,000 cases annually. The distribution of cases by reported analyte for fiscal year 2017 is represented below:

For a list of ADPH controlled substance, please click here.

Items submitted for testing could include a combination of one or more of the following technologies:

Physical Examination

All items will undergo visual examination. The following observations are noted if applicable: type of material, color, size, shape, amount, morphology, significant markings, and texture.

Once the physical drug form (solid, liquid, residue, plant material, tablet, etc…) is established presumptive and confirmation methodologies can be performed. If quantity allows, all data generated must come from two separate samplings using at least two independent tests to include MS analysis.

PRESUMPTIVE METHODOLOGIES

Pharmaceutical Identifiers

Commercially prepared pills, tablets, and manufactured sealed capsules possess unique pharmaceutical identifier information both in the general appearance and inscriptions/markings of the pharmaceutical preparation. Pharmaceutical identifiers are utilized to separate visually consistent populations of commercially prepared pills, tablets, and manufactured sealed capsules for analysis.

Macroscopic/Microscopic Examination

The presumptive identification of marihuana is based upon a visual exam (macroscopic/microscopic) of submitted plant material for botanical characteristics present in the marihuana plant.

Microcrystalline Tests

A microcrystalline test is a presumptive test in which there is a chemical reaction (precipitation reaction) between a substance and a reagent that yields a crystal formation that can be observed microscopically.

The major advantages of a microcrystalline test are: rapid and simple procedure, high sensitivity, can be conducted on unextracted samples, can be utilized to distinguish isomers of certain drugs, and crystals formed are actual crystals of the drug.

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DART-TOF Mass Spectrometry (Preferred Method)

Direct analysis in real time (DART) is an open air ionization technique. The open air source allows sampling of solids, liquids, and gases through surface ionization of the test material. The ion source is coupled to an accurate time-of-flight mass spectrometer giving quick analysis of molecular ions with little to no sample preparation.

CONFIRMATION METHODOLOGIES

Infrared Spectroscopy

Infrared spectroscopy (IR) is most frequently used as a tool for structural identification of an organic compound but may be used for identification of inorganic compounds or as a screening procedure for an unknown compound. In infrared spectroscopy, an organic molecule is exposed to infrared radiation containing wavelengths from 4000cm-1 to 400 cm-1. When the frequency of the infrared light matches a frequency of vibration within the molecule, absorption occurs and is translated electronically and recorded on a data system. The resulting spectrum will have characteristic absorption bands corresponding to each of the vibrations among the atoms in the molecule. Infrared spectra are acquired on an instrument known as the Fourier Transform Infrared Spectrophotometer (FTIR). An FTIR instrument collects the spectrum in the time domain and mathematically transforms it to the frequency domain.

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Infrared spectrum for Cocaine base

Gas Chromatograph/Infrared Spectrophotometer (GC/IR)

Hyphenated instruments such as a gas chromatograph/infrared spectrophotometer (GC/IR) are instruments capable of incorporating two types of techniques for sample identification. In this case, a gas chromatograph is utilized to separate sample components from a mixture by the partitioning of the analyte of interest between two phases: a mobile phase and a stationary phase. An infrared spectrophotometer is then utilized to detect molecular interactions of sample components with infrared light.

GC/IRD vapor phase Spectrum for Cocaine

Gas Chromatograph/Mass Spectrometer (GC/MS)

Gas chromatograph is an instrument that separates a mixture of compounds utilizing two phases, the mobile phase is an inert gas and the analytes (in gas form) are separated based on physical and chemical interactions with the stationary phase. A Mass Spectrometer is an instrument that measures the mass to charge ratio (m/z) and relative abundances of ions for identification of chemical compounds. A gas chromatograph/mass spectrometer is a two part instrument that combines the separation capabilities of a gas chromatograph with the compound selectivity of the mass spectrometer.

Mass Spectrum for Cocaine

Derivatization for Gas Chromatograph/Mass Spectrometer

Chemical derivatization before analysis is generally performed for one of three reasons:

1. To make a compound more suitable for analysis by a particular method. The derivatization procedure modifies the chemical structure of the compound so that it can be analyzed by the desired technique (ex. change volatility, adsorption and/or thermal stability).

2. To improve the analytical efficiency of a compound. Interactions between the compounds themselves (mixtures) or the compounds with the chromatographic column can lead to poor peak shape and poor peak resolution. Compounds that co-elute or are poorly resolved from other sample components can be resolved of one or more of them are converted to an appropriate derivative.

3. To improve the detectability of a compound, the derivatization procedure increases detectability by increasing the bulk of the compound or by introducing atoms or functional groups that are exploited by the detector.

DART-QTRAP

Direct analysis in real time (DART) is an open air ionization technique. The open air source allows sampling of solids, liquids, and gases through surface ionization of the test material. The ion source is coupled to a hybrid triple quadrupole/ion trap mass spectrometer giving quick analysis of samples with little to no sample preparation.

FIRE DEBRIS

The Alabama Department of Forensic Sciences Fire Debris section of the Chemistry Discipline operates in one laboratory location to include: Birmingham/Hoover.

The Fire Debris section is charged with the mission of identifying the presence or absence of ignitable liquids. To accomplish this mission the fire debris section utilizes a variety of extraction methodologies and analytical instruments.

Items submitted for testing will undergo extraction procedures and Gas Chromatograph/Mass Spectrometer (GC/MS) analyses.

Sample Extraction Procedures could include the following:

1. Cold/Heated Headspace
2. Direct Injection of Dilutions
3. Passive Headspace Concentration with Activated Charcoal
4 .Solvent Extraction
5. Vegetable Oil Analysis

Gas Chromatograph/Mass Spectrometer (GC/MS)

Gas chromatograph is an instrument that separates a mixture of compounds utilizing two phases, the mobile phase is an inert gas and the analytes (in gas form) are separated based on physical and chemical interactions with the stationary phase. A Mass Spectrometer is an instrument that measures the mass to charge ratio (m/z) and relative abundances of ions for identification of chemical compounds. A gas chromatograph/mass spectrometer is a two part instrument that combines the separation capabilities of a gas chromatograph with the compound selectivity of the mass spectrometer.

 

Total Ion Chromatogram for Gasoline

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